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 minor 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 cell-cycle-transition biology is real, but this term names the G1/S transition, which is driven by the D- and E-type cyclins that seed the node, not by the mitotic B-type cyclin B1.
Reason: The IBD behind this row sits at PANTHER node PTN000019791 near the base of the CYCLINS family, and every seed this review identified for this term is a G1/S or S-phase cyclin - mouse Ccnd1 (MGI:88313), rat Ccnd3/Ccnd2 (RGD:2293, RGD:621083), human CCND1/CCND2/CCNE1 (P24385, P30279, P24864), fly CycE, worm cyd-1/cye-1 and budding-yeast CLN3/CLB5/CLB6. Neither mouse Ccnb1 nor human CCNB1 (P14635) is among them. Cyclin B1 is the mitotic cyclin that activates CDK1 at G2/M, so the phase named by the term is wrong even though the cell-cycle-transition role is right.
Propagation Review
Root cause: TERM SCOPING PROBLEM
Failure modes: WRONG ORTHOLOG OR PARALOG
Sources checked:
PANTHER:PTN000019791 · deep ancestral node of PANTHER family PTHR10177 (CYCLINS) SUPPORTS SOURCE BUT NOT TARGET
A very deep, broadly seeded node spanning animal, fungal, plant and trypanosome cyclins of all classes (A, B, D, E, F, G, O, T). The ancient cyclin-box/CDK-partner role is well supported at this depth, but a phase-specific term such as G1/S transition is not a property of the node as a whole and should not follow descent from it onto a mitotic cyclin.
MGI:MGI:88313 · mouse Ccnd1 (cyclin D1) SUPPORTS SOURCE BUT NOT TARGET
A G1 D-type cyclin partnering CDK4/6; its G1/S transition evidence is sound for itself but does not describe cyclin B1. Symbol corroborated via the family index: PTHR10177-entries.csv gives UniProtKB:P25322 the gene Ccnd1, "G1/S-specific cyclin-D1", in Mus musculus.
UniProtKB:P24864 · human CCNE1 (G1/S-specific cyclin-E1) SUPPORTS SOURCE BUT NOT TARGET
The canonical G1/S cyclin-E; its CDK2-dependent G1/S role is the biology this term was placed for.
SGD:S000006324 · budding-yeast CLB5 SUPPORTS SOURCE BUT NOT TARGET
An S-phase-promoting B-type cyclin; together with CLB6 and CLN3 it makes the seed set uniformly G1/S-S-phase rather than mitotic. Symbol resolved rather than assumed: the SGD id maps to UniProtKB:P30283, which PTHR10177-entries.csv gives the gene CLB5, "S-phase entry cyclin-5", in S. cerevisiae. Only the SGD-to-UniProt step needs an external lookup - the symbol itself is in the family index, but nothing local links it to this SGD identifier.
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
ACCEPT
Summary: Cyclin B1 shuttles between cytoplasm and nucleus and becomes nuclear at mitotic entry, and mouse Ccnb1's own experimental nuclear localization is one of the descendant evidences behind this node, so the inherited nuclear pool is well grounded.
