Ccnb1

UniProt ID: P24860
Organism: Mus musculus
Review Status: COMPLETE
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Gene Description

Cyclin B1 is the non-catalytic regulatory cyclin that binds and activates CDK1 in the cyclin B1-CDK1 complex to drive mitotic entry and progression through G2/M. Its abundance and localization are tightly cell-cycle regulated, with cytoplasmic accumulation followed by nuclear and centrosomal/spindle-associated pools during mitosis. The cyclin B1-CDK1 complex phosphorylates mitotic substrates and also has a non-core mitochondrial pool that coordinates respiration with G2/M progression. Ccnb1 is essential for embryonic development, while many tissue-specific proliferation phenotypes are downstream consequences of its core cell-cycle role.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0000082 G1/S transition of mitotic cell cycle
IBA
GO_REF:0000033
MODIFY
Summary: The existing annotation captures cell-cycle or phosphorylation biology but uses an inaccurate or overly broad term for cyclin B1.
Reason: The source term says negative regulation of protein phosphorylation, but cyclin B1 promotes mitotic entry through the cyclin B1-CDK1 complex. The replacement keeps this as a biological-process correction focused on G2/M transition rather than as a molecular-function claim about CDK activation.
Supporting Evidence:
file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
Cyclin B1 is the major regulatory partner of CDK1, forming the CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis entry.
GO:0005634 nucleus
IBA
GO_REF:0000033
UNDECIDED
Summary: PMID:17325031 supports cyclin B1 accumulation in metaphase-arrested embryos, but the cached abstract does not directly establish nuclear localization.
Reason: Cyclin B1 nuclear localization is biologically plausible, but this evidence row needs direct localization support from the full text or another source before acceptance.
GO:0005737 cytoplasm
IBA
GO_REF:0000033
UNDECIDED
Summary: PMID:17325031 supports cyclin B1 accumulation in metaphase-arrested embryos, but the cached abstract does not directly establish cytoplasmic localization.
Reason: Cyclin B1 cytoplasmic localization is biologically plausible, but this evidence row needs direct localization support from the full text or another source before acceptance.
GO:0016538 cyclin-dependent protein serine/threonine kinase regulator activity
IBA
GO_REF:0000033
MODIFY
Summary: The existing annotation captures cell-cycle or phosphorylation biology but uses an inaccurate or overly broad term for cyclin B1.
Reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the replacement term better represents the supported G2/M or CDK-activation role.
Supporting Evidence:
file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
Cyclin B1's primary molecular role is to activate and localize CDK1 kinase activity to initiate and orchestrate M-phase events.
GO:0005815 microtubule organizing center
IBA
GO_REF:0000033
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0005759 mitochondrial matrix
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0097125 cyclin B1-CDK1 complex
IBA
GO_REF:0000033
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
Supporting Evidence:
file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
Cyclin B1 is the major regulatory partner of CDK1, forming the CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis entry.
GO:0007080 mitotic metaphase chromosome alignment
IBA
GO_REF:0000033
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
Supporting Evidence:
file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
Cyclin B1 localizes to unattached kinetochores and contributes to efficient microtubule attachment and proper chromosome alignment during mitosis.
GO:0005634 nucleus
IEA
GO_REF:0000120
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0005737 cytoplasm
IEA
GO_REF:0000120
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0005813 centrosome
IEA
GO_REF:0000120
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0016538 cyclin-dependent protein serine/threonine kinase regulator activity
IEA
GO_REF:0000002
MODIFY
Summary: The existing annotation captures cell-cycle or phosphorylation biology but uses an inaccurate or overly broad term for cyclin B1.
Reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the replacement term better represents the supported G2/M or CDK-activation role.
GO:0044772 mitotic cell cycle phase transition
IEA
GO_REF:0000002
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0051301 cell division
IEA
GO_REF:0000043
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0000922 spindle pole
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0000940 outer kinetochore
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0001556 oocyte maturation
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0005113 patched binding
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0005759 mitochondrial matrix
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0005829 cytosol
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0007052 mitotic spindle organization
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0007080 mitotic metaphase chromosome alignment
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0007283 spermatogenesis
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0009410 response to xenobiotic stimulus
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0009612 response to mechanical stimulus
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0009636 response to toxic substance
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0010629 negative regulation of gene expression
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0010971 positive regulation of G2/M transition of mitotic cell cycle
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0019901 protein kinase binding
IEA
GO_REF:0000120
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0031442 positive regulation of mRNA 3'-end processing
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0042246 tissue regeneration
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0044389 ubiquitin-like protein ligase binding
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0045931 positive regulation of mitotic cell cycle
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0046680 response to DDT
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0048565 digestive tract development
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0051987 positive regulation of attachment of spindle microtubules to kinetochore
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0055015 ventricular cardiac muscle cell development
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0060045 positive regulation of cardiac muscle cell proliferation
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0060623 regulation of chromosome condensation
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0061575 cyclin-dependent protein serine/threonine kinase activator activity
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0065003 protein-containing complex assembly
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0071283 cellular response to iron(III) ion
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0071398 cellular response to fatty acid
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0071456 cellular response to hypoxia
IEA
GO_REF:0000107
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0090266 regulation of mitotic cell cycle spindle assembly checkpoint
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0097125 cyclin B1-CDK1 complex
IEA
GO_REF:0000107
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:1905448 positive regulation of mitochondrial ATP synthesis coupled electron transport
IEA
GO_REF:0000107
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0001933 negative regulation of protein phosphorylation
ISO
GO_REF:0000096
MODIFY
Summary: The existing annotation captures cell-cycle or phosphorylation biology but uses an inaccurate or overly broad term for cyclin B1.
Reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the replacement term better represents the supported G2/M or CDK-activation role.
GO:0005634 nucleus
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0045860 positive regulation of protein kinase activity
ISO
GO_REF:0000096
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0000922 spindle pole
ISO
GO_REF:0000119
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0000940 outer kinetochore
ISO
GO_REF:0000119
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0001556 oocyte maturation
ISO
GO_REF:0000096
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0005113 patched binding
ISO
GO_REF:0000119
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0005737 cytoplasm
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0005759 mitochondrial matrix
ISO
GO_REF:0000119
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0005813 centrosome
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0005829 cytosol
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0007052 mitotic spindle organization
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0007080 mitotic metaphase chromosome alignment
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0010629 negative regulation of gene expression
ISO
GO_REF:0000096
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0010971 positive regulation of G2/M transition of mitotic cell cycle
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0019901 protein kinase binding
ISO
GO_REF:0000096
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0019901 protein kinase binding
ISO
GO_REF:0000119
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0031442 positive regulation of mRNA 3'-end processing
ISO
GO_REF:0000096
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
GO:0044389 ubiquitin-like protein ligase binding
ISO
GO_REF:0000119
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0044877 protein-containing complex binding
ISO
GO_REF:0000096
MODIFY
Summary: The existing annotation captures cell-cycle or phosphorylation biology but uses an inaccurate or overly broad term for cyclin B1.
Reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the replacement term better represents the supported G2/M or CDK-activation role.
GO:0045931 positive regulation of mitotic cell cycle
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0051987 positive regulation of attachment of spindle microtubules to kinetochore
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0060045 positive regulation of cardiac muscle cell proliferation
ISO
GO_REF:0000096
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0060623 regulation of chromosome condensation
ISO
GO_REF:0000096
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0061575 cyclin-dependent protein serine/threonine kinase activator activity
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0065003 protein-containing complex assembly
ISO
GO_REF:0000096
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0090266 regulation of mitotic cell cycle spindle assembly checkpoint
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0097125 cyclin B1-CDK1 complex
ISO
GO_REF:0000119
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:1905448 positive regulation of mitochondrial ATP synthesis coupled electron transport
ISO
GO_REF:0000119
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
GO:0005515 protein binding
IPI
PMID:12124778
GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with...
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
Supporting Evidence:
PMID:12124778
GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with a role in S and G2/M cell cycle checkpoints induced by genotoxic stress.
GO:0005759 mitochondrial matrix
IDA
PMID:24746669
Cyclin B1/Cdk1 coordinates mitochondrial respiration for cel...
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
Supporting Evidence:
PMID:24746669
Cyclin B1/Cdk1 coordinates mitochondrial respiration for cell-cycle G2/M progression.
GO:0005634 nucleus
IDA
PMID:17325031
Loss of Cdc20 causes a securin-dependent metaphase arrest in...
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
Supporting Evidence:
PMID:17325031
Loss of Cdc20 causes a securin-dependent metaphase arrest in two-cell mouse embryos.
GO:0005737 cytoplasm
IDA
PMID:17325031
Loss of Cdc20 causes a securin-dependent metaphase arrest in...
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
Supporting Evidence:
PMID:17325031
Loss of Cdc20 causes a securin-dependent metaphase arrest in two-cell mouse embryos.
GO:0045787 positive regulation of cell cycle
IDA
PMID:22053081
Upregulation of Cyclin B1 by miRNA and its implications in c...
MODIFY
Summary: The existing annotation captures cell-cycle or phosphorylation biology but uses an inaccurate or overly broad term for cyclin B1.
Reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the replacement term better represents the supported G2/M or CDK-activation role.
Supporting Evidence:
PMID:22053081
Upregulation of Cyclin B1 by miRNA and its implications in cancer.
GO:0048146 positive regulation of fibroblast proliferation
IMP
PMID:22053081
Upregulation of Cyclin B1 by miRNA and its implications in c...
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
Supporting Evidence:
PMID:22053081
Upregulation of Cyclin B1 by miRNA and its implications in cancer.
GO:0016020 membrane
IDA
PMID:9539739
Cyclin B2-null mice develop normally and are fertile whereas...
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
Supporting Evidence:
PMID:9539739
Cyclin B2-null mice develop normally and are fertile whereas cyclin B1-null mice die in utero.
GO:0005813 centrosome
ISS
GO_REF:0000024
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
GO:0005634 nucleus
IDA
PMID:19376971
Role of Filia, a maternal effect gene, in maintaining euploi...
REMOVE
Summary: The cited Filia paper does not support Ccnb1 nuclear localization.
Reason: PMID:19376971 describes Filia effects on spindle assembly and checkpoint regulators in embryos, not cyclin B1 localization. Cyclin B1 nuclear localization is supported elsewhere, but this evidence assertion should not be retained.
Supporting Evidence:
PMID:19376971
Role of Filia, a maternal effect gene, in maintaining euploidy during cleavage-stage mouse embryogenesis.
GO:0005634 nucleus
IDA
PMID:16489008
Patched1 functions as a gatekeeper by promoting cell cycle p...
ACCEPT
Summary: Supported core cyclin B1/CDK1 mitotic function or a well-established mitotic localization.
Reason: This term is consistent with cyclin B1 as the regulatory subunit of the cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
Supporting Evidence:
PMID:16489008
Patched1 functions as a gatekeeper by promoting cell cycle progression.
GO:0001701 in utero embryonic development
IMP
PMID:9539739
Cyclin B2-null mice develop normally and are fertile whereas...
KEEP AS NON CORE
Summary: Supported but context-specific or downstream cyclin B1 biology.
Reason: The annotation is compatible with the literature, but it reflects a localization, interaction, developmental consequence, or noncanonical mitochondrial role rather than the primary CDK1-activation function.
Supporting Evidence:
PMID:9539739
Cyclin B2-null mice develop normally and are fertile whereas cyclin B1-null mice die in utero.
GO:0005634 nucleus
ISO
PMID:16109376
The bromodomain protein Brd4 is a positive regulatory compon...
REMOVE
Summary: The cited P-TEFb paper does not support Ccnb1 nuclear localization.
Reason: PMID:16109376 is about Brd4/P-TEFb, cyclin T1, and CDK9 biology, not Ccnb1/cyclin B1 localization. Cyclin B1 nuclear localization is supported elsewhere, but this evidence assertion should not be retained.
Supporting Evidence:
PMID:16109376
The bromodomain protein Brd4 is a positive regulatory component of P-TEFb and stimulates RNA polymerase II-dependent transcription.
GO:0005634 nucleus
IDA
PMID:14993286
Cyclin F disruption compromises placental development and af...
REMOVE
Summary: The cited cyclin F paper does not support Ccnb1 nuclear localization.
Reason: PMID:14993286 describes cyclin F disruption and related cell-cycle defects, not Ccnb1/cyclin B1 localization. Cyclin B1 nuclear localization is supported elsewhere, but this evidence assertion should not be retained.
Supporting Evidence:
PMID:14993286
Cyclin F disruption compromises placental development and affects normal cell cycle execution.
GO:0006468 protein phosphorylation
IDA
PMID:12124778
GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with...
MODIFY
Summary: The existing annotation captures cell-cycle or phosphorylation biology but uses an inaccurate or overly broad term for cyclin B1.
Reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the replacement term better represents the supported G2/M or CDK-activation role.
Supporting Evidence:
PMID:12124778
GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with a role in S and G2/M cell cycle checkpoints induced by genotoxic stress.
GO:0005515 protein binding
IPI
PMID:12525704
RFPL4 interacts with oocyte proteins of the ubiquitin-protea...
MARK AS OVER ANNOTATED
Summary: The term is weakly informative or extrapolated relative to the core evidence.
Reason: This annotation is not the best representation of cyclin B1 function and likely reflects a broad computational transfer, stress-expression correlation, or vague binding term.
Supporting Evidence:
PMID:12525704
RFPL4 interacts with oocyte proteins of the ubiquitin-proteasome degradation pathway.

