ABRAXAS1 encodes a nuclear BRCA1-A complex subunit that acts as a scaffold linking BRCA1, UIMC1/RAP80, BRCC3/BRCC36, BABAM proteins, and ubiquitin-dependent DNA damage-site signaling. The protein contains an MPN-like domain, binds polyubiquitin as part of the BRCA1-A/RAP80 complex, and supports BRCA1 recruitment, DNA double-strand break repair, K63-ubiquitin signal editing by BRCC36, and G2/M DNA damage checkpoint responses.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
|
GO:0005634
nucleus
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage sites within the nucleus.
Reason: The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes BRCA1-A complex activity at DNA double-strand breaks.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121, ECO:0000269|PubMed:17643122}.
PMID:17525340
RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response to ionizing radiation
|
|
GO:0008017
microtubule binding
|
IBA
GO_REF:0000033 |
REMOVE |
Summary: Likely paralog/family over-propagation. The IBA trace for this microtubule-binding term cites ABRAXAS2 rather than ABRAXAS1-specific evidence.
Reason: ABRAXAS1 literature, UniProt, Reactome, and PN context support a nuclear BRCA1-A DNA damage-response scaffold, not microtubule binding. No ABRAXAS1-specific microtubule-binding evidence was found in the cached evidence set.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Involved in DNA damage response and double-strand break (DSB) repair.
file:human/ABRAXAS1/ABRAXAS1-notes.md
The IBA microtubule/spindle annotations are projected through a PANTHER node supported by ABRAXAS2
|
|
GO:0008608
attachment of spindle microtubules to kinetochore
|
IBA
GO_REF:0000033 |
REMOVE |
Summary: Likely paralog/family over-propagation. The kinetochore-microtubule attachment IBA is not supported by ABRAXAS1-specific DNA damage literature.
Reason: The with/from metadata points to ABRAXAS2 for the spindle branch, while ABRAXAS1 evidence supports BRCA1-A complex-mediated DNA damage signaling. This process would overstate ABRAXAS1 biology.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Involved in DNA damage response and double-strand break (DSB) repair.
file:human/ABRAXAS1/ABRAXAS1-notes.md
I marked `microtubule binding`, `attachment of spindle microtubules to kinetochore`, and `mitotic spindle assembly` for removal for ABRAXAS1.
|
|
GO:0031593
polyubiquitin modification-dependent protein binding
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: Core molecular function. ABRAXAS1 is part of a BRCA1-A/RAP80 complex that recognizes ubiquitinated damage-site chromatin and has polyubiquitin-binding capacity.
Reason: The term captures the ubiquitin-recognition side of ABRAXAS1 biology better than generic protein binding. It should be retained for both direct IDA and IBA evidence.
Supporting Evidence:
PMID:19261749
four members of the BRCA1-A complex possess a polyubiquitin chain-binding capability
PMID:20656689
RAP80, in turn, is recruited to DSBs through its tandem ubiquitin-interacting motifs (UIMs) ( 6 , 14 – 16 ), which specifically recognize K63-Ub chains
|
|
GO:0090307
mitotic spindle assembly
|
IBA
GO_REF:0000033 |
REMOVE |
Summary: Likely paralog/family over-propagation. The mitotic-spindle-assembly IBA is not supported for ABRAXAS1 by the reviewed evidence.
Reason: ABRAXAS1 participates in nuclear DNA damage repair/checkpoint signaling. The PANTHER IBA spindle call is traceable to ABRAXAS2 and should not be propagated to ABRAXAS1 without gene-specific evidence.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Involved in DNA damage response and double-strand break (DSB) repair.
file:human/ABRAXAS1/ABRAXAS1-notes.md
I marked `microtubule binding`, `attachment of spindle microtubules to kinetochore`, and `mitotic spindle assembly` for removal for ABRAXAS1.
|
|
GO:0005634
nucleus
|
IEA
GO_REF:0000044 |
ACCEPT |
Summary: Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage sites within the nucleus.
Reason: The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes BRCA1-A complex activity at DNA double-strand breaks.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121, ECO:0000269|PubMed:17643122}.
PMID:17525340
RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response to ionizing radiation
|
|
GO:0005515
protein binding
|
IPI
PMID:17525340 Abraxas and RAP80 form a BRCA1 protein complex required for ... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:17525340
identified a protein, Abraxas, that directly binds the BRCA1 BRCT repeats
PMID:20656689
The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36, BRCC45, Abraxas, and MERIT40
|
|
GO:0005515
protein binding
|
IPI
PMID:17643121 CCDC98 targets BRCA1 to DNA damage sites. |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:17643121
CCDC98 is a BRCA1 binding partner that mediates BRCA1 function in response to DNA damage.
PMID:20656689
The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36, BRCC45, Abraxas, and MERIT40
|
|
GO:0005515
protein binding
|
IPI
PMID:18077395 Ubc13/Rnf8 ubiquitin ligases control foci formation of the R... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:18077395
Rap80 contains an Abraxas interaction domain
PMID:20656689
The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36, BRCC45, Abraxas, and MERIT40
|
|
GO:0005515
protein binding
|
IPI
PMID:19615732 Defining the human deubiquitinating enzyme interaction lands... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:19615732
We identified 774 candidate interacting proteins associated with 75 Dubs.
|
|
GO:0005515
protein binding
|
IPI
PMID:29656893 DNA Repair Network Analysis Reveals Shieldin as a Key Regula... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:29656893
we generated high-resolution interaction neighborhood maps of the endogenously expressed DNA repair factors 53BP1, BRCA1, and MDC1
|
|
GO:0005515
protein binding
|
IPI
PMID:34591612 A protein interaction landscape of breast cancer. |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:34591612
we generated comprehensive interaction maps for 40 frequently altered BC proteins
|
|
GO:0005515
protein binding
|
IPI
PMID:35156780 CFTR interactome mapping using the mammalian membrane two-hy... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:35156780
high-throughput screening variant of the Mammalian Membrane Two-Hybrid
|
|
GO:0005515
protein binding
|
IPI
PMID:36012204 Differential CFTR-Interactome Proximity Labeling Procedures ... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:36012204
proximity labeling approaches identified both known and additional CFTR protein partners
|
|
GO:0005515
protein binding
|
IPI
PMID:39009827 Proteome-scale characterisation of motif-based interactome r... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:39009827
we identified 366 mutation-modulated interactions
|
|
GO:0016604
nuclear body
|
IDA
GO_REF:0000052 |
KEEP AS NON CORE |
Summary: Non-core localization. HPA reports nuclear-body staining, while mechanistic ABRAXAS1 biology centers on DNA damage foci/BRCA1-A complex recruitment.
Reason: This cellular component is plausible as a localization observation, but it is less informative than nucleus/nucleoplasm and BRCA1-A complex membership for the gene product function.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Localizes at sites of DNA damage at double-strand breaks (DSBs).
|
|
GO:0005634
nucleus
|
NAS
PMID:20656689 Differential regulation of JAMM domain deubiquitinating enzy... |
ACCEPT |
Summary: Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage sites within the nucleus.
Reason: The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes BRCA1-A complex activity at DNA double-strand breaks.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121, ECO:0000269|PubMed:17643122}.
PMID:17525340
RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response to ionizing radiation
|
|
GO:0006282
regulation of DNA repair
|
NAS
PMID:20656689 Differential regulation of JAMM domain deubiquitinating enzy... |
MODIFY |
Summary: The broad regulation-of-DNA-repair annotation is directionally correct but less precise than positive regulation of DNA repair for ABRAXAS1.
Reason: ABRAXAS1 promotes BRCA1-A complex recruitment/stability and DNA repair after damage; the reviewed IMP annotations already use the more informative positive-regulation term.
Proposed replacements:
positive regulation of DNA repair
Supporting Evidence:
PMID:17525340
Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and DNA repair.
PMID:19261748
a stable complex containing MERIT40 acts early in DNA damage response and regulates damage-dependent BRCA1 localization
|
|
GO:0044818
mitotic G2/M transition checkpoint
|
NAS
PMID:22369660 BRCA1 tumor suppressor network: focusing on its tail. |
MODIFY |
Summary: The ComplexPortal/NAS checkpoint annotation is real but should be represented using the more specific DNA-damage checkpoint signaling term.
Reason: ABRAXAS1 evidence concerns BRCA1-dependent G2/M checkpoint activation in response to DNA damage, not the generic mitotic G2/M transition checkpoint.
Proposed replacements:
mitotic G2 DNA damage checkpoint signaling
Supporting Evidence:
PMID:17643121
CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent G2/M checkpoint activation
PMID:22369660
Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out functions of BRCA1 in cell cycle checkpoint control.
|
|
GO:0070531
BRCA1-A complex
|
NAS
PMID:20656689 Differential regulation of JAMM domain deubiquitinating enzy... |
ACCEPT |
Summary: Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36, BABAM proteins, and related DDR functions.
Reason: Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more precise than the PN-projected generic ubiquitin-ligase-complex bucket.
Supporting Evidence:
PMID:19261749
Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0007095
mitotic G2 DNA damage checkpoint signaling
|
IMP
PMID:17525340 Abraxas and RAP80 form a BRCA1 protein complex required for ... |
ACCEPT |
Summary: Core checkpoint process. ABRAXAS1/CCDC98 is required for BRCA1-dependent G2/M checkpoint signaling after DNA damage.
Reason: The original ABRAXAS1/CCDC98 work and later BRCA1-A review evidence support a G2 DNA damage checkpoint role. This is part of the DNA damage response function rather than a general mitotic-spindle role.
Supporting Evidence:
PMID:17643121
CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent G2/M checkpoint activation
PMID:22369660
Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out functions of BRCA1 in cell cycle checkpoint control.
|
|
GO:0007095
mitotic G2 DNA damage checkpoint signaling
|
IMP
PMID:17643121 CCDC98 targets BRCA1 to DNA damage sites. |
ACCEPT |
Summary: Core checkpoint process. ABRAXAS1/CCDC98 is required for BRCA1-dependent G2/M checkpoint signaling after DNA damage.
Reason: The original ABRAXAS1/CCDC98 work and later BRCA1-A review evidence support a G2 DNA damage checkpoint role. This is part of the DNA damage response function rather than a general mitotic-spindle role.
Supporting Evidence:
PMID:17643121
CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent G2/M checkpoint activation
PMID:22369660
Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out functions of BRCA1 in cell cycle checkpoint control.
|
|
GO:0007095
mitotic G2 DNA damage checkpoint signaling
|
IMP
PMID:19261748 MERIT40 facilitates BRCA1 localization and DNA damage repair... |
ACCEPT |
Summary: Core checkpoint process. ABRAXAS1/CCDC98 is required for BRCA1-dependent G2/M checkpoint signaling after DNA damage.
Reason: The original ABRAXAS1/CCDC98 work and later BRCA1-A review evidence support a G2 DNA damage checkpoint role. This is part of the DNA damage response function rather than a general mitotic-spindle role.
Supporting Evidence:
PMID:17643121
CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent G2/M checkpoint activation
PMID:22369660
Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out functions of BRCA1 in cell cycle checkpoint control.
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5683384 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5683385 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5683735 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5683801 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5684052 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5684071 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5686685 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5691411 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-5693551 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005654
nucleoplasm
|
TAS
Reactome:R-HSA-69891 |
ACCEPT |
Summary: Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1 are modeled at nuclear DNA double-strand breaks.
Reason: The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
Supporting Evidence:
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0005515
protein binding
|
IPI
PMID:19261748 MERIT40 facilitates BRCA1 localization and DNA damage repair... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:19261748
CCDC98 binds to RAP80 via a large N-terminal region
PMID:20656689
The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36, BRCC45, Abraxas, and MERIT40
|
|
GO:0005515
protein binding
|
IPI
PMID:19261749 NBA1, a new player in the Brca1 A complex, is required for D... |
MARK AS OVER ANNOTATED |
Summary: Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
Reason: These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome rows are even less suitable as function claims.
Supporting Evidence:
PMID:19261749
four members of the BRCA1-A complex possess a polyubiquitin chain-binding capability
PMID:20656689
The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36, BRCC45, Abraxas, and MERIT40
|
|
GO:0005634
nucleus
|
IDA
PMID:17525340 Abraxas and RAP80 form a BRCA1 protein complex required for ... |
ACCEPT |
Summary: Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage sites within the nucleus.
Reason: The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes BRCA1-A complex activity at DNA double-strand breaks.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121, ECO:0000269|PubMed:17643122}.