Reason: The IBD behind this row sits at PANTHER node PTN000019791 in PTHR10177 (CYCLINS), and its seed set for nucleus is broad and deep - fly, fission-yeast, budding-yeast, Arabidopsis and several mammalian cyclins - which places a nuclear pool at an ancestral node of the cyclin-box CDK partners rather than in one lineage. Mouse Ccnb1 (MGI:88302) is itself among those seeds, because its own IDA nucleus annotation is part of the evidence the PAINT curator weighed, and there is no target-specific evidence of divergence. Cyclin B1 concentrates in the nucleus at late G2/prophase, where cyclin B1-CDK1 drives nuclear envelope breakdown. Nucleus is a broad compartment, but breadth alone is not grounds for doubt when the specific biology is established - nucleus is already one of this review's core-function locations. The sibling nucleus rows are not uniformly accepted - the IEA and ISO GO_REF rows and two IDAs (PMID:17325031, PMID:16489008) are accepted, two further IDAs (PMID:19376971, PMID:14993286) are UNDECIDED, and one ISO (PMID:16109376) is REMOVEd for citing a P-TEFb paper. That split is inherited and is NOT adjudicated here, because nothing in this repository separates the two pairs - all four IDA caches are flagged full_text_available false, and all four supporting_text values are the cited paper's own title. Any criterion that would distinguish them - abstract-only status included - applies equally to both sides. The ACCEPT on this IBA row does not rest on that split; it rests on the node argument above, the absence of target-specific divergence, and the established late-G2/prophase nuclear pool.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
PANTHER:PTN000019791 · ancestral node of PANTHER family PTHR10177 (CYCLINS) SUPPORTS TRANSFER
The nucleus IBD sits at this deep cyclin node, and its seed set for the term reaches across fly, fission-yeast, budding-yeast, Arabidopsis and mammalian cyclins. That breadth places a nuclear pool at the base of the cyclin-box CDK partners rather than in one lineage, so descent from the node is a sound basis for the compartment in mouse Ccnb1.
MGI:MGI:88302 · mouse Ccnb1 (this gene) SUPPORTS TRANSFER
The target's own IBD seed. Mouse Ccnb1 carries experimental nucleus IDAs in GOA, among the descendant evidences the PAINT curator weighed when placing this node, so its appearance here marks node membership with experimental support behind it. Scope of that claim, since the retained-grounding rule turns on what this review can stand behind: it defers to the curator, who read the full texts. It is NOT corroborated here - both retained IDA rows (PMID:17325031, PMID:16489008) have abstract-only caches and quote only the papers' titles, so this review cannot show what those assays observed.
MGI:MGI:88316 · mouse Ccne1 (cyclin E1) SUPPORTS TRANSFER
A second mammalian cyclin seed at the same node, from a different cyclin class, indicating the nuclear compartment is shared across the classes the node spans rather than being specific to one of them. Symbol resolved from the MOD id itself (Ccne1-uniprot.txt cross-references MGI:88316 to Ccne1).
PomBase:SPBC582.03 SUPPORTS TRANSFER
Fission-yeast seed at the same node, cited by identifier because the local index does not resolve it. It is part of the fungal coverage that makes the nuclear pool an ancient rather than a vertebrate-specific property.
Supporting Evidence:
file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
Cyclin B1 is spatially regulated: it shuttles between cytoplasm and nucleus and becomes nuclear at mitotic entry
GO:0005737 cytoplasm
IBA
GO_REF:0000033
ACCEPT
Summary: Cyclin B1 accumulates in the cytoplasm through S and G2 before its mitotic nuclear translocation, and mouse Ccnb1's own experimental cytoplasmic localization is one of the descendant evidences behind this node.
Reason: The IBD sits at PANTHER node PTN000019791 in PTHR10177 (CYCLINS), whose seed set for cytoplasm spans plant, fungal, fly and mammalian cyclins, so a cytoplasmic pool is an ancestral property of the family rather than a single-organism finding. Mouse Ccnb1 (MGI:88302) is one of those seeds and carries its own IDA cytoplasm annotation, and nothing target-specific argues against inheritance. Cytoplasm is a broad subsuming compartment - it contains the centrosomal, spindle and mitochondrial pools this review also accepts - so its breadth is imprecision rather than error; it is already a core-function location here and the IEA, ISO and IDA cytoplasm rows are accepted.
Propagation Review
Root cause: NO FAILURE CORE
Sources checked:
PANTHER:PTN000019791 · ancestral node of PANTHER family PTHR10177 (CYCLINS) SUPPORTS TRANSFER
The cytoplasm IBD sits at this deep cyclin node, whose seeds for the term include Arabidopsis, budding-yeast, fission-yeast, fly, rat and mouse cyclins. A cytoplasmic pool is therefore an ancestral property of the family, and descent from the node carries it soundly to mouse Ccnb1.