Core Functions

Cyclin B1 activates and targets CDK1 in the cyclin B1-CDK1 complex to drive G2/M transition and mitotic progression.

Supporting Evidence:
  • file:mouse/Ccnb1/Ccnb1-uniprot.txt
    Essential for the control of the cell cycle at the G2/M
  • file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
    Cyclin B1 is the major regulatory partner of CDK1, forming the CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis entry, including nuclear envelope breakdown (NEBD) and spindle formation.
  • file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
    Cyclin B1 accumulates in S/G2 and shuttles cytoplasm to nucleus, becoming concentrated in the nucleus at late G2/prophase. During prometaphase it localizes to centrosomes, mitotic spindle, chromosome arms, and unattached kinetochores.

References

Gene Ontology annotation through association of InterPro records with GO terms
Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Automated transfer of experimentally-verified manual GO annotation data to mouse-rat orthologs
Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara
Automated transfer of experimentally-verified manual GO annotation data to mouse-human orthologs
Combined Automated Annotation using Multiple IEA Methods
GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with a role in S and G2/M cell cycle checkpoints induced by genotoxic stress.
RFPL4 interacts with oocyte proteins of the ubiquitin-proteasome degradation pathway.
Cyclin F disruption compromises placental development and affects normal cell cycle execution.
The bromodomain protein Brd4 is a positive regulatory component of P-TEFb and stimulates RNA polymerase II-dependent transcription.
Patched1 functions as a gatekeeper by promoting cell cycle progression.
Loss of Cdc20 causes a securin-dependent metaphase arrest in two-cell mouse embryos.
Role of Filia, a maternal effect gene, in maintaining euploidy during cleavage-stage mouse embryogenesis.
Upregulation of Cyclin B1 by miRNA and its implications in cancer.
Cyclin B1/Cdk1 coordinates mitochondrial respiration for cell-cycle G2/M progression.
Cyclin B2-null mice develop normally and are fertile whereas cyclin B1-null mice die in utero.
file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
Falcon deep research synthesis for mouse Ccnb1
  • Cyclin B1 is the major CDK1 regulatory cyclin driving G2/M transition and mitotic entry, with dynamic cytoplasmic, nuclear, centrosomal, spindle, and kinetochore localization.
    "Cyclin B1 is the major regulatory partner of CDK1, forming the CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis entry, including nuclear envelope breakdown (NEBD) and spindle formation."

📚 Additional Documentation

Deep Research Falcon

(Ccnb1-deep-research-falcon.md)

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template_variables:
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gene_id: Ccnb1
gene_symbol: Ccnb1
uniprot_accession: P24860
protein_description: 'RecName: Full=G2/mitotic-specific cyclin-B1;'
gene_info: Name=Ccnb1; Synonyms=Ccn-2, Ccnb1-rs13, Cycb, Cycb1;
organism_full: Mus musculus (Mouse).
protein_family: Belongs to the cyclin family. Cyclin AB subfamily.
protein_domains: CCNB1_first_cyclin-box. (IPR048026); Cyclin. (IPR039361); Cyclin-like_dom.
(IPR013763); Cyclin-like_sf. (IPR036915); Cyclin_A/B-like. (IPR046965)
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Question

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

  • UniProt Accession: P24860
  • Protein Description: RecName: Full=G2/mitotic-specific cyclin-B1;
  • Gene Information: Name=Ccnb1; Synonyms=Ccn-2, Ccnb1-rs13, Cycb, Cycb1;
  • Organism (full): Mus musculus (Mouse).
  • Protein Family: Belongs to the cyclin family. Cyclin AB subfamily.
  • Key Domains: CCNB1_first_cyclin-box. (IPR048026); Cyclin. (IPR039361); Cyclin-like_dom. (IPR013763); Cyclin-like_sf. (IPR036915); Cyclin_A/B-like. (IPR046965)

MANDATORY VERIFICATION STEPS:

  1. Check if the gene symbol "Ccnb1" matches the protein description above
  2. Verify the organism is correct: Mus musculus (Mouse).
  3. Check if protein family/domains align with what you find in literature
  4. If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'Ccnb1' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information

Research Target:

Please provide a comprehensive research report on the gene Ccnb1 (gene ID: Ccnb1, UniProt: P24860) in mouse.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Output

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on:
1. Key concepts and definitions with current understanding
2. Recent developments and latest research (prioritize 2023-2024 sources)
3. Current applications and real-world implementations
4. Expert opinions and analysis from authoritative sources
5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available.
Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

  • UniProt Accession: P24860
  • Protein Description: RecName: Full=G2/mitotic-specific cyclin-B1;
  • Gene Information: Name=Ccnb1; Synonyms=Ccn-2, Ccnb1-rs13, Cycb, Cycb1;
  • Organism (full): Mus musculus (Mouse).
  • Protein Family: Belongs to the cyclin family. Cyclin AB subfamily.
  • Key Domains: CCNB1_first_cyclin-box. (IPR048026); Cyclin. (IPR039361); Cyclin-like_dom. (IPR013763); Cyclin-like_sf. (IPR036915); Cyclin_A/B-like. (IPR046965)

MANDATORY VERIFICATION STEPS:

  1. Check if the gene symbol "Ccnb1" matches the protein description above
  2. Verify the organism is correct: Mus musculus (Mouse).
  3. Check if protein family/domains align with what you find in literature
  4. If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'Ccnb1' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information

Research Target:

Please provide a comprehensive research report on the gene Ccnb1 (gene ID: Ccnb1, UniProt: P24860) in mouse.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Research Report: Mouse Ccnb1 (Cyclin B1; UniProt P24860) Functional Annotation