PMID:17525340
RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response to ionizing radiation
|
|
GO:0005634
nucleus
|
IDA
PMID:17643121 CCDC98 targets BRCA1 to DNA damage sites. |
ACCEPT |
Summary: Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage sites within the nucleus.
Reason: The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes BRCA1-A complex activity at DNA double-strand breaks.
Supporting Evidence:
file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121, ECO:0000269|PubMed:17643122}.
PMID:17525340
RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response to ionizing radiation
|
|
GO:0006302
double-strand break repair
|
IMP
PMID:17525340 Abraxas and RAP80 form a BRCA1 protein complex required for ... |
ACCEPT |
Summary: Core biological process. ABRAXAS1 is required for efficient DNA double-strand break repair through BRCA1-A recruitment and ubiquitin-dependent damage-site signaling.
Reason: Loss/depletion experiments in the original ABRAXAS1/CCDC98 papers support DNA repair and DNA damage resistance. The PN-projected broader DNA repair term is already entailed by this annotation.
Supporting Evidence:
PMID:17525340
Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and DNA repair.
PMID:19261748
a stable complex containing MERIT40 acts early in DNA damage response and regulates damage-dependent BRCA1 localization
|
|
GO:0006302
double-strand break repair
|
IMP
PMID:17643121 CCDC98 targets BRCA1 to DNA damage sites. |
ACCEPT |
Summary: Core biological process. ABRAXAS1 is required for efficient DNA double-strand break repair through BRCA1-A recruitment and ubiquitin-dependent damage-site signaling.
Reason: Loss/depletion experiments in the original ABRAXAS1/CCDC98 papers support DNA repair and DNA damage resistance. The PN-projected broader DNA repair term is already entailed by this annotation.
Supporting Evidence:
PMID:17525340
Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and DNA repair.
PMID:19261748
a stable complex containing MERIT40 acts early in DNA damage response and regulates damage-dependent BRCA1 localization
|
|
GO:0006302
double-strand break repair
|
IMP
PMID:19261748 MERIT40 facilitates BRCA1 localization and DNA damage repair... |
ACCEPT |
Summary: Core biological process. ABRAXAS1 is required for efficient DNA double-strand break repair through BRCA1-A recruitment and ubiquitin-dependent damage-site signaling.
Reason: Loss/depletion experiments in the original ABRAXAS1/CCDC98 papers support DNA repair and DNA damage resistance. The PN-projected broader DNA repair term is already entailed by this annotation.
Supporting Evidence:
PMID:17525340
Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and DNA repair.
PMID:19261748
a stable complex containing MERIT40 acts early in DNA damage response and regulates damage-dependent BRCA1 localization
|
|
GO:0010212
response to ionizing radiation
|
IMP
PMID:17525340 Abraxas and RAP80 form a BRCA1 protein complex required for ... |
KEEP AS NON CORE |
Summary: Supported but non-core phenotype/context annotation. Ionizing radiation is the experimental damage stimulus used to reveal ABRAXAS1 DNA damage-response function.
Reason: The IR response annotations should be retained as useful experimental context, but the core process is DNA double-strand break repair/checkpoint signaling through BRCA1-A.
Supporting Evidence:
PMID:18077395
the entire Brca1 A complex to DNA-damage foci
PMID:19261749
required for resistance to ionizing radiation
|
|
GO:0010212
response to ionizing radiation
|
IMP
PMID:17643121 CCDC98 targets BRCA1 to DNA damage sites. |
KEEP AS NON CORE |
Summary: Supported but non-core phenotype/context annotation. Ionizing radiation is the experimental damage stimulus used to reveal ABRAXAS1 DNA damage-response function.
Reason: The IR response annotations should be retained as useful experimental context, but the core process is DNA double-strand break repair/checkpoint signaling through BRCA1-A.
Supporting Evidence:
PMID:18077395
the entire Brca1 A complex to DNA-damage foci
PMID:19261749
required for resistance to ionizing radiation
|
|
GO:0010212
response to ionizing radiation
|
IMP
PMID:19261748 MERIT40 facilitates BRCA1 localization and DNA damage repair... |
KEEP AS NON CORE |
Summary: Supported but non-core phenotype/context annotation. Ionizing radiation is the experimental damage stimulus used to reveal ABRAXAS1 DNA damage-response function.
Reason: The IR response annotations should be retained as useful experimental context, but the core process is DNA double-strand break repair/checkpoint signaling through BRCA1-A.
Supporting Evidence:
PMID:18077395
the entire Brca1 A complex to DNA-damage foci
PMID:19261749
required for resistance to ionizing radiation
|
|
GO:0031593
polyubiquitin modification-dependent protein binding
|
IDA
PMID:19261749 NBA1, a new player in the Brca1 A complex, is required for D... |
ACCEPT |
Summary: Core molecular function. ABRAXAS1 is part of a BRCA1-A/RAP80 complex that recognizes ubiquitinated damage-site chromatin and has polyubiquitin-binding capacity.
Reason: The term captures the ubiquitin-recognition side of ABRAXAS1 biology better than generic protein binding. It should be retained for both direct IDA and IBA evidence.
Supporting Evidence:
PMID:19261749
four members of the BRCA1-A complex possess a polyubiquitin chain-binding capability
PMID:20656689
RAP80, in turn, is recruited to DSBs through its tandem ubiquitin-interacting motifs (UIMs) ( 6 , 14 – 16 ), which specifically recognize K63-Ub chains
|
|
GO:0045739
positive regulation of DNA repair
|
IMP
PMID:17525340 Abraxas and RAP80 form a BRCA1 protein complex required for ... |
ACCEPT |
Summary: Core regulatory process. ABRAXAS1 positively supports DNA repair by assembling/stabilizing the RAP80-BRCA1-A complex at DNA damage sites.
Reason: The evidence supports a positive role in DNA repair through BRCA1 localization, complex integrity, and BRCC36-associated ubiquitin editing rather than direct DNA repair catalysis.
Supporting Evidence:
PMID:17525340
Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and DNA repair.
PMID:19261748
a stable complex containing MERIT40 acts early in DNA damage response and regulates damage-dependent BRCA1 localization
PMID:20656689
Abraxas and BRCC45 were essential for BRCC36 DUB activity within the RAP80 complex
|
|
GO:0045739
positive regulation of DNA repair
|
IMP
PMID:19261748 MERIT40 facilitates BRCA1 localization and DNA damage repair... |
ACCEPT |
Summary: Core regulatory process. ABRAXAS1 positively supports DNA repair by assembling/stabilizing the RAP80-BRCA1-A complex at DNA damage sites.
Reason: The evidence supports a positive role in DNA repair through BRCA1 localization, complex integrity, and BRCC36-associated ubiquitin editing rather than direct DNA repair catalysis.
Supporting Evidence:
PMID:17525340
Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and DNA repair.
PMID:19261748
a stable complex containing MERIT40 acts early in DNA damage response and regulates damage-dependent BRCA1 localization
PMID:20656689
Abraxas and BRCC45 were essential for BRCC36 DUB activity within the RAP80 complex
|
|
GO:0070531
BRCA1-A complex
|
IDA
PMID:17525340 Abraxas and RAP80 form a BRCA1 protein complex required for ... |
ACCEPT |
Summary: Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36, BABAM proteins, and related DDR functions.
Reason: Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more precise than the PN-projected generic ubiquitin-ligase-complex bucket.
Supporting Evidence:
PMID:19261749
Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0070531
BRCA1-A complex
|
IDA
PMID:19261746 MERIT40 controls BRCA1-Rap80 complex integrity and recruitme... |
ACCEPT |
Summary: Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36, BABAM proteins, and related DDR functions.
Reason: Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more precise than the PN-projected generic ubiquitin-ligase-complex bucket.
Supporting Evidence:
PMID:19261749
Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0070531
BRCA1-A complex
|
IDA
PMID:19261748 MERIT40 facilitates BRCA1 localization and DNA damage repair... |
ACCEPT |
Summary: Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36, BABAM proteins, and related DDR functions.
Reason: Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more precise than the PN-projected generic ubiquitin-ligase-complex bucket.
Supporting Evidence:
PMID:19261749
Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
|
GO:0070531
BRCA1-A complex
|
IDA
PMID:19261749 NBA1, a new player in the Brca1 A complex, is required for D... |
ACCEPT |
Summary: Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36, BABAM proteins, and related DDR functions.
Reason: Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more precise than the PN-projected generic ubiquitin-ligase-complex bucket.
Supporting Evidence:
PMID:19261749
Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
Reactome:R-HSA-5683385
Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A complex at DNA DSBs
|
Q: Should GO curation represent ABRAXAS1 only as part of the BRCA1-A complex, or is there enough evidence to annotate ABRAXAS1 to a broader ubiquitin ligase complex term despite its scaffold/DUB-support role?
Suggested experts: Wang B, Greenberg RA, Elledge SJ
Q: Given evidence that ABRAXAS1 truncations shift BRCA1 partitioning toward BRCA1-C and derepress mutagenic repair (SSA/MMEJ) without impairing HR, should ABRAXAS1 carry a negative-regulation annotation for low-fidelity double-strand break repair pathways (e.g. single-strand annealing) in addition to its positive role in DNA repair?
Suggested experts: Wiesmuller L, Pylkas K
Q: Is the reported RNA-dependent / direct RNA-binding behavior of ABRAXAS1 (R-DeeP and iCLIP2 in a single lung-cancer cell line) reproducible and functionally meaningful, or a cell-line-specific high-throughput artifact, before any RNA-binding annotation is considered?
Suggested experts: Diederichs S
Experiment: Compare ABRAXAS1 and ABRAXAS2 depletion or rescue in synchronized human cells using spindle assembly, kinetochore-microtubule attachment, and DNA damage-response readouts in the same experimental system.
Hypothesis: The PANTHER-derived spindle and microtubule annotations are ABRAXAS2/paralog-specific and do not apply to ABRAXAS1.
Type: comparative cell biology
Experiment: Use chromosomally integrated DSB-repair reporters (HR, NHEJ, MMEJ, SSA) in cells expressing wild-type ABRAXAS1 versus C-terminal SPTF-motif and BRCC36-interaction truncation variants, measuring pathway-frequency shifts and end-resection markers (RPA, pRPA32, MRE11) to test pathway-choice control.
Hypothesis: ABRAXAS1 restrains end resection and mutagenic double-strand break repair (single-strand annealing / microhomology-mediated end joining) by sequestering BRCA1 in the BRCA1-A complex, rather than simply promoting homologous recombination.
Type: DSB-repair pathway reporter assay
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.