MGI:MGI:88302 · mouse Ccnb1 (this gene) SUPPORTS TRANSFER
The target's own IBD seed. Mouse Ccnb1's experimental cytoplasm annotation (IDA in GOA) is one of the descendant evidences behind this node, so its appearance here marks experimental grounding on the target itself.
MGI:MGI:88313 · mouse Ccnd1 (cyclin D1) SUPPORTS TRANSFER
A mammalian D-type cyclin seed at the same node; the cytoplasmic pool is not confined to the mitotic B-type branch. Symbol corroborated via the family index (PTHR10177-entries.csv, UniProtKB:P25322, gene Ccnd1), not from this MGI id.
SGD:S000004812 SUPPORTS TRANSFER
Budding-yeast seed cited by identifier because the local index does not resolve it; part of the fungal coverage of this node for the cytoplasm term.
Supporting Evidence:
file:mouse/Ccnb1/Ccnb1-deep-research-falcon.md
Cyclin B1 is spatially regulated: it shuttles between cytoplasm and nucleus and becomes nuclear at mitotic entry
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.
Propagation Review
Root cause: TERM SCOPING PROBLEM
Failure modes: GRANULARITY MISMATCH
Sources checked:
PANTHER:PTN000019791 · ancestral node of PANTHER family PTHR10177 (CYCLINS) SUPPORTS TRANSFER
The CDK-partner role is exactly what this deep cyclin node encodes, and it transfers correctly to cyclin B1; the seeds run from Candida, budding-yeast and fission-yeast cyclins through fly cyclins to the mammalian ones. The fault is only that a node-level term covering every cyclin class stops at the generic regulator parent, whereas cyclin B1's specific role is to activate CDK1.
MGI:MGI:88313 · mouse Ccnd1 (cyclin D1) SUPPORTS TRANSFER
A mammalian cyclin seed that is likewise a non-catalytic activating subunit of its CDK, so the regulator biology transfers and only the term's generality is at issue. Symbol corroborated via the family index (PTHR10177-entries.csv, UniProtKB:P25322, gene Ccnd1), not from this MGI id.
MGI:MGI:88316 · mouse Ccne1 (cyclin E1) SUPPORTS TRANSFER
A second mammalian cyclin seed carrying its own experimental evidence for this term. Symbol resolved from the MOD id itself, the most direct of the routes used in this file - Ccne1-uniprot.txt carries the cross-reference "DR MGI; MGI:88316; Ccne1.".
PomBase:SPBC19F5.01c SUPPORTS TRANSFER
Fission-yeast seed cited by identifier because the local index does not resolve it; it is part of the fungal coverage showing the CDK-regulator role predates animals.
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...
UNDECIDED
Summary: Cannot be adjudicated here: PMID:19376971 is cached abstract-only. Prior observation, not a verdict: The cited Filia paper does not support Ccnb1 nuclear localization.
Reason: PMID:19376971 is cached abstract-only, so the curator's experimental evidence cannot be inspected here; per CLAUDE.md an experimental annotation is not overruled on that basis. Recorded observation, not a verdict: PMID:19376971 describes Filia effects on spindle assembly and checkpoint regulators in embryos, not cyclin B1 localization. Cyclin B1 nuclear localization is supported elsewhere, and that assertion is what could not be checked.
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...
UNDECIDED
Summary: Cannot be adjudicated here: PMID:14993286 is cached abstract-only. Prior observation, not a verdict: The cited cyclin F paper does not support Ccnb1 nuclear localization.
Reason: PMID:14993286 is cached abstract-only, so the curator's experimental evidence cannot be inspected here; per CLAUDE.md an experimental annotation is not overruled on that basis. Recorded observation, not a verdict: PMID:14993286 describes cyclin F disruption and related cell-cycle defects, not Ccnb1/cyclin B1 localization. Cyclin B1 nuclear localization is supported elsewhere, and that assertion is what could not be checked.
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

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Deep Research

Falcon

(Ccnb1-deep-research-falcon.md)

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