0. Target verification (mandatory)

The requested target is Mus musculus cyclin B1, encoded by Ccnb1 and annotated in UniProt as P24860 (“G2/mitotic-specific cyclin-B1”). The literature synthesized here explicitly refers to mouse Ccnb1/CCNB1 and experimentally distinguishes it from paralogs Ccnb2 (cyclin B2) and Ccnb3 (cyclin B3) in genetic and mechanistic contexts (e.g., oocyte- and germline-specific deletions). Cyclin B1 is consistently described as the canonical B-type cyclin that binds CDK1 to form maturation-promoting factor (MPF) and is regulated by APC/C-mediated proteolysis. (chotiner2019functionsofcyclins pages 5-6, tang2017requirementforccnb1 pages 1-2, chen2022septin4controls pages 1-2)

1. Key concepts and definitions (current understanding)

1.1 Cyclin B1 as the CDK1 regulatory subunit (MPF)

Cyclin B1 is the major regulatory partner of CDK1, forming the CDK1–cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis entry, including nuclear envelope breakdown (NEBD) and spindle formation. (chotiner2019functionsofcyclins pages 5-6, chen2022septin4controls pages 1-2)

1.2 APC/C as the primary inactivation mechanism for cyclin B1–CDK1 activity

Mitotic and meiotic progression depends on timed cyclin B1 destruction by the anaphase-promoting complex/cyclosome (APC/C). In mouse oocytes, APC/C with CDH1/FZR1 restrains cyclin B1 accumulation during GV (prophase I) arrest, whereas APC/C–CDC20 is dominant at metaphase-to-anaphase transitions, targeting cyclin B1 (and securin) for degradation. (chen2022septin4controls pages 1-2, li2018cyclinb2can pages 7-8)

1.3 Subcellular localization as a key layer of cyclin B1 regulation

Cyclin B1 is spatially regulated: it shuttles between cytoplasm and nucleus and becomes nuclear at mitotic entry; during prometaphase it localizes to the spindle, centrosomes, chromosomes, and is enriched on unattached kinetochores, which can influence attachment and checkpoint signaling. (chen2008cyclinb1is pages 1-2, chen2008cyclinb1is pages 4-5)

2. Core molecular function and pathways

2.1 Primary function: activation of CDK1 to trigger M phase

Cyclin B1’s primary molecular role is to activate and localize CDK1 kinase activity to initiate and orchestrate M-phase events. This is supported by mouse genetic essentiality (embryonic lethality with early cleavage arrest) and extensive oocyte/germline conditional deletion phenotypes consistent with failure of proper G2/M or meiotic transitions when cyclin B1 levels/activation dynamics are perturbed. (chotiner2019functionsofcyclins pages 5-6, tang2017requirementforccnb1 pages 1-2, li2018cyclinb2can pages 7-8)

2.2 Checkpoint coupling: spindle checkpoint permissiveness via MPS1 kinetochore localization

A key mechanistic link between cyclin B1–CDK1 activity and the spindle assembly checkpoint (SAC) is that CDK1–CCNB1 enables MPS1 recruitment to unattached kinetochores, establishing a “checkpoint-permissive” state; checkpoint silencing is coupled to cyclin B1 decline and phosphatase reactivation (PP2A-B55 counteraction). (li2019cyclinsregulatingoocyte pages 4-4)

2.3 APC/C timing in early embryos: early APC/C activity can weaken SAC enforcement

In early mouse embryos, APC/C activity can begin coincident with NEBD before full spindle assembly, contributing to relative SAC inefficiency; spindle perturbation (nocodazole) delays anaphase and slows cyclin B degradation. These observations directly connect cyclin-B-type reporters to APC/C timing in vivo. (horakova2024earlyonsetof pages 8-11)

3. Subcellular localization and dynamics (where CCNB1 acts)

3.1 Dynamic localization across the cell cycle

Cyclin B1 accumulates in S/G2 and shuttles cytoplasm↔nucleus, becoming concentrated in the nucleus at late G2/prophase. During prometaphase it localizes to centrosomes, mitotic spindle, chromosome arms, and is concentrated at outer plates of unattached kinetochores, especially immediately after NEBD. (chen2008cyclinb1is pages 1-2, chen2008cyclinb1is pages 4-5)

3.2 Kinetochore removal upon microtubule attachment

Cyclin B1 diminishes on aligned/attached kinetochores and can be transported from kinetochores toward spindle poles via a dynein/dynactin-dependent mechanism; this transport is promoted by microtubule attachment and is distinct from proteasome-mediated degradation at kinetochores (MG132-insensitive loss from kinetochores in the cited mechanistic study). (chen2008cyclinb1is pages 1-2, chen2008cyclinb1is pages 4-5)

3.3 Sequence determinants for localization

Domain mapping indicates modular targeting: an N-terminal domain can be sufficient/necessary for chromatin association, while C-terminal regions including the cyclin box support targeting to spindle microtubules/centrosomes/kinetochores. Importantly, disruption of the cyclin box can abolish kinetochore localization, consistent with CDK1 binding being required for some kinetochore functions. (chen2008cyclinb1is pages 10-11, bentley2007distinctsequenceelements pages 6-7)

4. Mouse genetics: essentiality and tissue-specific requirements

4.1 Early embryo requirement (global knockout)

Mouse Ccnb1-null embryos are not viable: embryos die before ~E10, and in culture can arrest in G2 at approximately the 4-cell stage after two normal divisions, consistent with an essential requirement for cyclin B1 for the G2–M transition in early embryogenesis. Maternal CCNB1 can support early cleavages, but zygotic Ccnb1 becomes essential shortly thereafter. (chotiner2019functionsofcyclins pages 5-6)

4.2 Male germline: mitotic proliferation vs meiosis

Conditional deletion evidence indicates stage specificity: ablation of Ccnb1 in gonocytes/spermatogonia causes male germ-cell depletion and sterility due to proliferation failure and increased apoptosis, whereas deletion later in premeiotic male germ cells may not impair meiosis or fertility, consistent with redundancy (e.g., CCNB2) for some meiotic functions. (tang2017requirementforccnb1 pages 1-2, chotiner2019functionsofcyclins pages 5-6)

4.3 Oocyte meiosis: redundancy in meiosis I, requirement for proper meiosis II dynamics

Oocyte-specific Ccnb1 deletion revealed that oocytes can still undergo GVBD and polar body extrusion (meiosis I) because cyclin B2 can compensate for CDK1 activation; however, cyclin B1 becomes important for correct post-meiosis-I CDK1 reactivation and metaphase II control, and Ccnb1-null females are infertile. Double Ccnb1/Ccnb2 deletion arrests oocytes at GV. (li2018cyclinb2can pages 1-2, li2018cyclinb2can pages 7-8)

4.4 Ovarian somatic cells: granulosa-cell deletion impacts embryo development rates

Granulosa-cell-specific Ccnb1 knockout causes subfertility and markedly reduces developmental progression of embryos: reported rates include 2-cell embryos 39.2% vs 86.8%, morulas 26.0% vs 85.0%, and blastocysts 19.1% vs 85.8% in mutant vs control groups; additionally, 32.4% of oocytes showed chromosome condensation/spindle disassembly after first polar body extrusion and failed to undergo second meiosis. (chen2022septin4controls pages 1-2)

5. Recent developments and latest research (prioritizing 2023–2024)

5.1 2024 (EMBO Journal): spatial APC/C control via cyclin B1 nucleosome binding

A major 2024 mechanistic advance is that cyclin B1 destruction is not only timed by SAC/APC/C signaling but also spatially organized: cyclin B1 binds nucleosomes using an N-terminal arginine anchor that contacts the nucleosome acidic patch, concentrating cyclin B1 and APC/C interaction on mitotic chromatin and the mitotic apparatus. Disrupting the arginine-anchor chromatin interaction delays cyclin B1 degradation and increases aneuploidy. Reported in vivo FCCS dissociation constants were approximately ~80 nM on chromosomes vs ~180 nM in cytoplasm (with an in vitro estimate ~63 nM), supporting stronger effective interaction on chromatin. (cirillo2024spatialcontrolof pages 13-14, cirillo2024spatialcontrolof pages 9-10, cirillo2024spatialcontrolof pages 4-6)

Publication date / URL: Aug 2024, https://doi.org/10.1038/s44318-024-00194-2 (cirillo2024spatialcontrolof pages 1-2)

5.2 2024 (Nature): cyclin B1 partnership beyond CDK1—CDK5–cyclin B1 complex

A 2024 Nature study reports that cyclin B1 can form complexes with CDK5 in addition to CDK1 during mitosis, with co-immunoprecipitation evidence supporting cyclin B1 association with both kinases and a functional role in mitotic fidelity. This expands the “cyclin B1 partners only with CDK1” view in certain mitotic contexts. (zheng2024cdk5cyclinb1regulates pages 1-4)

Publication date / URL: Sep 2024, https://doi.org/10.1038/s41586-024-07888-x (zheng2024cdk5cyclinb1regulates pages 1-4)

5.3 2024 (Nucleic Acids Research): Ccnb1 mRNA APA programs cyclin B1 accumulation during meiosis