ABRAXAS1 (UniProt Q6UWZ7) is the human protein also known as ABRA1/CCDC98/FAM175A and is the BRCA1-A complex subunit Abraxas 1. Multiple independent sources explicitly match these synonyms and the expected size (~409 aa) and functional motifs/domains (MPN-like N-terminus, NLS around residues 358–361, and C-terminal phospho-SPxF/“SPTF” BRCT-binding motif), confirming the correct target and distinguishing it from its paralog ABRO1/Abraxas2 (which specifies BRISC rather than BRCA1-A). (julius2020brca1aandbrisc pages 1-3, bose2019brca1mislocalizationleads pages 1-3, julius2020brca1aandbrisc pages 3-6)
| Feature | Molecular detail (residues/motif where available) | Functional consequence | Key sources (citation IDs) | URL (if available) |
|---|---|---|---|---|
| Verified identity | Human ABRAXAS1 / ABRA1 / CCDC98 / FAM175A; UniProt Q6UWZ7; ~409 aa scaffold/adaptor | Confirms the target is the BRCA1-A complex subunit Abraxas 1, not the paralog ABRO1/Abraxas2 | (julius2020brca1aandbrisc pages 1-3, bose2019brca1mislocalizationleads pages 1-3) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1093/hmg/ddz252 |
| N-terminal MPN-like domain | JAMM/MPN− domain; aa ~11–121; catalytically inactive due to loss of Zn-binding catalytic configuration | Binds and activates the catalytic MPN+ DUB BRCC36; scaffold role rather than protease activity | (julius2020brca1aandbrisc pages 3-6, kyrieleis2016threedimensionalarchitectureof pages 3-4) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1016/j.celrep.2016.11.063 |
| Coiled-coil region | aa ~206–260 | Supports higher-order assembly/dimerization and contributes to interactions within BRCA1-A; loss with deeper truncation derepresses mutagenic DSBR pathways | (julius2020brca1aandbrisc pages 3-6, sachsenweger2023abraxas1orchestratesbrca1 pages 1-2, sachsenweger2023abraxas1orchestratesbrca1 pages 8-9) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1038/s41419-023-05845-6 |
| Nuclear localization signal (NLS) | aa ~358–361; includes Arg361 | Required for nuclear import of ABRAXAS1/BRCA1-A; R361Q impairs nuclear localization and BRCA1 focus formation | (julius2020brca1aandbrisc pages 3-6, bose2019brca1mislocalizationleads pages 1-3, kliche2024proteomescalecharacterisationof pages 11-13) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1093/hmg/ddz252; https://doi.org/10.1038/s44320-024-00055-4 |
| C-terminal BRCA1-binding motif | pSPxF / SPTF motif at aa ~406–409; S404 damage-inducible, S406 constitutive, terminal F409 critical | Phospho-dependent binding to BRCA1 BRCT domains; drives BRCA1 recruitment/sequestration in BRCA1-A | (julius2020brca1aandbrisc pages 11-13, bose2019brca1mislocalizationleads pages 1-3, sachsenweger2023abraxas1orchestratesbrca1 pages 12-13) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1093/hmg/ddz252; https://doi.org/10.1038/s41419-023-05845-6 |
| BRCC36 interaction | N-terminal scaffold interaction via MPN dimer with BRCC36 | Activates the K63-specific BRCC36 deubiquitinase and organizes the DUB core | (julius2020brca1aandbrisc pages 3-6, julius2020brca1aandbrisc pages 8-11, kyrieleis2016threedimensionalarchitectureof pages 1-3) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1016/j.celrep.2016.11.063 |
| RAP80 integration | ABRAXAS1 C-terminal/unstructured region binds on top of RAP80; RAP80 is constitutive BRCA1-A subunit | Couples BRCA1-A to K63-Ub and SUMO-ubiquitin damage marks at DSB-flanking chromatin | (julius2020brca1aandbrisc pages 3-6, julius2019structuralbasisof pages 10-12) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1016/j.molcel.2019.06.002 |
| BRCA1-A complex membership | Core complex: ABRAXAS1, BRCC36, BRE/BRCC45, MERIT40, RAP80; BRCA1 binds via ABRAXAS1 phospho-tail | Recruits/positions BRCA1-A at DNA damage foci, edits K63-Ub chromatin signals, limits end resection and suppresses excessive HR/SSA | (julius2020brca1aandbrisc pages 1-3, julius2019structuralbasisof pages 10-12, sachsenweger2023abraxas1orchestratesbrca1 pages 1-2) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1016/j.molcel.2019.06.002; https://doi.org/10.1038/s41419-023-05845-6 |
| BRISC distinction | ABRAXAS1 is not the BRISC-specific adaptor; ABRO1/Abraxas2 replaces ABRAXAS1 in BRISC | Explains why ABRAXAS1 is primarily linked to nuclear DNA-damage signaling, whereas BRISC has mostly non-nuclear/immune roles | (julius2020brca1aandbrisc pages 1-3, julius2019structuralbasisof pages 1-3) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1016/j.molcel.2019.06.002 |
| Cellular localization | Predominantly nuclear; nuclear import depends on ABRAXAS1 NLS; BRCA1-A accumulates at DNA repair foci | Ensures BRCA1-A function at chromatin near DSBs; defective localization perturbs DDR and checkpoint control | (julius2020brca1aandbrisc pages 3-6, julius2019structuralbasisof pages 1-3, bose2019brca1mislocalizationleads pages 1-3) | https://doi.org/10.3390/biom10111503; https://doi.org/10.1016/j.molcel.2019.06.002; https://doi.org/10.1093/hmg/ddz252 |
| Structural architecture | BRCA1-A core forms a V-shaped superdimer/dimer-of-heterotetramers with ABRAXAS1-BRCC36 at the base and BRCC45/MERIT40 in the arms | Supports stable assembly, substrate engagement, and efficient K63-linked ubiquitin-chain processing | (kyrieleis2016threedimensionalarchitectureof pages 5-6, kyrieleis2016threedimensionalarchitectureof pages 1-3) | https://doi.org/10.1016/j.celrep.2016.11.063 |
| DUB pathway function | BRCC36 active site is K63-linkage specific; ABRAXAS1 acts as DEUBAD-like adaptor and targeting subunit | Places K63-specific deubiquitination on chromatin at DNA breaks; helps delimit ubiquitin signaling domains around lesions | (julius2020brca1aandbrisc pages 3-6, julius2020brca1aandbrisc pages 8-11, julius2020brca1aandbrisc pages 1-3) | https://doi.org/10.3390/biom10111503 |
| Patient-relevant truncation variants | c.1106dup (p.Ser370Ilefs2) loses C-terminal BRCA1-binding motif; c.577C>T (p.Arg193) also lacks BRCC36-interaction region | Shift BRCA1 partitioning from BRCA1-A toward BRCA1-C, increase SSA/MMEJ/NHEJ-associated phenotypes, and destabilize genome maintenance | (sachsenweger2023abraxas1orchestratesbrca1 pages 3-6, sachsenweger2023abraxas1orchestratesbrca1 pages 8-9, sachsenweger2023abraxas1orchestratesbrca1 media db056916) | https://doi.org/10.1038/s41419-023-05845-6 |
| RNA-dependent / RNA-binding evidence | Identified as RNA-dependent protein in A549 cells; direct RNA interaction validated by iCLIP2 | Suggests an additional context-dependent RNA-associated behavior beyond canonical BRCA1-A scaffolding | (rajagopal2022proteomewideidentificationof pages 1-2, rajagopal2022proteomewideidentificationof pages 5-7) | https://doi.org/10.3390/cancers14246109 |
Table: This table compacts the key domain architecture, binding partners, complex membership, and localization features of human ABRAXAS1 (Q6UWZ7). It is useful as a quick-reference map linking specific motifs and residues to experimentally supported functions and recent disease-relevant findings.
ABRAXAS1 is best understood as a non-catalytic scaffold/adaptor subunit that organizes and targets the BRCA1-A deubiquitinase (DUB) complex to DNA damage–marked chromatin. In BRCA1-A, ABRAXAS1 assembles with BRCC36 (also called BRCC3), BRE/BRCC45, MERIT40, and RAP80, and then binds BRCA1 via a phospho-dependent interaction between the ABRAXAS1 C-terminus and the BRCA1 BRCT domains. (julius2020brca1aandbrisc pages 1-3, julius2019structuralbasisof pages 10-12, sachsenweger2023abraxas1orchestratesbrca1 pages 1-2)
ABRAXAS1 contains an N-terminal JAMM/MPN-like domain that is catalytically inactive (“MPN−”) and functions as an activator/scaffold for the catalytically active JAMM/MPN+ metalloprotease BRCC36. This is a central definitional point: ABRAXAS1 itself does not catalyze deubiquitination; instead it allosterically activates and positions BRCC36 within a multi-protein machine. (julius2020brca1aandbrisc pages 3-6, kyrieleis2016threedimensionalarchitectureof pages 3-4)
A key organizing concept in the field is that BRCC36 forms the enzymatic core of two distinct assemblies: (i) BRCA1-A (nuclear, DNA damage–associated) and (ii) BRISC (largely non-nuclear, immune/other signaling contexts). ABRAXAS1 and its paralog ABRO1 partition the shared BRCC36/BRE/MERIT40 core into BRCA1-A versus BRISC, respectively, thus providing targeting and regulatory specialization without changing the catalytic subunit. (julius2020brca1aandbrisc pages 1-3, julius2019structuralbasisof pages 1-3)
At DNA double-strand breaks (DSBs), upstream signaling generates K63-linked ubiquitin chains on chromatin (e.g., via RNF8/RNF168 pathway), which are recognized by RAP80 and thereby recruit BRCA1-A to DNA damage foci. ABRAXAS1 is central in this architecture because it integrates RAP80 into BRCA1-A and provides the phosphorylated BRCA1-binding tail. (bose2019brca1mislocalizationleads pages 1-3, julius2019structuralbasisof pages 10-12)
Mechanistically, ABRAXAS1 has:
- A nuclear localization signal (NLS; ~aa 358–361) required for nuclear localization of the BRCA1-A–BRCA1 assembly. (julius2020brca1aandbrisc pages 3-6, bose2019brca1mislocalizationleads pages 1-3)
- A C-terminal phospho-motif (commonly described as pSPxF/SPTF; ~aa 406–409) with phosphorylation sites including S404 (damage-inducible) and S406 (constitutive) that is recognized by BRCA1 BRCT domains, enabling phospho-dependent recruitment/sequestration. (julius2020brca1aandbrisc pages 11-13, bose2019brca1mislocalizationleads pages 1-3)
Structural and mechanistic work emphasizes that BRCA1-A can sequester BRCA1 in a high-affinity complex via ABRAXAS1’s BRCT-binding phospho-tail, and that BRCA1-A localization to DSB-flanking regions can limit end resection and thereby suppress homologous recombination (HR) under some contexts—conceptually positioning BRCA1-A as a “fine-tuner” of BRCA1 activities and repair pathway choice rather than a simple HR-promoting factor. (julius2020brca1aandbrisc pages 1-3, julius2019structuralbasisof pages 10-12)
Negative-stain EM of a reconstituted human BRCA1-A core complex (Abraxas/BRCC36/BRCC45/MERIT40) supports a V-shaped “superdimer” (dimer of heterotetramers) architecture, with ABRAXAS1/BRCC36 at the base and BRCC45/MERIT40 in the arms. This architecture explains how a scaffold like ABRAXAS1 contributes to stable assembly and productive substrate engagement. (kyrieleis2016threedimensionalarchitectureof pages 1-3, kyrieleis2016threedimensionalarchitectureof pages 5-6)
BRCC36 is a Zn2+-dependent JAMM/MPN metalloprotease and exhibits strict K63-linkage specificity, while ABRAXAS1 (MPN−) acts as a DEUBAD-like adaptor to activate BRCC36 upon assembly. A mechanistic model described in the BRCA1-A/BRISC review proposes that BRCC36 is inactive in isolation (E-loop disorder) and is activated by dimerization with ABRAXAS1 (or ABRO1 in BRISC), which helps position catalytic elements and enables substrate processing. (julius2020brca1aandbrisc pages 8-11, julius2020brca1aandbrisc pages 3-6)
The same review describes additional selectivity features: assembled complexes can show preference for longer K63 chains (≥4 ubiquitins), potentially via accessory ubiquitin-recognition subunits (e.g., BRE and MERIT40), and RAP80 can enhance targeting to mixed SUMO–K63 chains at DNA breaks—helping rationalize context-dependent substrate selection. (julius2020brca1aandbrisc pages 8-11)
Structural work further emphasizes that BRCA1 BRCT binding to an ABRAXAS1 phospho-peptide is mutually incompatible with BRCT interactions with other partners (e.g., CtIP, BACH1), and that the assembled BRCA1-A architecture produces high avidity (nanomolar-range) BRCA1 association. This provides a mechanistic basis for how ABRAXAS1-containing BRCA1-A can restrain BRCA1’s pro-resection activities at breaks. (julius2019structuralbasisof pages 10-12, julius2020brca1aandbrisc pages 11-13)
BRCA1-A is described as predominantly nuclear, with ABRAXAS1 providing a nuclear import signal required for nuclear localization of the BRCA1-A–BRCA1 assembly. Disruption of this localization (e.g., NLS variants) leads to reduced BRCA1 nuclear localization and foci formation in patient-derived cells. (julius2020brca1aandbrisc pages 3-6, julius2019structuralbasisof pages 1-3, bose2019brca1mislocalizationleads pages 1-3)