A 2024 mouse gene-editing study shows that alternative cleavage and polyadenylation (APA) of the Ccnb1 3′UTR creates short vs long isoforms with distinct translational programs. Quantitatively, ablation of a proximal PAS (PAS1) caused an ~70% decrease in cyclin B1 protein in GV oocytes; increased PAS1 usage caused a 2–3× increase in short-UTR Ccnb1 mRNA abundance and accelerated meiotic re-entry. The work uses microinjected rescue constructs (Ccnb1 ORF fused to PAS1 3′UTR) and measures CDK1 activity via substrate phosphorylation in oocytes, directly connecting transcript isoform choice to MPF activity timing. (wang2024alternativecleavageand pages 10-12)

Publication date / URL: Dec 2024, https://doi.org/10.1093/nar/gkad1151 (wang2024alternativecleavageand pages 10-12)

5.4 2024 (Frontiers in Cell and Developmental Biology): embryo live imaging of APC/C–cyclin dynamics

A 2024 mouse embryo study used live imaging with cyclin B reporters (e.g., a “90 cyB1” fragment reporter) plus securin/histone fluorescent markers to quantify APC/C timing and SAC performance. Reported quantitative effects included nocodazole increasing an abnormal/assayed fraction from 1.07 ± 0.52% to 6.1 ± 2.28% and increasing a division-length metric from 63.2 ± 23.9% (n=51) to 293.1 ± 145.5% (n=58), along with delayed anaphase and slowed cyclin B degradation. (horakova2024earlyonsetof pages 8-11)

Publication date / URL: Mar 2024, https://doi.org/10.3389/fcell.2024.1355979 (horakova2024earlyonsetof pages 8-11)

5.5 2023 (IJMS review): synthesis of mouse-oocyte cyclin biology

A 2023 review summarizes mouse oocyte cyclin functions with cyclin B1 as the core Cdk1 partner, highlights that Ccnb1 deletion is embryonic lethal, and discusses degron motifs (D-box/KEN) and additional sequence features reported to tune meiotic timing. (kim2023meioticcellcycle pages 3-5)

Publication date / URL: Sep 2023, https://doi.org/10.3390/ijms241713659 (kim2023meioticcellcycle pages 3-5)

6. Current applications and real-world implementations

6.1 Widely used experimental readout of proliferation/mitosis

Cyclin B1 (mRNA/protein) is frequently used as a cell-cycle progression marker (G2/M-associated expression) in mouse and mammalian systems, including transcriptomic and cell-phenotyping studies, reflecting its role as an indicator of proliferative state. (tang2017requirementforccnb1 pages 1-2, kim2023meioticcellcycle pages 3-5)

6.2 Live-cell/embryo imaging reporters for APC/C activity and mitotic timing

Cyclin B1-derived fluorescent reporters (e.g., N-terminal cyclin B1 fragments, “90 cyB1”) are used in mouse embryos to monitor APC/C-driven destruction dynamics and link spindle perturbations to cyclin degradation and anaphase timing in vivo. Such reporters are microinjected as cRNAs alongside histone markers to stage mitosis. (horakova2024earlyonsetof pages 8-11)

6.3 Oocyte microinjection and gene-edited 3′UTR alleles to control meiotic timing

Mouse oocyte studies implement microinjection of engineered Ccnb1 ORF–3′UTR constructs (e.g., PAS1 3′UTR fusions) to rescue or tune meiotic re-entry timing, and use gene-edited polyadenylation-signal alleles (PAS mutations) to causally test translational control programs in vivo. (wang2024alternativecleavageand pages 10-12)

6.4 Conditional mouse genetics as a functional annotation engine

Tissue-specific Ccnb1 deletions (e.g., oocyte, germline, granulosa cell) are widely used “real-world” functional tools to separate systemic embryonic-lethal roles from gametogenesis-specific roles and to identify redundancy with Ccnb2. (li2018cyclinb2can pages 1-2, tang2017requirementforccnb1 pages 1-2, chen2022septin4controls pages 1-2)

7. Expert synthesis and analysis (authoritative perspectives)

7.1 Essentiality vs redundancy depends on developmental context

Mouse genetics supports a model where Ccnb1 is uniquely essential for early embryonic mitotic progression, whereas in some germline contexts cyclin B1 and B2 exhibit partial redundancy (particularly in oocyte meiosis I, where B2 can activate CDK1 in the absence of B1). This “essential but contextually buffered” architecture is a recurring theme in mammalian cyclin biology. (chotiner2019functionsofcyclins pages 5-6, li2018cyclinb2can pages 7-8)

7.2 Modern view of cyclin B1 regulation emphasizes spatial biochemistry

The 2024 EMBO Journal work implies that cyclin B1 regulation is not only “APC/C on/off” but also governed by where APC/C-substrate encounters occur (chromatin/spindle/centrosomes vs cytoplasm). This spatial model helps explain how cells achieve rapid, switch-like cyclin B1 destruction at anaphase onset while maintaining robust checkpoint control. (cirillo2024spatialcontrolof pages 13-14, cirillo2024spatialcontrolof pages 1-2)

7.3 Emerging expansion of cyclin B1 partner space

Evidence for CDK5–cyclin B1 complexes suggests cyclin B1 may participate in additional kinase assemblies affecting mitotic fidelity, expanding canonical network diagrams centered exclusively on CDK1. (zheng2024cdk5cyclinb1regulates pages 1-4)

8. Recent statistics and data highlights (2022–2024)

  • Granulosa-cell Ccnb1 knockout (mouse): 2-cell embryos 39.2% vs 86.8%, morulas 26.0% vs 85.0%, blastocysts 19.1% vs 85.8%; 32.4% abnormal post-PB1 spindle/chromosome phenotype. (chen2022septin4controls pages 1-2)
  • Ccnb1 APA gene editing (mouse oocytes, 2024): PAS1 ablation → ~70% decrease in cyclin B1 protein in GV oocytes; increased PAS1 usage → 2–3× more short-UTR Ccnb1 mRNA and faster meiotic re-entry. (wang2024alternativecleavageand pages 10-12)
  • Mouse embryo APC/C timing (2024): nocodazole increased a measured fraction 1.07 ± 0.52% → 6.1 ± 2.28% and prolonged a division-length metric 63.2 ± 23.9% (n=51) → 293.1 ± 145.5% (n=58) while slowing cyclin B degradation. (horakova2024earlyonsetof pages 8-11)
  • Spatial APC/C interaction measurements (2024, human cells, likely conserved): Cyclin B1–APC/C FCCS Kd ~80 nM (chromosomes) vs ~180 nM (cytoplasm). (cirillo2024spatialcontrolof pages 13-14)

Summary table

Aspect Key points Evidence type Key citation IDs
Function Cyclin B1 is the regulatory cyclin of CDK1/MPF driving G2/M transition and mitotic entry; promotes NEBD, chromosome condensation, spindle formation; in mouse oocytes, MPF reactivation after meiosis I particularly depends on Ccnb1 Mouse genetics, oocyte assay, review (chotiner2019functionsofcyclins pages 5-6, li2018cyclinb2can pages 1-2, li2018cyclinb2can pages 7-8, kim2023meioticcellcycle pages 3-5)
Biological process Required for proliferative divisions in embryos and mitotic germ cells; maternal CCNB1 can support first embryonic cleavages, but zygotic loss causes G2 arrest at ~4-cell stage in culture and embryonic death before E10; in male germline, needed for gonocyte/spermatogonial proliferation Mouse genetics, review (chotiner2019functionsofcyclins pages 5-6, tang2017requirementforccnb1 pages 1-2)
Localization Cyclin B1 is cytoplasmic in interphase and translocates to the nucleus at mitotic entry; localizes to microtubules/spindle and unattached kinetochores; distinguished from cyclin B2, which is more Golgi-associated Review, localization studies, conserved mechanistic evidence (kim2023meioticcellcycle pages 3-5, tang2017requirementforccnb1 pages 1-2, crncec2025plasticityofmitotic pages 18-19)
Checkpoint pathway role CDK1-CCNB1 creates a spindle-checkpoint-permissive state by enabling MPS1 kinetochore recruitment; CCNB1 decline sets the timing of checkpoint silencing and anaphase onset Conserved mechanistic study, review (li2019cyclinsregulatingoocyte pages 4-4, kim2023meioticcellcycle pages 3-5)
Regulation by APC/C APC/C with CDH1/FZR1 restrains CCNB1 accumulation during GV arrest; APC/C-CDC20 promotes cyclin B1 destruction at metaphase-anaphase and meiotic transitions; both Cyclin B1 and securin are key APC/C substrates Mouse oocyte assay, review (chen2022septin4controls pages 1-2, li2019cyclinsregulatingoocyte pages 4-4, li2018cyclinb2can pages 7-8)
Translational regulation Ccnb1 mRNA translation is strongly regulated during oocyte maturation by CPEB1 and 3'UTR architecture; short 3'UTR translation sets timing of meiotic re-entry, long 3'UTR supports MI→MII Cyclin B1 accumulation Mouse oocyte assay, gene-edited mouse study (han2017thetranslationof pages 2-3, wang2024alternativecleavageand pages 1-2, wang2024alternativecleavageand pages 10-12)
Quantitative recent data PAS1 ablation caused ~70% decrease in Cyclin B1 protein in GV oocytes; increased PAS1 usage produced ~2–3-fold more short-UTR Ccnb1 mRNA and accelerated meiotic re-entry; assays used 20 or 50 oocytes/lane with 3–4 biological replicates 2024 mouse primary study (wang2024alternativecleavageand pages 10-12)
Genetics: oocyte-specific deletion Gdf9-Cre Ccnb1 loss still allows GVBD and polar body extrusion because cyclin B2 compensates; however females are infertile because oocytes fail to sustain/restore MPF and enter premature interphase-like state in meiosis II; double Ccnb1/Ccnb2 loss arrests at GV Mouse genetics, oocyte assay (li2018cyclinb2can pages 1-2, li2018cyclinb2can pages 7-8)
Genetics: male germline Mvh/Ddx4-driven deletion depletes gonocytes/spermatogonia and causes sterility; later Stra8-Cre deletion has limited effect on spermatocyte meiosis/fertility, implying stage-specific requirement and redundancy in meiosis Mouse genetics (chotiner2019functionsofcyclins pages 5-6, tang2017requirementforccnb1 pages 1-2)
Genetics: granulosa cells Granulosa-cell Ccnb1 knockout causes subfertility; embryo development rates were reduced, with 2-cell embryos 39.2% vs 86.8%, morulae 26.0% vs 85.0%, blastocysts 19.1% vs 85.8%; 32.4% of oocytes showed abnormal chromosome condensation/spindle disassembly after PB1 extrusion 2022 mouse genetics (chen2022septin4controls pages 1-2)
Recent 2024 advance Spatial APC/C control: Cyclin B1 binds nucleosomes through an N-terminal arginine-anchor, concentrating Cyclin B1 with APC/C on the mitotic apparatus; disrupting chromatin binding delays degradation and causes aneuploidy; measured Cyclin B1-APC/C dissociation constants were ~80 nM on chromosomes vs ~180 nM in cytoplasm 2024 human cell mechanistic but likely conserved in vertebrates (cirillo2024spatialcontrolof pages 1-2, cirillo2024spatialcontrolof pages 9-10, cirillo2024spatialcontrolof pages 13-14, cirillo2024spatialcontrolof pages 2-4)
Recent 2024 advance Cyclin B1 can partner not only with CDK1 but also with CDK5 in mitosis, with co-IP evidence supporting a CDK5-cyclin B1 complex linked to mitotic fidelity 2024 mechanistic study (zheng2024cdk5cyclinb1regulates pages 1-4)
Embryo implementation/tool use Mouse embryo studies use fluorescent cyclin B1 reporters such as 90-cyB1 fragments fused to fluorophores, alongside securin and histone reporters, for live imaging of APC/C activity and mitotic timing; cRNAs injected at 2–4 ng/μL 2024 mouse embryo live-imaging study (horakova2024earlyonsetof pages 8-11)
Quantitative embryo dynamics In 2-cell embryos, nocodazole increased a measured abnormal fraction from 1.07 ± 0.52% to 6.1 ± 2.28% and prolonged division length from 63.2 ± 23.9% (n=51) to 293.1 ± 145.5% (n=58), while slowing cyclin B degradation 2024 mouse embryo live-imaging study (horakova2024earlyonsetof pages 8-11)

Table: This table summarizes core functional annotation for mouse Ccnb1/cyclin B1, including molecular function, pathways, localization, mouse genetics, and recent 2023-2024 advances. It also highlights quantitative findings and experimental tools useful for interpreting the gene’s biology.

References (URLs and publication dates)

Key sources used (all include DOI URLs):
- Cirillo et al., The EMBO Journal, Aug 2024. Spatial control of APC/C ensures rapid cyclin B1 degradation. https://doi.org/10.1038/s44318-024-00194-2 (cirillo2024spatialcontrolof pages 1-2)
- Zheng et al., Nature, Sep 2024. CDK5–cyclin B1 regulates mitotic fidelity. https://doi.org/10.1038/s41586-024-07888-x (zheng2024cdk5cyclinb1regulates pages 1-4)
- Wang et al., Nucleic Acids Research, Dec 2024. Ccnb1 mRNA APA defines cyclin protein accumulation in meiosis. https://doi.org/10.1093/nar/gkad1151 (wang2024alternativecleavageand pages 10-12)
- Horakova et al., Frontiers in Cell and Developmental Biology, Mar 2024. Early APC/C activity renders SAC inefficient in mouse embryos. https://doi.org/10.3389/fcell.2024.1355979 (horakova2024earlyonsetof pages 8-11)
- Kim et al., International Journal of Molecular Sciences, Sep 2023. Review: cyclins in mouse oocyte meiosis. https://doi.org/10.3390/ijms241713659 (kim2023meioticcellcycle pages 3-5)
- Chen et al., Journal of Cellular Physiology, Jun 2022. Septin4 controls CCNB1 stabilization via APC/C–CDC20 in mouse oocytes. https://doi.org/10.1002/jcp.30498 (chen2022septin4controls pages 1-2)
- Li et al., Journal of Cell Biology, Aug 2018. Cyclin B2 compensates for cyclin B1 in oocyte meiosis I. https://doi.org/10.1083/jcb.201802077 (li2018cyclinb2can pages 1-2)
- Tang et al., Cell Death & Disease, Oct 2017. Requirement for CCNB1 in mouse spermatogenesis. https://doi.org/10.1038/cddis.2017.555 (tang2017requirementforccnb1 pages 1-2)
- Chen et al., Cell Research, Feb 2008. Cyclin B1 localization to unattached kinetochores. https://doi.org/10.1038/cr.2008.11 (chen2008cyclinb1is pages 1-2)

References

  1. (chotiner2019functionsofcyclins pages 5-6): Jessica Y Chotiner, Debra J Wolgemuth, and P Jeremy Wang. Functions of cyclins and cdks in mammalian gametogenesis†. Biology of Reproduction, 101:591-601, Apr 2019. URL: https://doi.org/10.1093/biolre/ioz070, doi:10.1093/biolre/ioz070. This article has 77 citations and is from a peer-reviewed journal.

  2. (tang2017requirementforccnb1 pages 1-2): Ji-Xin Tang, Jian Li, Jin-Mei Cheng, Bian Hu, Tie-Cheng Sun, Xiao-Yu Li, Aalia Batool, Zhi-Peng Wang, Xiu-Xia Wang, Shou-Long Deng, Yan Zhang, Su-Ren Chen, Xingxu Huang, and Yi-Xun Liu. Requirement for ccnb1 in mouse spermatogenesis. Cell Death & Disease, 8:e3142-e3142, Oct 2017. URL: https://doi.org/10.1038/cddis.2017.555, doi:10.1038/cddis.2017.555. This article has 52 citations and is from a peer-reviewed journal.

  3. (chen2022septin4controls pages 1-2): Li Chen, Ying‐Chun Ouyang, Jian Li, Jing‐Yi Qiao, Lin ‐Jian Gu, Zhen‐Bo Wang, Yi Hou, Heide Schatten, and Qing‐Yuan Sun. Septin 4 controls ccnb1 stabilization via apc/ccdc20 during meiotic g2/m transition in mouse oocytes. Journal of Cellular Physiology, 237:730-742, Jun 2022. URL: https://doi.org/10.1002/jcp.30498, doi:10.1002/jcp.30498. This article has 7 citations and is from a peer-reviewed journal.

  4. (li2018cyclinb2can pages 7-8): Jian Li, Ji-Xin Tang, Jin-Mei Cheng, Bian Hu, Yu-Qian Wang, Batool Aalia, Xiao-Yu Li, Cheng Jin, Xiu-Xia Wang, Shou-Long Deng, Yan Zhang, Su-Ren Chen, Wei-Ping Qian, Qing-Yuan Sun, Xing-Xu Huang, and Yi-Xun Liu. Cyclin b2 can compensate for cyclin b1 in oocyte meiosis i. The Journal of Cell Biology, 217:3901-3911, Aug 2018. URL: https://doi.org/10.1083/jcb.201802077, doi:10.1083/jcb.201802077. This article has 81 citations.

  5. (chen2008cyclinb1is pages 1-2): Qiang Chen, Xiaoyan Zhang, Qing Jiang, Paul R Clarke, and Chuanmao Zhang. Cyclin b1 is localized to unattached kinetochores and contributes to efficient microtubule attachment and proper chromosome alignment during mitosis. Cell Research, 18:268-280, Feb 2008. URL: https://doi.org/10.1038/cr.2008.11, doi:10.1038/cr.2008.11. This article has 124 citations and is from a domain leading peer-reviewed journal.

  6. (chen2008cyclinb1is pages 4-5): Qiang Chen, Xiaoyan Zhang, Qing Jiang, Paul R Clarke, and Chuanmao Zhang. Cyclin b1 is localized to unattached kinetochores and contributes to efficient microtubule attachment and proper chromosome alignment during mitosis. Cell Research, 18:268-280, Feb 2008. URL: https://doi.org/10.1038/cr.2008.11, doi:10.1038/cr.2008.11. This article has 124 citations and is from a domain leading peer-reviewed journal.

  7. (li2019cyclinsregulatingoocyte pages 4-4): Jian Li, Wei-Ping Qian, and Qing-Yuan Sun. Cyclins regulating oocyte meiotic cell cycle progression†. Biology of Reproduction, 101:878-881, Jul 2019. URL: https://doi.org/10.1093/biolre/ioz143, doi:10.1093/biolre/ioz143. This article has 88 citations and is from a peer-reviewed journal.

  8. (horakova2024earlyonsetof pages 8-11): Adela Horakova, Marketa Konecna, Lenka Radonova, and Martin Anger. Early onset of apc/c activity renders sac inefficient in mouse embryos. Frontiers in Cell and Developmental Biology, Mar 2024. URL: https://doi.org/10.3389/fcell.2024.1355979, doi:10.3389/fcell.2024.1355979. This article has 1 citations.