A 2023 Cell Death & Disease study identified and functionally dissected two truncating germline ABRAXAS1 variants from early-onset breast cancer patients: c.1106dup (p.Ser370Ilefs2) removing the C-terminal BRCA1-binding SPTF motif, and c.577C>T (p.Arg193) additionally lacking the BRCC36-interaction region while retaining interaction sites for RAP80/MERIT40/BRCC45. (sachsenweger2023abraxas1orchestratesbrca1 pages 3-6, sachsenweger2023abraxas1orchestratesbrca1 pages 8-9)
Key quantitative findings included:
- Mono-allelic ABRAXAS1 mutation did not impair HR proficiency but de-repressed mutagenic pathways such as single-strand annealing (SSA). (sachsenweger2023abraxas1orchestratesbrca1 pages 3-6, sachsenweger2023abraxas1orchestratesbrca1 pages 8-9)
- Baseline DSBR reporter frequencies were reported (HR 3.7×10−4; NHEJ 3.9×10−3; MMEJ 5.3×10−4; SSA 2.5×10−3), enabling quantitative context for pathway shifts. (sachsenweger2023abraxas1orchestratesbrca1 pages 3-6)
- The c.577C>T variant produced strong constitutive DDR phenotypes: 53BP1 up to 12-fold higher versus one comparator, γH2AX ≥6-fold higher untreated and ≥2-fold post-IR, MRE11 increased ~threefold post-IR (basal ~twofold), and RPA increased ≥twofold post-IR (basal ≥fivefold), alongside increased pRPA32 (~twofold by western). (sachsenweger2023abraxas1orchestratesbrca1 pages 3-6)
Mechanistically, the authors interpret these variants as causing dominant effects on BRCA1 complex partitioning (BRCA1-A vs BRCA1-C) and shifting repair pathway usage toward lower-fidelity repair. (sachsenweger2023abraxas1orchestratesbrca1 pages 1-2, sachsenweger2023abraxas1orchestratesbrca1 pages 8-9)
Two key model figures from this study visually summarize (i) which ABRAXAS1 interaction regions are lost in each truncation and (ii) the proposed pathway-rewiring model for DSB repair choice. (sachsenweger2023abraxas1orchestratesbrca1 media db056916, sachsenweger2023abraxas1orchestratesbrca1 media 2aec6fc2)
A 2024 Molecular Systems Biology study used a proteome-scale motif-based interaction approach (GenVar_HD2) and validated that ABRAXAS1 contains a functional NLS disrupted by the R361Q mutation. Quantitatively, the importin/karyopherin interaction affinity weakened about tenfold (wild-type KD = 7.5 μM vs R361Q KD = 75 μM), and the mutant showed more cytoplasmic localization, providing an experimentally tractable molecular explanation consistent with earlier founder-variant cellular phenotypes. (kliche2024proteomescalecharacterisationof pages 11-13)
A multiplexed chromatin-context dependency study of DSB repair proteins reported that BRCA1-A subunits BRCC36 (BRCC3), RAP80 (UIMC1), and BRE (BABAM2) exhibit N-synergies with euchromatic features, and ABRAXAS1 “shows similar patterns but did not pass the significance threshold.” This suggests ABRAXAS1’s influence on pathway balance may be chromatin-context-dependent and is detectable in large-scale functional screens, even if weaker than other BRCA1-A components. (vergara2024widespreadchromatincontextdependencies pages 7-9)
A proteome-wide screen for RNA-dependent proteins in A549 lung cancer cells (R-DeeP) identified 1189 RNA-dependent proteins, including ABRAXAS1, and validated ABRAXAS1 RNA dependence by western blot; importantly, the study reports that direct RNA interaction was verified by iCLIP2 for “the mitosis-related protein ABRAXAS1.” This suggests ABRAXAS1 may participate in RNA-associated complexes or RNA-dependent assemblies in some cell contexts, a direction that could broaden functional annotation beyond canonical BRCA1-A scaffolding. (rajagopal2022proteomewideidentificationof pages 1-2, rajagopal2022proteomewideidentificationof pages 5-7)
ABRAXAS1 has clear relevance to hereditary breast cancer genetics through multiple lines of evidence:
- A Finnish founder germline variant c.1082G>A (p.Arg361Gln; R361Q) lies in the ABRAXAS1 NLS and has functional cellular evidence of impaired nuclear localization and reduced BRCA1 and CtIP nuclear foci formation, supporting pathogenic interpretation in a hereditary cancer context. (bose2019brca1mislocalizationleads pages 1-1, bose2019brca1mislocalizationleads pages 1-3)
- A mechanistic summary of this founder variant reports a mean breast cancer onset age of 46 years (range 35–53) in carriers, comparable to reported Finnish BRCA1/BRCA2 carrier onset ages in that source, providing a clinically interpretable statistic linked to ABRAXAS1. (bose2019molecularandfunctional pages 56-59)
- The 2023 truncation study provides functional evidence that heterozygous truncations can exert dominant-negative effects via complex rewiring and increased low-fidelity DSBR pathway usage, implying that ABRAXAS1 variant interpretation should consider pathway balance (SSA/MMEJ/NHEJ derepression) rather than only classic HR loss. (sachsenweger2023abraxas1orchestratesbrca1 pages 1-2, sachsenweger2023abraxas1orchestratesbrca1 pages 3-6)
A clinically important negative result from the 2023 truncation study is that heterozygous ABRAXAS1 mutation carriers did not show haploinsufficiency for HR proficiency by several assays and did not show altered PARP-inhibitor sensitivity, despite evidence of mutagenic pathway derepression and DDR abnormalities. This suggests ABRAXAS1 variants may not automatically confer a “BRCA-like” homologous recombination deficiency phenotype in the heterozygous state, limiting immediate extrapolation to PARP inhibitor eligibility based solely on ABRAXAS1 carrier status. (sachsenweger2023abraxas1orchestratesbrca1 pages 1-2, sachsenweger2023abraxas1orchestratesbrca1 pages 8-9)
Open Targets reports disease associations for ABRAXAS1 including breast carcinoma/breast cancer, ovarian dysfunction, and inherited cancer-predisposing syndromes, with evidence entries linked to literature and variant records. This supports its placement among cancer predisposition/DDR-associated genes in biomedical databases. (OpenTargets Search: -ABRAXAS1,FAM175A,CCDC98)
A consistent interpretation across high-quality structural work and reviews is that ABRAXAS1 (BRCA1-A) and ABRO1 (BRISC) are subcomplex-specific “functionalizers” of the same BRCC36 DUB core: they determine compartmentalization, recruitment to specific ubiquitin/SUMO marks, and regulatory constraints, while BRCC36 supplies the K63-specific catalytic activity. This adaptor-driven specialization model is central for functional annotation and for reasoning about phenotypes of ABRAXAS1 variants. (julius2020brca1aandbrisc pages 1-3, julius2019structuralbasisof pages 10-12)
The recent 2023 patient-derived work emphasizes that truncations lacking the BRCA1-binding C-terminus can retain interaction capacity for other BRCA1-A partners (e.g., RAP80), plausibly allowing dominant complex perturbation rather than simple loss-of-function. This “rewiring” concept helps explain why some heterozygous ABRAXAS1 variants alter pathway choice without producing strong HRD signatures and why functional studies are needed for variant classification. (sachsenweger2023abraxas1orchestratesbrca1 pages 1-2)
References
(julius2020brca1aandbrisc pages 1-3): Julius Rabl. Brca1-a and brisc: multifunctional molecular machines for ubiquitin signaling. Biomolecules, Oct 2020. URL: https://doi.org/10.3390/biom10111503, doi:10.3390/biom10111503. This article has 33 citations.
(bose2019brca1mislocalizationleads pages 1-3): Muthiah Bose, Juliane Sachsenweger, Niina Laurila, Ann Christin Parplys, Jonas Willmann, Johannes Jungwirth, Marco Groth, Katrin Rapakko, Pentti Nieminen, Thomas W P Friedl, Lisa Heiserich, Felix Meyer, Hanna Tuppurainen, Hellevi Peltoketo, Heli Nevanlinna, Katri Pylkäs, Kerstin Borgmann, Lisa Wiesmüller, Robert Winqvist, and Helmut Pospiech. Brca1 mislocalization leads to aberrant dna damage response in heterozygous abraxas1 mutation carrier cells. Human molecular genetics, Dec 2019. URL: https://doi.org/10.1093/hmg/ddz252, doi:10.1093/hmg/ddz252. This article has 11 citations and is from a domain leading peer-reviewed journal.
(julius2020brca1aandbrisc pages 3-6): Julius Rabl. Brca1-a and brisc: multifunctional molecular machines for ubiquitin signaling. Biomolecules, Oct 2020. URL: https://doi.org/10.3390/biom10111503, doi:10.3390/biom10111503. This article has 33 citations.
(kyrieleis2016threedimensionalarchitectureof pages 3-4): Otto J.P. Kyrieleis, Pauline B. McIntosh, Sarah R. Webb, Lesley J. Calder, Janette Lloyd, Nisha A. Patel, Stephen R. Martin, Carol V. Robinson, Peter B. Rosenthal, and Stephen J. Smerdon. Three-dimensional architecture of the human brca1-a histone deubiquitinase core complex. Cell Reports, 17:3099-3106, Dec 2016. URL: https://doi.org/10.1016/j.celrep.2016.11.063, doi:10.1016/j.celrep.2016.11.063. This article has 28 citations and is from a highest quality peer-reviewed journal.
(sachsenweger2023abraxas1orchestratesbrca1 pages 1-2): Juliane Sachsenweger, Rebecca Jansche, Tatjana Merk, Benedikt Heitmeir, Miriam Deniz, Ulrike Faust, Cristiana Roggia, Andreas Tzschach, Christopher Schroeder, Angelika Riess, Helmut Pospiech, Hellevi Peltoketo, Katri Pylkäs, Robert Winqvist, and Lisa Wiesmüller. Abraxas1 orchestrates brca1 activities to counter genome destabilizing repair pathways—lessons from breast cancer patients. Cell Death & Disease, May 2023. URL: https://doi.org/10.1038/s41419-023-05845-6, doi:10.1038/s41419-023-05845-6. This article has 10 citations and is from a peer-reviewed journal.
(sachsenweger2023abraxas1orchestratesbrca1 pages 8-9): Juliane Sachsenweger, Rebecca Jansche, Tatjana Merk, Benedikt Heitmeir, Miriam Deniz, Ulrike Faust, Cristiana Roggia, Andreas Tzschach, Christopher Schroeder, Angelika Riess, Helmut Pospiech, Hellevi Peltoketo, Katri Pylkäs, Robert Winqvist, and Lisa Wiesmüller. Abraxas1 orchestrates brca1 activities to counter genome destabilizing repair pathways—lessons from breast cancer patients. Cell Death & Disease, May 2023. URL: https://doi.org/10.1038/s41419-023-05845-6, doi:10.1038/s41419-023-05845-6. This article has 10 citations and is from a peer-reviewed journal.
(kliche2024proteomescalecharacterisationof pages 11-13): Johanna Kliche, Leandro Simonetti, Izabella Krystkowiak, Hanna Kuss, Marcel Diallo, Emma Rask, Jakob Nilsson, Norman E Davey, and Ylva Ivarsson. Proteome-scale characterisation of motif-based interactome rewiring by disease mutations. Molecular Systems Biology, 20:1025-1048, Jul 2024. URL: https://doi.org/10.1038/s44320-024-00055-4, doi:10.1038/s44320-024-00055-4. This article has 23 citations and is from a highest quality peer-reviewed journal.
(julius2020brca1aandbrisc pages 11-13): Julius Rabl. Brca1-a and brisc: multifunctional molecular machines for ubiquitin signaling. Biomolecules, Oct 2020. URL: https://doi.org/10.3390/biom10111503, doi:10.3390/biom10111503. This article has 33 citations.
(sachsenweger2023abraxas1orchestratesbrca1 pages 12-13): Juliane Sachsenweger, Rebecca Jansche, Tatjana Merk, Benedikt Heitmeir, Miriam Deniz, Ulrike Faust, Cristiana Roggia, Andreas Tzschach, Christopher Schroeder, Angelika Riess, Helmut Pospiech, Hellevi Peltoketo, Katri Pylkäs, Robert Winqvist, and Lisa Wiesmüller. Abraxas1 orchestrates brca1 activities to counter genome destabilizing repair pathways—lessons from breast cancer patients. Cell Death & Disease, May 2023. URL: https://doi.org/10.1038/s41419-023-05845-6, doi:10.1038/s41419-023-05845-6. This article has 10 citations and is from a peer-reviewed journal.
(julius2020brca1aandbrisc pages 8-11): Julius Rabl. Brca1-a and brisc: multifunctional molecular machines for ubiquitin signaling. Biomolecules, Oct 2020. URL: https://doi.org/10.3390/biom10111503, doi:10.3390/biom10111503. This article has 33 citations.
(kyrieleis2016threedimensionalarchitectureof pages 1-3): Otto J.P. Kyrieleis, Pauline B. McIntosh, Sarah R. Webb, Lesley J. Calder, Janette Lloyd, Nisha A. Patel, Stephen R. Martin, Carol V. Robinson, Peter B. Rosenthal, and Stephen J. Smerdon. Three-dimensional architecture of the human brca1-a histone deubiquitinase core complex. Cell Reports, 17:3099-3106, Dec 2016. URL: https://doi.org/10.1016/j.celrep.2016.11.063, doi:10.1016/j.celrep.2016.11.063. This article has 28 citations and is from a highest quality peer-reviewed journal.