  9. (chen2008cyclinb1is pages 10-11): Qiang Chen, Xiaoyan Zhang, Qing Jiang, Paul R Clarke, and Chuanmao Zhang. Cyclin b1 is localized to unattached kinetochores and contributes to efficient microtubule attachment and proper chromosome alignment during mitosis. Cell Research, 18:268-280, Feb 2008. URL: https://doi.org/10.1038/cr.2008.11, doi:10.1038/cr.2008.11. This article has 124 citations and is from a domain leading peer-reviewed journal.

  10. (bentley2007distinctsequenceelements pages 6-7): Anna M. Bentley, Guillaume Normand, Jonathan Hoyt, and Randall W. King. Distinct sequence elements of cyclin b1 promote localization to chromatin, centrosomes, and kinetochores during mitosis. Molecular biology of the cell, 18 12:4847-58, Dec 2007. URL: https://doi.org/10.1091/mbc.e06-06-0539, doi:10.1091/mbc.e06-06-0539. This article has 104 citations and is from a domain leading peer-reviewed journal.

  11. (li2018cyclinb2can pages 1-2): Jian Li, Ji-Xin Tang, Jin-Mei Cheng, Bian Hu, Yu-Qian Wang, Batool Aalia, Xiao-Yu Li, Cheng Jin, Xiu-Xia Wang, Shou-Long Deng, Yan Zhang, Su-Ren Chen, Wei-Ping Qian, Qing-Yuan Sun, Xing-Xu Huang, and Yi-Xun Liu. Cyclin b2 can compensate for cyclin b1 in oocyte meiosis i. The Journal of Cell Biology, 217:3901-3911, Aug 2018. URL: https://doi.org/10.1083/jcb.201802077, doi:10.1083/jcb.201802077. This article has 81 citations.

  12. (cirillo2024spatialcontrolof pages 13-14): Luca Cirillo, Rose Young, Sapthaswaran Veerapathiran, Annalisa Roberti, Molly Martin, Azzah Abubacar, Camilla Perosa, Catherine Coates, Reyhan Muhammad, Theodoros I Roumeliotis, Jyoti S Choudhary, Claudio Alfieri, and Jonathon Pines. Spatial control of the apc/c ensures the rapid degradation of cyclin b1. The EMBO Journal, 43:4324-4355, Aug 2024. URL: https://doi.org/10.1038/s44318-024-00194-2, doi:10.1038/s44318-024-00194-2. This article has 19 citations.

  13. (cirillo2024spatialcontrolof pages 9-10): Luca Cirillo, Rose Young, Sapthaswaran Veerapathiran, Annalisa Roberti, Molly Martin, Azzah Abubacar, Camilla Perosa, Catherine Coates, Reyhan Muhammad, Theodoros I Roumeliotis, Jyoti S Choudhary, Claudio Alfieri, and Jonathon Pines. Spatial control of the apc/c ensures the rapid degradation of cyclin b1. The EMBO Journal, 43:4324-4355, Aug 2024. URL: https://doi.org/10.1038/s44318-024-00194-2, doi:10.1038/s44318-024-00194-2. This article has 19 citations.

  14. (cirillo2024spatialcontrolof pages 4-6): Luca Cirillo, Rose Young, Sapthaswaran Veerapathiran, Annalisa Roberti, Molly Martin, Azzah Abubacar, Camilla Perosa, Catherine Coates, Reyhan Muhammad, Theodoros I Roumeliotis, Jyoti S Choudhary, Claudio Alfieri, and Jonathon Pines. Spatial control of the apc/c ensures the rapid degradation of cyclin b1. The EMBO Journal, 43:4324-4355, Aug 2024. URL: https://doi.org/10.1038/s44318-024-00194-2, doi:10.1038/s44318-024-00194-2. This article has 19 citations.

  15. (cirillo2024spatialcontrolof pages 1-2): Luca Cirillo, Rose Young, Sapthaswaran Veerapathiran, Annalisa Roberti, Molly Martin, Azzah Abubacar, Camilla Perosa, Catherine Coates, Reyhan Muhammad, Theodoros I Roumeliotis, Jyoti S Choudhary, Claudio Alfieri, and Jonathon Pines. Spatial control of the apc/c ensures the rapid degradation of cyclin b1. The EMBO Journal, 43:4324-4355, Aug 2024. URL: https://doi.org/10.1038/s44318-024-00194-2, doi:10.1038/s44318-024-00194-2. This article has 19 citations.

  16. (zheng2024cdk5cyclinb1regulates pages 1-4): Xiao-Feng Zheng, Aniruddha Sarkar, Humphrey Lotana, Aleem Syed, Huy Nguyen, Richard G. Ivey, Jacob J. Kennedy, Jeffrey R. Whiteaker, Bartłomiej Tomasik, Kaimeng Huang, Feng Li, Alan D. D’Andrea, Amanda G. Paulovich, Kavita Shah, Alexander Spektor, and Dipanjan Chowdhury. Cdk5-cyclin b1 regulates mitotic fidelity. Nature, 633:932-940, Sep 2024. URL: https://doi.org/10.1038/s41586-024-07888-x, doi:10.1038/s41586-024-07888-x. This article has 23 citations and is from a highest quality peer-reviewed journal.

  17. (wang2024alternativecleavageand pages 10-12): Xiaotian Wang, Fang-Shiuan Leung, Jeffrey O Bush, and Marco Conti. Alternative cleavage and polyadenylation of the ccnb1 mrna defines accumulation of cyclin protein during the meiotic cell cycle. Nucleic Acids Research, 52:1258-1271, Dec 2024. URL: https://doi.org/10.1093/nar/gkad1151, doi:10.1093/nar/gkad1151. This article has 4 citations and is from a highest quality peer-reviewed journal.

  18. (kim2023meioticcellcycle pages 3-5): Hye Min Kim, Min Kook Kang, Se Yoon Seong, Jun Hyeon Jo, Min Ju Kim, Eun Kyeong Shin, Chang Geun Lee, and Seung Jin Han. Meiotic cell cycle progression in mouse oocytes: role of cyclins. International Journal of Molecular Sciences, 24:13659, Sep 2023. URL: https://doi.org/10.3390/ijms241713659, doi:10.3390/ijms241713659. This article has 11 citations.

  19. (crncec2025plasticityofmitotic pages 18-19): Adrijana Crncec, Ho Wai Lau, Lau Yan Ng, Hoi Tang Ma, Joyce P.Y. Mak, Hon Fung Choi, Tsz Kwan Yeung, and Randy Yat Choi Poon. Plasticity of mitotic cyclins in promoting the g2–m transition. The Journal of Cell Biology, Apr 2025. URL: https://doi.org/10.1083/jcb.202409219, doi:10.1083/jcb.202409219. This article has 5 citations.

  20. (han2017thetranslationof pages 2-3): Seung Jin Han, João Pedro Sousa Martins, Ye Yang, Min Kook Kang, Enrico Maria Daldello, and Marco Conti. The translation of cyclin b1 and b2 is differentially regulated during mouse oocyte reentry into the meiotic cell cycle. Scientific Reports, Oct 2017. URL: https://doi.org/10.1038/s41598-017-13688-3, doi:10.1038/s41598-017-13688-3. This article has 65 citations and is from a peer-reviewed journal.

  21. (wang2024alternativecleavageand pages 1-2): Xiaotian Wang, Fang-Shiuan Leung, Jeffrey O Bush, and Marco Conti. Alternative cleavage and polyadenylation of the ccnb1 mrna defines accumulation of cyclin protein during the meiotic cell cycle. Nucleic Acids Research, 52:1258-1271, Dec 2024. URL: https://doi.org/10.1093/nar/gkad1151, doi:10.1093/nar/gkad1151. This article has 4 citations and is from a highest quality peer-reviewed journal.

  22. (cirillo2024spatialcontrolof pages 2-4): Luca Cirillo, Rose Young, Sapthaswaran Veerapathiran, Annalisa Roberti, Molly Martin, Azzah Abubacar, Camilla Perosa, Catherine Coates, Reyhan Muhammad, Theodoros I Roumeliotis, Jyoti S Choudhary, Claudio Alfieri, and Jonathon Pines. Spatial control of the apc/c ensures the rapid degradation of cyclin b1. The EMBO Journal, 43:4324-4355, Aug 2024. URL: https://doi.org/10.1038/s44318-024-00194-2, doi:10.1038/s44318-024-00194-2. This article has 19 citations.

Citations

  1. li2019cyclinsregulatingoocyte pages 4-4
  2. horakova2024earlyonsetof pages 8-11
  3. chotiner2019functionsofcyclins pages 5-6
  4. cirillo2024spatialcontrolof pages 1-2
  5. wang2024alternativecleavageand pages 10-12
  6. kim2023meioticcellcycle pages 3-5
  7. cirillo2024spatialcontrolof pages 13-14
  8. bentley2007distinctsequenceelements pages 6-7
  9. cirillo2024spatialcontrolof pages 9-10
  10. cirillo2024spatialcontrolof pages 4-6
  11. crncec2025plasticityofmitotic pages 18-19
  12. han2017thetranslationof pages 2-3
  13. wang2024alternativecleavageand pages 1-2
  14. cirillo2024spatialcontrolof pages 2-4
  15. https://doi.org/10.1038/s44318-024-00194-2
  16. https://doi.org/10.1038/s41586-024-07888-x
  17. https://doi.org/10.1093/nar/gkad1151
  18. https://doi.org/10.3389/fcell.2024.1355979
  19. https://doi.org/10.3390/ijms241713659
  20. https://doi.org/10.1002/jcp.30498
  21. https://doi.org/10.1083/jcb.201802077
  22. https://doi.org/10.1038/cddis.2017.555
  23. https://doi.org/10.1038/cr.2008.11
  24. https://doi.org/10.1093/biolre/ioz070,
  25. https://doi.org/10.1038/cddis.2017.555,
  26. https://doi.org/10.1002/jcp.30498,
  27. https://doi.org/10.1083/jcb.201802077,
  28. https://doi.org/10.1038/cr.2008.11,
  29. https://doi.org/10.1093/biolre/ioz143,
  30. https://doi.org/10.3389/fcell.2024.1355979,
  31. https://doi.org/10.1091/mbc.e06-06-0539,
  32. https://doi.org/10.1038/s44318-024-00194-2,
  33. https://doi.org/10.1038/s41586-024-07888-x,
  34. https://doi.org/10.1093/nar/gkad1151,
  35. https://doi.org/10.3390/ijms241713659,
  36. https://doi.org/10.1083/jcb.202409219,
  37. https://doi.org/10.1038/s41598-017-13688-3,