(julius2019structuralbasisof pages 10-12): Julius Rabl, Richard D. Bunker, Andreas D. Schenk, Simone Cavadini, Mark E. Gill, Wassim Abdulrahman, Amparo Andrés-Pons, Martijn S. Luijsterburg, Adel F. M. Ibrahim, Emma Branigan, Jacob D. Aguirre, Aimee H. Marceau, Claire Guérillon, Tewis Bouwmeester, Ulrich Hassiepen, Antoine H.F.M. Peters, Martin Renatus, Laurent Gelman, Seth M. Rubin, Niels Mailand, Haico van Attikum, Ronald T. Hay, and Nicolas H. Thomä. Structural basis of brcc36 function in dna repair and immune regulation. Molecular Cell, 75:483-497.e9, Aug 2019. URL: https://doi.org/10.1016/j.molcel.2019.06.002, doi:10.1016/j.molcel.2019.06.002. This article has 86 citations and is from a highest quality peer-reviewed journal.
(julius2019structuralbasisof pages 1-3): Julius Rabl, Richard D. Bunker, Andreas D. Schenk, Simone Cavadini, Mark E. Gill, Wassim Abdulrahman, Amparo Andrés-Pons, Martijn S. Luijsterburg, Adel F. M. Ibrahim, Emma Branigan, Jacob D. Aguirre, Aimee H. Marceau, Claire Guérillon, Tewis Bouwmeester, Ulrich Hassiepen, Antoine H.F.M. Peters, Martin Renatus, Laurent Gelman, Seth M. Rubin, Niels Mailand, Haico van Attikum, Ronald T. Hay, and Nicolas H. Thomä. Structural basis of brcc36 function in dna repair and immune regulation. Molecular Cell, 75:483-497.e9, Aug 2019. URL: https://doi.org/10.1016/j.molcel.2019.06.002, doi:10.1016/j.molcel.2019.06.002. This article has 86 citations and is from a highest quality peer-reviewed journal.
(kyrieleis2016threedimensionalarchitectureof pages 5-6): Otto J.P. Kyrieleis, Pauline B. McIntosh, Sarah R. Webb, Lesley J. Calder, Janette Lloyd, Nisha A. Patel, Stephen R. Martin, Carol V. Robinson, Peter B. Rosenthal, and Stephen J. Smerdon. Three-dimensional architecture of the human brca1-a histone deubiquitinase core complex. Cell Reports, 17:3099-3106, Dec 2016. URL: https://doi.org/10.1016/j.celrep.2016.11.063, doi:10.1016/j.celrep.2016.11.063. This article has 28 citations and is from a highest quality peer-reviewed journal.
(sachsenweger2023abraxas1orchestratesbrca1 pages 3-6): Juliane Sachsenweger, Rebecca Jansche, Tatjana Merk, Benedikt Heitmeir, Miriam Deniz, Ulrike Faust, Cristiana Roggia, Andreas Tzschach, Christopher Schroeder, Angelika Riess, Helmut Pospiech, Hellevi Peltoketo, Katri Pylkäs, Robert Winqvist, and Lisa Wiesmüller. Abraxas1 orchestrates brca1 activities to counter genome destabilizing repair pathways—lessons from breast cancer patients. Cell Death & Disease, May 2023. URL: https://doi.org/10.1038/s41419-023-05845-6, doi:10.1038/s41419-023-05845-6. This article has 10 citations and is from a peer-reviewed journal.
(sachsenweger2023abraxas1orchestratesbrca1 media db056916): Juliane Sachsenweger, Rebecca Jansche, Tatjana Merk, Benedikt Heitmeir, Miriam Deniz, Ulrike Faust, Cristiana Roggia, Andreas Tzschach, Christopher Schroeder, Angelika Riess, Helmut Pospiech, Hellevi Peltoketo, Katri Pylkäs, Robert Winqvist, and Lisa Wiesmüller. Abraxas1 orchestrates brca1 activities to counter genome destabilizing repair pathways—lessons from breast cancer patients. Cell Death & Disease, May 2023. URL: https://doi.org/10.1038/s41419-023-05845-6, doi:10.1038/s41419-023-05845-6. This article has 10 citations and is from a peer-reviewed journal.
(rajagopal2022proteomewideidentificationof pages 1-2): Varshni Rajagopal, Astrid-Solveig Loubal, Niklas Engel, Elsa Wassmer, Jeanette Seiler, Oliver Schilling, Maiwen Caudron-Herger, and Sven Diederichs. Proteome-wide identification of rna-dependent proteins in lung cancer cells. Cancers, 14:6109, Dec 2022. URL: https://doi.org/10.3390/cancers14246109, doi:10.3390/cancers14246109. This article has 8 citations.
(rajagopal2022proteomewideidentificationof pages 5-7): Varshni Rajagopal, Astrid-Solveig Loubal, Niklas Engel, Elsa Wassmer, Jeanette Seiler, Oliver Schilling, Maiwen Caudron-Herger, and Sven Diederichs. Proteome-wide identification of rna-dependent proteins in lung cancer cells. Cancers, 14:6109, Dec 2022. URL: https://doi.org/10.3390/cancers14246109, doi:10.3390/cancers14246109. This article has 8 citations.
(sachsenweger2023abraxas1orchestratesbrca1 media 2aec6fc2): Juliane Sachsenweger, Rebecca Jansche, Tatjana Merk, Benedikt Heitmeir, Miriam Deniz, Ulrike Faust, Cristiana Roggia, Andreas Tzschach, Christopher Schroeder, Angelika Riess, Helmut Pospiech, Hellevi Peltoketo, Katri Pylkäs, Robert Winqvist, and Lisa Wiesmüller. Abraxas1 orchestrates brca1 activities to counter genome destabilizing repair pathways—lessons from breast cancer patients. Cell Death & Disease, May 2023. URL: https://doi.org/10.1038/s41419-023-05845-6, doi:10.1038/s41419-023-05845-6. This article has 10 citations and is from a peer-reviewed journal.
(vergara2024widespreadchromatincontextdependencies pages 7-9): Xabier Vergara, Anna G. Manjón, Ben Morris, Ruben Schep, Christ Leemans, Mathijs A. Sanders, Roderick L. Beijersbergen, René H. Medema, and Bas van Steensel. Widespread chromatin context-dependencies of dna double-strand break repair proteins. Nature Communications, Oct 2024. URL: https://doi.org/10.1101/2022.10.07.511243, doi:10.1101/2022.10.07.511243. This article has 25 citations and is from a highest quality peer-reviewed journal.
(bose2019brca1mislocalizationleads pages 1-1): Muthiah Bose, Juliane Sachsenweger, Niina Laurila, Ann Christin Parplys, Jonas Willmann, Johannes Jungwirth, Marco Groth, Katrin Rapakko, Pentti Nieminen, Thomas W P Friedl, Lisa Heiserich, Felix Meyer, Hanna Tuppurainen, Hellevi Peltoketo, Heli Nevanlinna, Katri Pylkäs, Kerstin Borgmann, Lisa Wiesmüller, Robert Winqvist, and Helmut Pospiech. Brca1 mislocalization leads to aberrant dna damage response in heterozygous abraxas1 mutation carrier cells. Human molecular genetics, Dec 2019. URL: https://doi.org/10.1093/hmg/ddz252, doi:10.1093/hmg/ddz252. This article has 11 citations and is from a domain leading peer-reviewed journal.
(bose2019molecularandfunctional pages 56-59): M Bose. Molecular and functional characterization of abraxas and palb2 genes in hereditary breast cancer predisposition. Unknown journal, 2019.
(OpenTargets Search: -ABRAXAS1,FAM175A,CCDC98): Open Targets Query (-ABRAXAS1,FAM175A,CCDC98, 5 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
(kliche2024proteomescalecharacterisationof pages 1-2): Johanna Kliche, Leandro Simonetti, Izabella Krystkowiak, Hanna Kuss, Marcel Diallo, Emma Rask, Jakob Nilsson, Norman E Davey, and Ylva Ivarsson. Proteome-scale characterisation of motif-based interactome rewiring by disease mutations. Molecular Systems Biology, 20:1025-1048, Jul 2024. URL: https://doi.org/10.1038/s44320-024-00055-4, doi:10.1038/s44320-024-00055-4. This article has 23 citations and is from a highest quality peer-reviewed journal.
just fetch-gene human ABRAXAS1 seeded the UniProt, GOA, Reactome, PANTHER family, and review stub files on 2026-06-03.just deep-research-falcon human ABRAXAS1 --fallback perplexity-lite. Falcon timed out after 600 seconds; the perplexity-lite fallback then failed with a Perplexity API 401 quota error. No provider deep-research file was produced, so this review uses cached publications, UniProt, Reactome, PANTHER, and PN projection files directly.ABRAXAS1/FAM175A/CCDC98 is a nuclear BRCA1-A complex scaffold and ubiquitin-recognition subunit. The primary literature identifies Abraxas as a BRCA1 BRCT-binding phosphoprotein and RAP80 partner: PMID:17525340 and PMID:17525340.
The supported biological role is DNA double-strand break response and checkpoint/repair signaling, not a standalone catalytic activity. The key experimental summary is that PMID:17525340. A second study frames CCDC98 as the factor that mediates BRCA1-RAP80 association and BRCA1-dependent G2/M checkpoint activation PMID:17643121.
ABRAXAS1 is also an organizer of the RAP80/BRCA1-A complex. Feng et al. describe CCDC98 as central to assembly: PMID:19261748. The BRCA1-A/RAP80 complex has BRCC36 K63-linked deubiquitinase activity, but the catalytic subunit is BRCC36, while Abraxas is required for that activity in the RAP80 complex context PMID:20656689.
The PN projection has three ABRAXAS1 rows:
GO:0070531 BRCA1-A complex: already exact in GOA and accepted.GO:0006281 DNA repair: already entailed by GOA via GO:0006302 double-strand break repair, so no new annotation is needed.GO:0000151 ubiquitin ligase complex: new to GOA from the PN group Ubiquitin Proteasome System|E3 ubiquitin and UBL ligases|idiosyncratic RING complex. I did not add this as a proposed annotation. ABRAXAS1 is part of BRCA1-A, but the gene-level evidence supports scaffold/polyubiquitin-binding and BRCC36 DUB support rather than direct membership in a generic ubiquitin ligase complex. The PN mapping itself says this is a shared E3-complex bucket and warns against assigning catalytic activity to every subunit.protein binding rows are real interaction evidence but too uninformative for core molecular function. Mechanistic papers should be interpreted as BRCA1-A complex assembly, RAP80/BRCA1/BRCC36 interaction, and polyubiquitin-dependent recruitment rather than retained as generic protein binding.WITH/FROM: UniProtKB:Q15018) rather than ABRAXAS1-specific evidence. I marked microtubule binding, attachment of spindle microtubules to kinetochore, and mitotic spindle assembly for removal for ABRAXAS1.A Falcon deep-research report (ABRAXAS1-deep-research-falcon.md, Edison Scientific) was generated successfully on 2026-06-07, superseding the earlier failed run noted above. It is consistent with the existing review and adds the following, with NEW/CONFIRMS/PROVISIONAL labels. PMIDs could not be resolved via tooling for several of these primary papers (PubMed MCP unavailable); where only a DOI was available it is given, and these citations are kept in notes only rather than added as guessed PMIDs to the YAML.
CONFIRMS (molecular function / mechanism): ABRAXAS1 is a non-catalytic scaffold/adaptor with an N-terminal MPN-/JAMM-like domain that is catalytically inactive (MPN-) and acts as a DEUBAD-like activator/positioner of the K63-specific DUB BRCC36; ABRAXAS1 itself does not deubiquitinate. This matches the existing KEEP polyubiquitin-binding / not the catalytic DUB framing [PMID:20656689 "Abraxas and BRCC45 were essential for BRCC36 DUB activity within the RAP80 complex"; Rabl 2020 review doi:10.3390/biom10111503; Kyrieleis 2016 doi:10.1016/j.celrep.2016.11.063].
NEW (structural architecture): Negative-stain EM of a reconstituted human BRCA1-A core (Abraxas/BRCC36/BRCC45/MERIT40) supports a V-shaped "superdimer" (dimer of heterotetramers) with ABRAXAS1-BRCC36 at the base and BRCC45/MERIT40 in the arms; complexes prefer longer K63 chains (>=4 Ub), and RAP80 enhances targeting to mixed SUMO-K63 chains [Kyrieleis 2016 doi:10.1016/j.celrep.2016.11.063; Rabl 2019 Mol Cell doi:10.1016/j.molcel.2019.06.002]. Adds structural detail beyond current complex-membership annotations; no annotation change warranted.