📄 View Raw YAML

id: P24860
gene_symbol: Ccnb1
product_type: PROTEIN
status: COMPLETE
description: 'Cyclin B1 is the non-catalytic regulatory cyclin that binds and activates CDK1
  in the cyclin B1-CDK1 complex to drive mitotic entry and progression through G2/M. Its abundance
  and localization are tightly cell-cycle regulated, with cytoplasmic accumulation followed
  by nuclear and centrosomal/spindle-associated pools during mitosis. The cyclin B1-CDK1 complex
  phosphorylates mitotic substrates and also has a non-core mitochondrial pool that coordinates
  respiration with G2/M progression. Ccnb1 is essential for embryonic development, while many
  tissue-specific proliferation phenotypes are downstream consequences of its core cell-cycle
  role.'
taxon:
  id: NCBITaxon:10090
  label: Mus musculus
existing_annotations:
- term:
    id: GO:0000082
    label: G1/S transition of mitotic cell cycle
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: The existing annotation captures cell-cycle or phosphorylation biology but
      uses an inaccurate or overly broad term for cyclin B1.
    action: MODIFY
    reason: The source term says negative regulation of protein phosphorylation, but cyclin
      B1 promotes mitotic entry through the cyclin B1-CDK1 complex. The replacement keeps
      this as a biological-process correction focused on G2/M transition rather than as a
      molecular-function claim about CDK activation.
    proposed_replacement_terms:
    - id: GO:0010971
      label: positive regulation of G2/M transition of mitotic cell cycle
    supported_by:
    - reference_id: file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
      supporting_text: Cyclin B1 is the major regulatory partner of CDK1, forming the
        CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis
        entry.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: PMID:17325031 supports cyclin B1 accumulation in metaphase-arrested embryos,
      but the cached abstract does not directly establish nuclear localization.
    action: UNDECIDED
    reason: Cyclin B1 nuclear localization is biologically plausible, but this evidence row
      needs direct localization support from the full text or another source before acceptance.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: PMID:17325031 supports cyclin B1 accumulation in metaphase-arrested embryos,
      but the cached abstract does not directly establish cytoplasmic localization.
    action: UNDECIDED
    reason: Cyclin B1 cytoplasmic localization is biologically plausible, but this evidence row
      needs direct localization support from the full text or another source before acceptance.
- term:
    id: GO:0016538
    label: cyclin-dependent protein serine/threonine kinase regulator activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: The existing annotation captures cell-cycle or phosphorylation biology but
      uses an inaccurate or overly broad term for cyclin B1.
    action: MODIFY
    reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the
      replacement term better represents the supported G2/M or CDK-activation role.
    proposed_replacement_terms:
    - id: GO:0061575
      label: cyclin-dependent protein serine/threonine kinase activator activity
    supported_by:
    - reference_id: file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
      supporting_text: Cyclin B1's primary molecular role is to activate and localize
        CDK1 kinase activity to initiate and orchestrate M-phase events.
- term:
    id: GO:0005815
    label: microtubule organizing center
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0097125
    label: cyclin B1-CDK1 complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
    supported_by:
    - reference_id: file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
      supporting_text: Cyclin B1 is the major regulatory partner of CDK1, forming the
        CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis
        entry.
- term:
    id: GO:0007080
    label: mitotic metaphase chromosome alignment
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
    supported_by:
    - reference_id: file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
      supporting_text: Cyclin B1 localizes to unattached kinetochores and contributes
        to efficient microtubule attachment and proper chromosome alignment during
        mitosis.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0005813
    label: centrosome
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0016538
    label: cyclin-dependent protein serine/threonine kinase regulator activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: The existing annotation captures cell-cycle or phosphorylation biology but
      uses an inaccurate or overly broad term for cyclin B1.
    action: MODIFY
    reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the
      replacement term better represents the supported G2/M or CDK-activation role.
    proposed_replacement_terms:
    - id: GO:0061575
      label: cyclin-dependent protein serine/threonine kinase activator activity
- term:
    id: GO:0044772
    label: mitotic cell cycle phase transition
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0051301
    label: cell division
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0000922
    label: spindle pole
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0000940
    label: outer kinetochore
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0001556
    label: oocyte maturation
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0005113
    label: patched binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0007052
    label: mitotic spindle organization
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0007080
    label: mitotic metaphase chromosome alignment
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0007283
    label: spermatogenesis
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0009410
    label: response to xenobiotic stimulus
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0009612
    label: response to mechanical stimulus
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0009636
    label: response to toxic substance
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0010629
    label: negative regulation of gene expression
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0010971
    label: positive regulation of G2/M transition of mitotic cell cycle
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0019901
    label: protein kinase binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0031442
    label: positive regulation of mRNA 3'-end processing
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0042246
    label: tissue regeneration
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0044389
    label: ubiquitin-like protein ligase binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0045931
    label: positive regulation of mitotic cell cycle
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0046680
    label: response to DDT
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0048565
    label: digestive tract development
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0051987
    label: positive regulation of attachment of spindle microtubules to kinetochore
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0055015
    label: ventricular cardiac muscle cell development
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0060045
    label: positive regulation of cardiac muscle cell proliferation
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0060623
    label: regulation of chromosome condensation
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0061575
    label: cyclin-dependent protein serine/threonine kinase activator activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0065003
    label: protein-containing complex assembly
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0071283
    label: cellular response to iron(III) ion
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0071398
    label: cellular response to fatty acid
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0071456
    label: cellular response to hypoxia
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0090266
    label: regulation of mitotic cell cycle spindle assembly checkpoint
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0097125
    label: cyclin B1-CDK1 complex
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:1905448
    label: positive regulation of mitochondrial ATP synthesis coupled electron transport
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0001933
    label: negative regulation of protein phosphorylation
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: The existing annotation captures cell-cycle or phosphorylation biology but
      uses an inaccurate or overly broad term for cyclin B1.
    action: MODIFY
    reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the
      replacement term better represents the supported G2/M or CDK-activation role.
    proposed_replacement_terms:
    - id: GO:0010971
      label: positive regulation of G2/M transition of mitotic cell cycle
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0045860
    label: positive regulation of protein kinase activity
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0000922
    label: spindle pole
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0000940
    label: outer kinetochore
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0001556
    label: oocyte maturation
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0005113
    label: patched binding
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0005813
    label: centrosome
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0007052
    label: mitotic spindle organization
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0007080
    label: mitotic metaphase chromosome alignment
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0010629
    label: negative regulation of gene expression
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0010971
    label: positive regulation of G2/M transition of mitotic cell cycle
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0019901
    label: protein kinase binding
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0019901
    label: protein kinase binding
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0031442
    label: positive regulation of mRNA 3'-end processing
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
- term:
    id: GO:0044389
    label: ubiquitin-like protein ligase binding
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0044877
    label: protein-containing complex binding
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: The existing annotation captures cell-cycle or phosphorylation biology but
      uses an inaccurate or overly broad term for cyclin B1.
    action: MODIFY
    reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the
      replacement term better represents the supported G2/M or CDK-activation role.
    proposed_replacement_terms:
    - id: GO:0061575
      label: cyclin-dependent protein serine/threonine kinase activator activity
- term:
    id: GO:0045931
    label: positive regulation of mitotic cell cycle
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0051987
    label: positive regulation of attachment of spindle microtubules to kinetochore
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0060045
    label: positive regulation of cardiac muscle cell proliferation
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0060623
    label: regulation of chromosome condensation
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0061575
    label: cyclin-dependent protein serine/threonine kinase activator activity
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0065003
    label: protein-containing complex assembly
  evidence_type: ISO
  original_reference_id: GO_REF:0000096
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0090266
    label: regulation of mitotic cell cycle spindle assembly checkpoint
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0097125
    label: cyclin B1-CDK1 complex
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:1905448
    label: positive regulation of mitochondrial ATP synthesis coupled electron transport
  evidence_type: ISO
  original_reference_id: GO_REF:0000119
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12124778
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
    supported_by:
    - reference_id: PMID:12124778
      supporting_text: GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with a
        role in S and G2/M cell cycle checkpoints induced by genotoxic stress.
- term:
    id: GO:0005759
    label: mitochondrial matrix
  evidence_type: IDA
  original_reference_id: PMID:24746669
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
    supported_by:
    - reference_id: PMID:24746669
      supporting_text: Cyclin B1/Cdk1 coordinates mitochondrial respiration for
        cell-cycle G2/M progression.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:17325031
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
    supported_by:
    - reference_id: PMID:17325031
      supporting_text: Loss of Cdc20 causes a securin-dependent metaphase arrest in
        two-cell mouse embryos.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IDA
  original_reference_id: PMID:17325031
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
    supported_by:
    - reference_id: PMID:17325031
      supporting_text: Loss of Cdc20 causes a securin-dependent metaphase arrest in
        two-cell mouse embryos.
- term:
    id: GO:0045787
    label: positive regulation of cell cycle
  evidence_type: IDA
  original_reference_id: PMID:22053081
  review:
    summary: The existing annotation captures cell-cycle or phosphorylation biology but
      uses an inaccurate or overly broad term for cyclin B1.
    action: MODIFY
    reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the
      replacement term better represents the supported G2/M or CDK-activation role.
    proposed_replacement_terms:
    - id: GO:0010971
      label: positive regulation of G2/M transition of mitotic cell cycle
    supported_by:
    - reference_id: PMID:22053081
      supporting_text: Upregulation of Cyclin B1 by miRNA and its implications in
        cancer.
- term:
    id: GO:0048146
    label: positive regulation of fibroblast proliferation
  evidence_type: IMP
  original_reference_id: PMID:22053081
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
    supported_by:
    - reference_id: PMID:22053081
      supporting_text: Upregulation of Cyclin B1 by miRNA and its implications in
        cancer.
- term:
    id: GO:0016020
    label: membrane
  evidence_type: IDA
  original_reference_id: PMID:9539739
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
    supported_by:
    - reference_id: PMID:9539739
      supporting_text: Cyclin B2-null mice develop normally and are fertile whereas
        cyclin B1-null mice die in utero.
- term:
    id: GO:0005813
    label: centrosome
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:19376971
  review:
    summary: The cited Filia paper does not support Ccnb1 nuclear localization.
    action: REMOVE
    reason: PMID:19376971 describes Filia effects on spindle assembly and checkpoint
      regulators in embryos, not cyclin B1 localization. Cyclin B1 nuclear localization
      is supported elsewhere, but this evidence assertion should not be retained.
    supported_by:
    - reference_id: PMID:19376971
      supporting_text: Role of Filia, a maternal effect gene, in maintaining euploidy
        during cleavage-stage mouse embryogenesis.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:16489008
  review:
    summary: Supported core cyclin B1/CDK1 mitotic function or a well-established
      mitotic localization.
    action: ACCEPT
    reason: This term is consistent with cyclin B1 as the regulatory subunit of the
      cyclin B1-CDK1 complex that drives G2/M and mitotic progression.
    supported_by:
    - reference_id: PMID:16489008
      supporting_text: Patched1 functions as a gatekeeper by promoting cell cycle
        progression.
- term:
    id: GO:0001701
    label: in utero embryonic development
  evidence_type: IMP
  original_reference_id: PMID:9539739
  review:
    summary: Supported but context-specific or downstream cyclin B1 biology.
    action: KEEP_AS_NON_CORE
    reason: The annotation is compatible with the literature, but it reflects a
      localization, interaction, developmental consequence, or noncanonical
      mitochondrial role rather than the primary CDK1-activation function.
    supported_by:
    - reference_id: PMID:9539739
      supporting_text: Cyclin B2-null mice develop normally and are fertile whereas
        cyclin B1-null mice die in utero.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: ISO
  original_reference_id: PMID:16109376
  review:
    summary: The cited P-TEFb paper does not support Ccnb1 nuclear localization.
    action: REMOVE
    reason: PMID:16109376 is about Brd4/P-TEFb, cyclin T1, and CDK9 biology, not
      Ccnb1/cyclin B1 localization. Cyclin B1 nuclear localization is supported elsewhere,
      but this evidence assertion should not be retained.
    supported_by:
    - reference_id: PMID:16109376
      supporting_text: The bromodomain protein Brd4 is a positive regulatory component
        of P-TEFb and stimulates RNA polymerase II-dependent transcription.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:14993286
  review:
    summary: The cited cyclin F paper does not support Ccnb1 nuclear localization.
    action: REMOVE
    reason: PMID:14993286 describes cyclin F disruption and related cell-cycle defects,
      not Ccnb1/cyclin B1 localization. Cyclin B1 nuclear localization is supported
      elsewhere, but this evidence assertion should not be retained.
    supported_by:
    - reference_id: PMID:14993286
      supporting_text: Cyclin F disruption compromises placental development and affects
        normal cell cycle execution.
- term:
    id: GO:0006468
    label: protein phosphorylation
  evidence_type: IDA
  original_reference_id: PMID:12124778
  review:
    summary: The existing annotation captures cell-cycle or phosphorylation biology but
      uses an inaccurate or overly broad term for cyclin B1.
    action: MODIFY
    reason: Cyclin B1 is a non-catalytic CDK1 regulatory/activating cyclin; the
      replacement term better represents the supported G2/M or CDK-activation role.
    proposed_replacement_terms:
    - id: GO:0061575
      label: cyclin-dependent protein serine/threonine kinase activator activity
    supported_by:
    - reference_id: PMID:12124778
      supporting_text: GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with a
        role in S and G2/M cell cycle checkpoints induced by genotoxic stress.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12525704
  review:
    summary: The term is weakly informative or extrapolated relative to the core
      evidence.
    action: MARK_AS_OVER_ANNOTATED
    reason: This annotation is not the best representation of cyclin B1 function and
      likely reflects a broad computational transfer, stress-expression correlation, or
      vague binding term.
    supported_by:
    - reference_id: PMID:12525704
      supporting_text: RFPL4 interacts with oocyte proteins of the ubiquitin-proteasome
        degradation pathway.
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000024
  title: Manual transfer of experimentally-verified manual GO annotation data to
    orthologs by curator judgment of sequence similarity
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000043
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
  findings: []
- id: GO_REF:0000096
  title: Automated transfer of experimentally-verified manual GO annotation data to
    mouse-rat orthologs
  findings: []
- id: GO_REF:0000107
  title: Automatic transfer of experimentally verified manual GO annotation data to
    orthologs using Ensembl Compara
  findings: []
- id: GO_REF:0000119
  title: Automated transfer of experimentally-verified manual GO annotation data to
    mouse-human orthologs
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:12124778
  title: GADD45b and GADD45g are cdc2/cyclinB1 kinase inhibitors with a role in S and
    G2/M cell cycle checkpoints induced by genotoxic stress.
  findings: []
- id: PMID:12525704
  title: RFPL4 interacts with oocyte proteins of the ubiquitin-proteasome degradation
    pathway.
  findings: []
- id: PMID:14993286
  title: Cyclin F disruption compromises placental development and affects normal cell
    cycle execution.
  findings: []
- id: PMID:16109376
  title: The bromodomain protein Brd4 is a positive regulatory component of P-TEFb and
    stimulates RNA polymerase II-dependent transcription.
  findings: []
- id: PMID:16489008
  title: Patched1 functions as a gatekeeper by promoting cell cycle progression.
  findings: []
- id: PMID:17325031
  title: Loss of Cdc20 causes a securin-dependent metaphase arrest in two-cell mouse
    embryos.
  findings: []
- id: PMID:19376971
  title: Role of Filia, a maternal effect gene, in maintaining euploidy during
    cleavage-stage mouse embryogenesis.
  findings: []
- id: PMID:22053081
  title: Upregulation of Cyclin B1 by miRNA and its implications in cancer.
  findings: []
- id: PMID:24746669
  title: Cyclin B1/Cdk1 coordinates mitochondrial respiration for cell-cycle G2/M
    progression.
  findings: []
- id: PMID:9539739
  title: Cyclin B2-null mice develop normally and are fertile whereas cyclin B1-null
    mice die in utero.
  findings: []
- id: file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
  title: Falcon deep research synthesis for mouse Ccnb1
  findings:
  - statement: Cyclin B1 is the major CDK1 regulatory cyclin driving G2/M transition
      and mitotic entry, with dynamic cytoplasmic, nuclear, centrosomal, spindle, and
      kinetochore localization.
    supporting_text: Cyclin B1 is the major regulatory partner of CDK1, forming the
      CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis
      entry, including nuclear envelope breakdown (NEBD) and spindle formation.
core_functions:
- description: Cyclin B1 activates and targets CDK1 in the cyclin B1-CDK1 complex to
    drive G2/M transition and mitotic progression.
  molecular_function:
    id: GO:0061575
    label: cyclin-dependent protein serine/threonine kinase activator activity
  directly_involved_in:
  - id: GO:0010971
    label: positive regulation of G2/M transition of mitotic cell cycle
  - id: GO:0044772
    label: mitotic cell cycle phase transition
  locations:
  - id: GO:0005634
    label: nucleus
  - id: GO:0005737
    label: cytoplasm
  - id: GO:0005813
    label: centrosome
  in_complex:
    id: GO:0097125
    label: cyclin B1-CDK1 complex
  supported_by:
  - reference_id: file:mouse/Ccnb1/Ccnb1-uniprot.txt
    supporting_text: Essential for the control of the cell cycle at the G2/M
  - reference_id: file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
    supporting_text: Cyclin B1 is the major regulatory partner of CDK1, forming the
      CDK1-cyclin B1 complex (MPF) that drives the G2/M transition and mitotic/meiosis
      entry, including nuclear envelope breakdown (NEBD) and spindle formation.
  - reference_id: file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
    supporting_text: Cyclin B1 accumulates in S/G2 and shuttles cytoplasm to nucleus,
      becoming concentrated in the nucleus at late G2/prophase. During prometaphase it
      localizes to centrosomes, mitotic spindle, chromosome arms, and unattached
      kinetochores.