NEW (domain map / NLS, clinical): ABRAXAS1 has an NLS (~aa 358-361, incl. Arg361) required for nuclear import of BRCA1-A; the Finnish founder variant c.1082G>A p.Arg361Gln (R361Q) impairs nuclear localization and reduces BRCA1/CtIP foci [Bose 2019 Hum Mol Genet doi:10.1093/hmg/ddz252]. A 2024 motif-interactome study (already cited as PMID:39009827) quantified the R361Q effect: importin/karyopherin affinity weakened ~10-fold (WT KD 7.5 uM vs R361Q 75 uM) with increased cytoplasmic localization PMID:39009827. The C-terminal pSPxF/SPTF motif (~aa 406-409; S404 damage-inducible, S406 constitutive, F409 critical) mediates phospho-dependent BRCA1 BRCT binding.
NEW (disease mechanism / pathway choice): Two truncating germline ABRAXAS1 variants from early-onset breast cancer patients - c.1106dup (p.Ser370Ilefs2, loses the C-terminal BRCA1-binding SPTF motif) and c.577C>T (p.Arg193, also lacks the BRCC36-interaction region) - act dominantly to shift BRCA1 partitioning from BRCA1-A toward BRCA1-C and derepress mutagenic DSB repair (SSA/MMEJ/NHEJ) without impairing HR; notably heterozygous carriers did NOT show HR deficiency or altered PARP-inhibitor sensitivity [Sachsenweger 2023 Cell Death Dis doi:10.1038/s41419-023-05845-6]. Reframes ABRAXAS1 as a "fine-tuner" of BRCA1 repair-pathway choice (restrains end resection / mutagenic pathways) rather than a simple HR-promoting factor. Supports the existing positive regulation of DNA repair / checkpoint framing; no existing annotation contradicted.
PROVISIONAL / low-confidence (RNA association): A proteome-wide R-DeeP screen in A549 lung cancer cells identified ABRAXAS1 as RNA-dependent, with direct RNA interaction validated by iCLIP2 ("mitosis-related protein ABRAXAS1") [Rajagopal 2022 Cancers doi:10.3390/cancers14246109]. This is a single high-throughput study in one cell line; flagged provisional and NOT used to add any RNA-binding GO annotation. Worth a curator question only.
CONFIRMS (paralog specialization): ABRAXAS1 (BRCA1-A, nuclear) vs paralog ABRO1/ABRAXAS2 (BRISC, largely non-nuclear) partition the shared BRCC36/BRE/MERIT40 core. This reinforces the existing REMOVE decisions on microtubule/spindle IBA terms traceable to ABRAXAS2 [Rabl 2020 doi:10.3390/biom10111503; Rabl 2019 doi:10.1016/j.molcel.2019.06.002].
UPS|E3 ubiquitin and UBL ligases|idiosyncratic RING complex|BRCA1-A complex|ubiquitin binding AND UPS|Ubiquitin and UBL binding|DNA repair|BRCA1-A complex component|idiosyncratic Ub binding / MPN ; PN-node mapping: type BRCA1-A complex=mapped→GO:0070531 (already_in_goa_exact); group idiosyncratic RING complex=mapped→GO:0000151 ubiquitin ligase complex (new_to_goa); group ...|DNA repair=mapped→GO:0006281 DNA repair (entailed_by_goa_closure); class E3...ligases/Ub and UBL binding=context_only; branch UPS=no_mapping.This file is generated from the current PROTEOSTASIS phase-1 dossier and local gene-review artifacts. Edit the source review, PN mapping, or dossier rather than this generated note when correcting the underlying curation.
id: Q6UWZ7
gene_symbol: ABRAXAS1
product_type: PROTEIN
status: DRAFT
taxon:
id: NCBITaxon:9606
label: Homo sapiens
description: >-
ABRAXAS1 encodes a nuclear BRCA1-A complex subunit that acts as a scaffold linking BRCA1, UIMC1/RAP80, BRCC3/BRCC36,
BABAM proteins, and ubiquitin-dependent DNA damage-site signaling. The protein contains an MPN-like domain, binds
polyubiquitin as part of the BRCA1-A/RAP80 complex, and supports BRCA1 recruitment, DNA double-strand break repair,
K63-ubiquitin signal editing by BRCC36, and G2/M DNA damage checkpoint responses.
alternative_products:
- name: '1'
id: Q6UWZ7-1
- name: '2'
id: Q6UWZ7-2
sequence_note: VSP_058196
existing_annotations:
- term:
id: GO:0005634
label: nucleus
evidence_type: IBA
original_reference_id: GO_REF:0000033
qualifier: is_active_in
review:
summary: >-
Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage
sites within the nucleus.
action: ACCEPT
reason: >-
The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes
BRCA1-A complex activity at DNA double-strand breaks.
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121,
ECO:0000269|PubMed:17643122}.
- reference_id: PMID:17525340
supporting_text: RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response
to ionizing radiation
- term:
id: GO:0008017
label: microtubule binding
evidence_type: IBA
original_reference_id: GO_REF:0000033
qualifier: enables
review:
summary: >-
Likely paralog/family over-propagation. The IBA trace for this microtubule-binding term cites ABRAXAS2 rather
than ABRAXAS1-specific evidence.
action: REMOVE
reason: >-
ABRAXAS1 literature, UniProt, Reactome, and PN context support a nuclear BRCA1-A DNA damage-response scaffold,
not microtubule binding. No ABRAXAS1-specific microtubule-binding evidence was found in the cached evidence
set.
additional_reference_ids:
- file:interpro/panther/PTHR31728/PTHR31728-entries.csv
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Involved in DNA damage response and double-strand break (DSB) repair.
- reference_id: file:human/ABRAXAS1/ABRAXAS1-notes.md
supporting_text: The IBA microtubule/spindle annotations are projected through a PANTHER node supported
by ABRAXAS2
- term:
id: GO:0008608
label: attachment of spindle microtubules to kinetochore
evidence_type: IBA
original_reference_id: GO_REF:0000033
qualifier: involved_in
review:
summary: >-
Likely paralog/family over-propagation. The kinetochore-microtubule attachment IBA is not supported by ABRAXAS1-specific
DNA damage literature.
action: REMOVE
reason: >-
The with/from metadata points to ABRAXAS2 for the spindle branch, while ABRAXAS1 evidence supports BRCA1-A
complex-mediated DNA damage signaling. This process would overstate ABRAXAS1 biology.
additional_reference_ids:
- file:interpro/panther/PTHR31728/PTHR31728-entries.csv
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Involved in DNA damage response and double-strand break (DSB) repair.
- reference_id: file:human/ABRAXAS1/ABRAXAS1-notes.md
supporting_text: I marked `microtubule binding`, `attachment of spindle microtubules to kinetochore`,
and `mitotic spindle assembly` for removal for ABRAXAS1.
- term:
id: GO:0031593
label: polyubiquitin modification-dependent protein binding
evidence_type: IBA
original_reference_id: GO_REF:0000033
qualifier: enables
review:
summary: >-
Core molecular function. ABRAXAS1 is part of a BRCA1-A/RAP80 complex that recognizes ubiquitinated damage-site
chromatin and has polyubiquitin-binding capacity.
action: ACCEPT
reason: >-
The term captures the ubiquitin-recognition side of ABRAXAS1 biology better than generic protein binding.
It should be retained for both direct IDA and IBA evidence.
supported_by:
- reference_id: PMID:19261749
supporting_text: four members of the BRCA1-A complex possess a polyubiquitin chain-binding capability
- reference_id: PMID:20656689
supporting_text: RAP80, in turn, is recruited to DSBs through its tandem ubiquitin-interacting motifs
(UIMs) ( 6 , 14 – 16 ), which specifically recognize K63-Ub chains
- term:
id: GO:0090307
label: mitotic spindle assembly
evidence_type: IBA
original_reference_id: GO_REF:0000033
qualifier: involved_in
review:
summary: >-
Likely paralog/family over-propagation. The mitotic-spindle-assembly IBA is not supported for ABRAXAS1 by
the reviewed evidence.
action: REMOVE
reason: >-
ABRAXAS1 participates in nuclear DNA damage repair/checkpoint signaling. The PANTHER IBA spindle call is traceable
to ABRAXAS2 and should not be propagated to ABRAXAS1 without gene-specific evidence.
additional_reference_ids:
- file:interpro/panther/PTHR31728/PTHR31728-entries.csv
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Involved in DNA damage response and double-strand break (DSB) repair.
- reference_id: file:human/ABRAXAS1/ABRAXAS1-notes.md
supporting_text: I marked `microtubule binding`, `attachment of spindle microtubules to kinetochore`,
and `mitotic spindle assembly` for removal for ABRAXAS1.
- term:
id: GO:0005634
label: nucleus
evidence_type: IEA
original_reference_id: GO_REF:0000044
qualifier: located_in
review:
summary: >-
Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage
sites within the nucleus.
action: ACCEPT
reason: >-
The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes
BRCA1-A complex activity at DNA double-strand breaks.
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121,
ECO:0000269|PubMed:17643122}.
- reference_id: PMID:17525340
supporting_text: RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response
to ionizing radiation
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:17525340
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:17525340
supporting_text: identified a protein, Abraxas, that directly binds the BRCA1 BRCT repeats
- reference_id: PMID:20656689
supporting_text: The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36,
BRCC45, Abraxas, and MERIT40
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:17643121
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:17643121
supporting_text: CCDC98 is a BRCA1 binding partner that mediates BRCA1 function in response to DNA
damage.
- reference_id: PMID:20656689
supporting_text: The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36,
BRCC45, Abraxas, and MERIT40
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:18077395
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:18077395
supporting_text: Rap80 contains an Abraxas interaction domain
- reference_id: PMID:20656689
supporting_text: The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36,
BRCC45, Abraxas, and MERIT40
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:19615732
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:19615732
supporting_text: We identified 774 candidate interacting proteins associated with 75 Dubs.
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:29656893
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:29656893
supporting_text: we generated high-resolution interaction neighborhood maps of the endogenously
expressed DNA repair factors 53BP1, BRCA1, and MDC1
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:34591612
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:34591612
supporting_text: we generated comprehensive interaction maps for 40 frequently altered BC proteins
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:35156780
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:35156780
supporting_text: high-throughput screening variant of the Mammalian Membrane Two-Hybrid
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:36012204
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:36012204
supporting_text: proximity labeling approaches identified both known and additional CFTR protein
partners
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:39009827
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:39009827
supporting_text: we identified 366 mutation-modulated interactions
- term:
id: GO:0016604
label: nuclear body
evidence_type: IDA
original_reference_id: GO_REF:0000052
qualifier: located_in
review:
summary: >-
Non-core localization. HPA reports nuclear-body staining, while mechanistic ABRAXAS1 biology centers on DNA
damage foci/BRCA1-A complex recruitment.
action: KEEP_AS_NON_CORE
reason: >-
This cellular component is plausible as a localization observation, but it is less informative than nucleus/nucleoplasm
and BRCA1-A complex membership for the gene product function.
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Localizes at sites of DNA damage at double-strand breaks (DSBs).
- term:
id: GO:0005634
label: nucleus
evidence_type: NAS
original_reference_id: PMID:20656689
qualifier: located_in
review:
summary: >-
Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage
sites within the nucleus.
action: ACCEPT
reason: >-
The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes
BRCA1-A complex activity at DNA double-strand breaks.
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121,
ECO:0000269|PubMed:17643122}.
- reference_id: PMID:17525340
supporting_text: RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response
to ionizing radiation
- term:
id: GO:0006282
label: regulation of DNA repair
evidence_type: NAS
original_reference_id: PMID:20656689
qualifier: involved_in
review:
summary: >-
The broad regulation-of-DNA-repair annotation is directionally correct but less precise than positive regulation
of DNA repair for ABRAXAS1.
action: MODIFY
reason: >-
ABRAXAS1 promotes BRCA1-A complex recruitment/stability and DNA repair after damage; the reviewed IMP annotations
already use the more informative positive-regulation term.
proposed_replacement_terms:
- id: GO:0045739
label: positive regulation of DNA repair
supported_by:
- reference_id: PMID:17525340
supporting_text: Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint
control, and DNA repair.
- reference_id: PMID:19261748
supporting_text: a stable complex containing MERIT40 acts early in DNA damage response and regulates
damage-dependent BRCA1 localization
- term:
id: GO:0044818
label: mitotic G2/M transition checkpoint
evidence_type: NAS
original_reference_id: PMID:22369660
qualifier: involved_in
review:
summary: >-
The ComplexPortal/NAS checkpoint annotation is real but should be represented using the more specific DNA-damage
checkpoint signaling term.
action: MODIFY
reason: >-
ABRAXAS1 evidence concerns BRCA1-dependent G2/M checkpoint activation in response to DNA damage, not the generic
mitotic G2/M transition checkpoint.
proposed_replacement_terms:
- id: GO:0007095
label: mitotic G2 DNA damage checkpoint signaling
supported_by:
- reference_id: PMID:17643121
supporting_text: CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent
G2/M checkpoint activation
- reference_id: PMID:22369660
supporting_text: Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out
functions of BRCA1 in cell cycle checkpoint control.
- term:
id: GO:0070531
label: BRCA1-A complex
evidence_type: NAS
original_reference_id: PMID:20656689
qualifier: part_of
review:
summary: >-
Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36,
BABAM proteins, and related DDR functions.
action: ACCEPT
reason: >-
Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more
precise than the PN-projected generic ubiquitin-ligase-complex bucket.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
- file:projects/PROTEOSTASIS/mappings/ubiquitin_proteasome_system.yaml
supported_by:
- reference_id: PMID:19261749
supporting_text: Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also
contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0007095
label: mitotic G2 DNA damage checkpoint signaling
evidence_type: IMP
original_reference_id: PMID:17525340
qualifier: involved_in
review:
summary: >-
Core checkpoint process. ABRAXAS1/CCDC98 is required for BRCA1-dependent G2/M checkpoint signaling after DNA
damage.
action: ACCEPT
reason: >-
The original ABRAXAS1/CCDC98 work and later BRCA1-A review evidence support a G2 DNA damage checkpoint role.
This is part of the DNA damage response function rather than a general mitotic-spindle role.
supported_by:
- reference_id: PMID:17643121
supporting_text: CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent
G2/M checkpoint activation
- reference_id: PMID:22369660
supporting_text: Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out
functions of BRCA1 in cell cycle checkpoint control.
- term:
id: GO:0007095
label: mitotic G2 DNA damage checkpoint signaling
evidence_type: IMP
original_reference_id: PMID:17643121
qualifier: involved_in
review:
summary: >-
Core checkpoint process. ABRAXAS1/CCDC98 is required for BRCA1-dependent G2/M checkpoint signaling after DNA
damage.
action: ACCEPT
reason: >-
The original ABRAXAS1/CCDC98 work and later BRCA1-A review evidence support a G2 DNA damage checkpoint role.
This is part of the DNA damage response function rather than a general mitotic-spindle role.
supported_by:
- reference_id: PMID:17643121
supporting_text: CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent
G2/M checkpoint activation
- reference_id: PMID:22369660
supporting_text: Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out
functions of BRCA1 in cell cycle checkpoint control.
- term:
id: GO:0007095
label: mitotic G2 DNA damage checkpoint signaling
evidence_type: IMP
original_reference_id: PMID:19261748
qualifier: involved_in
review:
summary: >-
Core checkpoint process. ABRAXAS1/CCDC98 is required for BRCA1-dependent G2/M checkpoint signaling after DNA
damage.
action: ACCEPT
reason: >-
The original ABRAXAS1/CCDC98 work and later BRCA1-A review evidence support a G2 DNA damage checkpoint role.
This is part of the DNA damage response function rather than a general mitotic-spindle role.
supported_by:
- reference_id: PMID:17643121
supporting_text: CCDC98 controls both DNA damage-induced formation of BRCA1 foci and BRCA1-dependent
G2/M checkpoint activation
- reference_id: PMID:22369660
supporting_text: Studies on A, B and C complexes of BRCA1 indicate that these complexes carry out
functions of BRCA1 in cell cycle checkpoint control.
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5683384
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5683385
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5683735
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5683801
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5684052
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5684071
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5686685
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5691411
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-5693551
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005654
label: nucleoplasm
evidence_type: TAS
original_reference_id: Reactome:R-HSA-69891
qualifier: located_in
review:
summary: >-
Supported Reactome-derived nuclear compartment annotation. The BRCA1-A complex events involving FAM175A/ABRAXAS1
are modeled at nuclear DNA double-strand breaks.
action: ACCEPT
reason: >-
The nucleoplasm location is consistent with ABRAXAS1 nuclear localization and Reactome DNA double-strand break
events. These duplicate TAS rows reflect pathway-event participation rather than distinct localizations.
supported_by:
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:19261748
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:19261748
supporting_text: CCDC98 binds to RAP80 via a large N-terminal region
- reference_id: PMID:20656689
supporting_text: The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36,
BRCC45, Abraxas, and MERIT40
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:19261749
qualifier: enables
review:
summary: >-
Interaction evidence is real, but the GO term protein binding is too generic to describe ABRAXAS1 function.
action: MARK_AS_OVER_ANNOTATED
reason: >-
These IPI rows should not be treated as core molecular-function annotations. The informative biology is BRCA1-A
complex assembly, RAP80/BRCA1/BRCC36 interactions, and polyubiquitin-dependent recruitment; broad interactome
rows are even less suitable as function claims.
supported_by:
- reference_id: PMID:19261749
supporting_text: four members of the BRCA1-A complex possess a polyubiquitin chain-binding capability
- reference_id: PMID:20656689
supporting_text: The RAP80 complex is a five-member stoichiometric complex consisting of RAP80, BRCC36,
BRCC45, Abraxas, and MERIT40
- term:
id: GO:0005634
label: nucleus
evidence_type: IDA
original_reference_id: PMID:17525340
qualifier: located_in
review:
summary: >-
Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage
sites within the nucleus.
action: ACCEPT
reason: >-
The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes
BRCA1-A complex activity at DNA double-strand breaks.
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121,
ECO:0000269|PubMed:17643122}.
- reference_id: PMID:17525340
supporting_text: RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response
to ionizing radiation
- term:
id: GO:0005634
label: nucleus
evidence_type: IDA
original_reference_id: PMID:17643121
qualifier: located_in
review:
summary: >-
Supported nuclear localization. ABRAXAS1 acts in the nuclear DNA damage response and localizes to DNA damage
sites within the nucleus.
action: ACCEPT
reason: >-
The UniProt record and the original BRCA1-A studies place ABRAXAS1 in the nucleus, where it recruits/organizes
BRCA1-A complex activity at DNA double-strand breaks.
supported_by:
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Nucleus {ECO:0000269|PubMed:17525340, ECO:0000269|PubMed:17643121,
ECO:0000269|PubMed:17643122}.
- reference_id: PMID:17525340
supporting_text: RAP80 was required for optimal accumulation of BRCA1 on damaged DNA (foci) in response
to ionizing radiation
- term:
id: GO:0006302
label: double-strand break repair
evidence_type: IMP
original_reference_id: PMID:17525340
qualifier: involved_in
review:
summary: >-
Core biological process. ABRAXAS1 is required for efficient DNA double-strand break repair through BRCA1-A
recruitment and ubiquitin-dependent damage-site signaling.
action: ACCEPT
reason: >-
Loss/depletion experiments in the original ABRAXAS1/CCDC98 papers support DNA repair and DNA damage resistance.
The PN-projected broader DNA repair term is already entailed by this annotation.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
supported_by:
- reference_id: PMID:17525340
supporting_text: Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint
control, and DNA repair.
- reference_id: PMID:19261748
supporting_text: a stable complex containing MERIT40 acts early in DNA damage response and regulates
damage-dependent BRCA1 localization
- term:
id: GO:0006302
label: double-strand break repair
evidence_type: IMP
original_reference_id: PMID:17643121
qualifier: involved_in
review:
summary: >-
Core biological process. ABRAXAS1 is required for efficient DNA double-strand break repair through BRCA1-A
recruitment and ubiquitin-dependent damage-site signaling.
action: ACCEPT
reason: >-
Loss/depletion experiments in the original ABRAXAS1/CCDC98 papers support DNA repair and DNA damage resistance.
The PN-projected broader DNA repair term is already entailed by this annotation.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
supported_by:
- reference_id: PMID:17525340
supporting_text: Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint
control, and DNA repair.
- reference_id: PMID:19261748
supporting_text: a stable complex containing MERIT40 acts early in DNA damage response and regulates
damage-dependent BRCA1 localization
- term:
id: GO:0006302
label: double-strand break repair
evidence_type: IMP
original_reference_id: PMID:19261748
qualifier: involved_in
review:
summary: >-
Core biological process. ABRAXAS1 is required for efficient DNA double-strand break repair through BRCA1-A
recruitment and ubiquitin-dependent damage-site signaling.
action: ACCEPT
reason: >-
Loss/depletion experiments in the original ABRAXAS1/CCDC98 papers support DNA repair and DNA damage resistance.
The PN-projected broader DNA repair term is already entailed by this annotation.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
supported_by:
- reference_id: PMID:17525340
supporting_text: Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint
control, and DNA repair.
- reference_id: PMID:19261748
supporting_text: a stable complex containing MERIT40 acts early in DNA damage response and regulates
damage-dependent BRCA1 localization
- term:
id: GO:0010212
label: response to ionizing radiation
evidence_type: IMP
original_reference_id: PMID:17525340
qualifier: involved_in
review:
summary: >-
Supported but non-core phenotype/context annotation. Ionizing radiation is the experimental damage stimulus
used to reveal ABRAXAS1 DNA damage-response function.
action: KEEP_AS_NON_CORE
reason: >-
The IR response annotations should be retained as useful experimental context, but the core process is DNA
double-strand break repair/checkpoint signaling through BRCA1-A.
supported_by:
- reference_id: PMID:18077395
supporting_text: the entire Brca1 A complex to DNA-damage foci
- reference_id: PMID:19261749
supporting_text: required for resistance to ionizing radiation
- term:
id: GO:0010212
label: response to ionizing radiation
evidence_type: IMP
original_reference_id: PMID:17643121
qualifier: involved_in
review:
summary: >-
Supported but non-core phenotype/context annotation. Ionizing radiation is the experimental damage stimulus
used to reveal ABRAXAS1 DNA damage-response function.
action: KEEP_AS_NON_CORE
reason: >-
The IR response annotations should be retained as useful experimental context, but the core process is DNA
double-strand break repair/checkpoint signaling through BRCA1-A.
supported_by:
- reference_id: PMID:18077395
supporting_text: the entire Brca1 A complex to DNA-damage foci
- reference_id: PMID:19261749
supporting_text: required for resistance to ionizing radiation
- term:
id: GO:0010212
label: response to ionizing radiation
evidence_type: IMP
original_reference_id: PMID:19261748
qualifier: involved_in
review:
summary: >-
Supported but non-core phenotype/context annotation. Ionizing radiation is the experimental damage stimulus
used to reveal ABRAXAS1 DNA damage-response function.
action: KEEP_AS_NON_CORE
reason: >-
The IR response annotations should be retained as useful experimental context, but the core process is DNA
double-strand break repair/checkpoint signaling through BRCA1-A.
supported_by:
- reference_id: PMID:18077395
supporting_text: the entire Brca1 A complex to DNA-damage foci
- reference_id: PMID:19261749
supporting_text: required for resistance to ionizing radiation
- term:
id: GO:0031593
label: polyubiquitin modification-dependent protein binding
evidence_type: IDA
original_reference_id: PMID:19261749
qualifier: enables
review:
summary: >-
Core molecular function. ABRAXAS1 is part of a BRCA1-A/RAP80 complex that recognizes ubiquitinated damage-site
chromatin and has polyubiquitin-binding capacity.
action: ACCEPT
reason: >-
The term captures the ubiquitin-recognition side of ABRAXAS1 biology better than generic protein binding.
It should be retained for both direct IDA and IBA evidence.
supported_by:
- reference_id: PMID:19261749
supporting_text: four members of the BRCA1-A complex possess a polyubiquitin chain-binding capability
- reference_id: PMID:20656689
supporting_text: RAP80, in turn, is recruited to DSBs through its tandem ubiquitin-interacting motifs
(UIMs) ( 6 , 14 – 16 ), which specifically recognize K63-Ub chains
- term:
id: GO:0045739
label: positive regulation of DNA repair
evidence_type: IMP
original_reference_id: PMID:17525340
qualifier: involved_in
review:
summary: >-
Core regulatory process. ABRAXAS1 positively supports DNA repair by assembling/stabilizing the RAP80-BRCA1-A
complex at DNA damage sites.
action: ACCEPT
reason: >-
The evidence supports a positive role in DNA repair through BRCA1 localization, complex integrity, and BRCC36-associated
ubiquitin editing rather than direct DNA repair catalysis.
supported_by:
- reference_id: PMID:17525340
supporting_text: Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint
control, and DNA repair.
- reference_id: PMID:19261748
supporting_text: a stable complex containing MERIT40 acts early in DNA damage response and regulates
damage-dependent BRCA1 localization
- reference_id: PMID:20656689
supporting_text: Abraxas and BRCC45 were essential for BRCC36 DUB activity within the RAP80 complex
- term:
id: GO:0045739
label: positive regulation of DNA repair
evidence_type: IMP
original_reference_id: PMID:19261748
qualifier: involved_in
review:
summary: >-
Core regulatory process. ABRAXAS1 positively supports DNA repair by assembling/stabilizing the RAP80-BRCA1-A
complex at DNA damage sites.
action: ACCEPT
reason: >-
The evidence supports a positive role in DNA repair through BRCA1 localization, complex integrity, and BRCC36-associated
ubiquitin editing rather than direct DNA repair catalysis.
supported_by:
- reference_id: PMID:17525340
supporting_text: Both Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint
control, and DNA repair.
- reference_id: PMID:19261748
supporting_text: a stable complex containing MERIT40 acts early in DNA damage response and regulates
damage-dependent BRCA1 localization
- reference_id: PMID:20656689
supporting_text: Abraxas and BRCC45 were essential for BRCC36 DUB activity within the RAP80 complex
- term:
id: GO:0070531
label: BRCA1-A complex
evidence_type: IDA
original_reference_id: PMID:17525340
qualifier: part_of
review:
summary: >-
Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36,
BABAM proteins, and related DDR functions.
action: ACCEPT
reason: >-
Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more
precise than the PN-projected generic ubiquitin-ligase-complex bucket.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
- file:projects/PROTEOSTASIS/mappings/ubiquitin_proteasome_system.yaml
supported_by:
- reference_id: PMID:19261749
supporting_text: Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also
contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0070531
label: BRCA1-A complex
evidence_type: IDA
original_reference_id: PMID:19261746
qualifier: part_of
review:
summary: >-
Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36,
BABAM proteins, and related DDR functions.
action: ACCEPT
reason: >-
Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more
precise than the PN-projected generic ubiquitin-ligase-complex bucket.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
- file:projects/PROTEOSTASIS/mappings/ubiquitin_proteasome_system.yaml
supported_by:
- reference_id: PMID:19261749
supporting_text: Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also
contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0070531
label: BRCA1-A complex
evidence_type: IDA
original_reference_id: PMID:19261748
qualifier: part_of
review:
summary: >-
Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36,
BABAM proteins, and related DDR functions.
action: ACCEPT
reason: >-
Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more
precise than the PN-projected generic ubiquitin-ligase-complex bucket.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
- file:projects/PROTEOSTASIS/mappings/ubiquitin_proteasome_system.yaml
supported_by:
- reference_id: PMID:19261749
supporting_text: Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also
contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
- term:
id: GO:0070531
label: BRCA1-A complex
evidence_type: IDA
original_reference_id: PMID:19261749
qualifier: part_of
review:
summary: >-
Core complex membership. ABRAXAS1 is a BRCA1-A complex subunit that organizes BRCA1, UIMC1/RAP80, BRCC3/BRCC36,
BABAM proteins, and related DDR functions.
action: ACCEPT
reason: >-
Multiple primary studies and Reactome support ABRAXAS1/FAM175A as a BRCA1-A complex component. This is more
precise than the PN-projected generic ubiquitin-ligase-complex bucket.
additional_reference_ids:
- file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
- file:projects/PROTEOSTASIS/mappings/ubiquitin_proteasome_system.yaml
supported_by:
- reference_id: PMID:19261749
supporting_text: Proteomic analysis revealed that NBA1 is a component of the BRCA1 A complex, which also
contains Brca1/Bard1, Abra1, RAP80, BRCC36, and BRE.
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called
BRCA1-A complex at DNA DSBs
references:
- id: GO_REF:0000033
title: Annotation inferences using phylogenetic trees
findings: []
- id: GO_REF:0000044
title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping,
accompanied by conservative changes to GO terms applied by UniProt
findings: []
- id: GO_REF:0000052
title: Gene Ontology annotation based on curation of immunofluorescence data
findings: []
- id: PMID:17525340
title: Abraxas and RAP80 form a BRCA1 protein complex required for the DNA damage response.
findings:
- statement: ABRAXAS1/Abraxas binds BRCA1 BRCT repeats and RAP80, and is required for DNA damage resistance,
G2/M checkpoint control, and DNA repair.
supporting_text: Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and
DNA repair.
reference_section_type: ABSTRACT
- id: PMID:17643121
title: CCDC98 targets BRCA1 to DNA damage sites.
findings: []
- id: PMID:18077395
title: Ubc13/Rnf8 ubiquitin ligases control foci formation of the Rap80/Abraxas/Brca1/Brcc36 complex in
response to DNA damage.
findings: []
- id: PMID:19261746
title: MERIT40 controls BRCA1-Rap80 complex integrity and recruitment to DNA double-strand breaks.
findings: []
- id: PMID:19261748
title: MERIT40 facilitates BRCA1 localization and DNA damage repair.
findings:
- statement: CCDC98/ABRAXAS1 is a central component for assembly of the RAP80-containing BRCA1-A complex at
DNA damage sites.
supporting_text: CCDC98 as the central component that facilitates the assembly of this protein complex
reference_section_type: DISCUSSION
- id: PMID:19261749
title: NBA1, a new player in the Brca1 A complex, is required for DNA damage resistance and checkpoint
control.
findings: []
- id: PMID:19615732
title: Defining the human deubiquitinating enzyme interaction landscape.
findings: []
- id: PMID:20656689
title: Differential regulation of JAMM domain deubiquitinating enzyme activity within the RAP80 complex.
findings:
- statement: ABRAXAS1 is required for BRCC36 DUB activity in the RAP80/BRCA1-A complex context, but is not
itself the catalytic DUB.
supporting_text: Abraxas and BRCC45 were essential for BRCC36 DUB activity within the RAP80 complex
reference_section_type: ABSTRACT
- id: PMID:22369660
title: 'BRCA1 tumor suppressor network: focusing on its tail.'
findings: []
- id: PMID:29656893
title: DNA Repair Network Analysis Reveals Shieldin as a Key Regulator of NHEJ and PARP Inhibitor
Sensitivity.
findings: []
- id: PMID:34591612
title: A protein interaction landscape of breast cancer.
findings: []
- id: PMID:35156780
title: CFTR interactome mapping using the mammalian membrane two-hybrid high-throughput screening system.
findings: []
- id: PMID:36012204
title: Differential CFTR-Interactome Proximity Labeling Procedures Identify Enrichment in Multiple SLC
Transporters.
findings: []
- id: PMID:39009827
title: Proteome-scale characterisation of motif-based interactome rewiring by disease mutations.
full_text_unavailable: true
findings:
- statement: ABRAXAS1 contains a functional nuclear localization signal around Arg361; the
breast-cancer-associated R361Q mutation weakens importin/karyopherin binding approximately
tenfold and increases cytoplasmic localization, providing a molecular basis for impaired
nuclear import of the BRCA1-A complex.
- id: Reactome:R-HSA-5683384
title: UIMC1 and FAM175A bind DNA DSBs
findings: []
- id: Reactome:R-HSA-5683385
title: Formation of BRCA1-A complex at DNA DSBs
findings: []
- id: Reactome:R-HSA-5683735
title: CHEK2 is recruited to DNA DSBs
findings: []
- id: Reactome:R-HSA-5683801
title: CHEK2 phosphorylates BRCA1
findings: []
- id: Reactome:R-HSA-5684052
title: PIAS4 SUMOylates MDC1
findings: []
- id: Reactome:R-HSA-5684071
title: RNF4 ubiquitinates MDC1
findings: []
- id: Reactome:R-HSA-5686685
title: RIF1 and PAX1IP bind TP53BP1 at DNA DSBs
findings: []
- id: Reactome:R-HSA-5691411
title: BRCA1-A complex deubiquitinates K63polyUb-histone H2A
findings: []
- id: Reactome:R-HSA-5693551
title: Phosphorylation of BRCA1-A complex at multiple sites by ATM
findings: []
- id: Reactome:R-HSA-69891
title: Phosphorylation and activation of CHEK2 by ATM
findings: []
- id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
title: ABRAXAS1 UniProtKB record
findings: []
- id: file:human/ABRAXAS1/ABRAXAS1-notes.md
title: ABRAXAS1 manual review notes and failed deep-research provenance
findings: []
- id: file:projects/PROTEOSTASIS/reports/pn_projection/pn_projected_gene_go_summary.tsv
title: Proteostasis PN projected GO summary for ABRAXAS1
findings: []
- id: file:projects/PROTEOSTASIS/mappings/ubiquitin_proteasome_system.yaml
title: Proteostasis ubiquitin proteasome system mapping file
findings: []
- id: file:interpro/panther/PTHR31728/PTHR31728-entries.csv
title: PANTHER PTHR31728 reviewed protein members
findings: []
core_functions:
- molecular_function:
id: GO:0031593
label: polyubiquitin modification-dependent protein binding
description: >-
ABRAXAS1 is a scaffold and ubiquitin-recognition subunit of the nuclear BRCA1-A/RAP80 complex. It helps assemble
BRCA1, UIMC1/RAP80, BRCC3/BRCC36, BABAM proteins, and related partners at ubiquitinated DNA double-strand break
sites, thereby supporting BRCA1 recruitment, BRCC36-dependent K63-ubiquitin signal editing, DNA repair, and
G2/M DNA damage checkpoint signaling.
directly_involved_in:
- id: GO:0006302
label: double-strand break repair
- id: GO:0045739
label: positive regulation of DNA repair
- id: GO:0007095
label: mitotic G2 DNA damage checkpoint signaling
locations:
- id: GO:0005634
label: nucleus
- id: GO:0005654
label: nucleoplasm
in_complex:
id: GO:0070531
label: BRCA1-A complex
supported_by:
- reference_id: PMID:17525340
supporting_text: Abraxas and RAP80 were required for DNA damage resistance, G(2)-M checkpoint control, and
DNA repair.
- reference_id: PMID:19261748
supporting_text: CCDC98 as the central component that facilitates the assembly of this protein complex
- reference_id: PMID:19261749
supporting_text: four members of the BRCA1-A complex possess a polyubiquitin chain-binding capability
- reference_id: PMID:20656689
supporting_text: Abraxas and BRCC45 were essential for BRCC36 DUB activity within the RAP80 complex
- reference_id: Reactome:R-HSA-5683385
supporting_text: Together, BRCA1, BARD1, UIMC1, FAM175A, BRCC36, BRE and BABAM1 form the so-called BRCA1-A
complex at DNA DSBs
- reference_id: file:human/ABRAXAS1/ABRAXAS1-uniprot.txt
supporting_text: Involved in DNA damage response and double-strand break (DSB) repair.
proposed_new_terms: []
suggested_questions:
- question: Should GO curation represent ABRAXAS1 only as part of the BRCA1-A complex, or is there enough
evidence to annotate ABRAXAS1 to a broader ubiquitin ligase complex term despite its scaffold/DUB-support
role?
experts:
- Wang B
- Greenberg RA
- Elledge SJ
- question: Given evidence that ABRAXAS1 truncations shift BRCA1 partitioning toward BRCA1-C and derepress
mutagenic repair (SSA/MMEJ) without impairing HR, should ABRAXAS1 carry a negative-regulation annotation
for low-fidelity double-strand break repair pathways (e.g. single-strand annealing) in addition to its
positive role in DNA repair?
experts:
- Wiesmuller L
- Pylkas K
- question: Is the reported RNA-dependent / direct RNA-binding behavior of ABRAXAS1 (R-DeeP and iCLIP2 in a
single lung-cancer cell line) reproducible and functionally meaningful, or a cell-line-specific
high-throughput artifact, before any RNA-binding annotation is considered?
experts:
- Diederichs S
suggested_experiments:
- hypothesis: The PANTHER-derived spindle and microtubule annotations are ABRAXAS2/paralog-specific and do not
apply to ABRAXAS1.
description: Compare ABRAXAS1 and ABRAXAS2 depletion or rescue in synchronized human cells using spindle
assembly, kinetochore-microtubule attachment, and DNA damage-response readouts in the same experimental
system.
experiment_type: comparative cell biology
- hypothesis: ABRAXAS1 restrains end resection and mutagenic double-strand break repair (single-strand
annealing / microhomology-mediated end joining) by sequestering BRCA1 in the BRCA1-A complex, rather than
simply promoting homologous recombination.
description: Use chromosomally integrated DSB-repair reporters (HR, NHEJ, MMEJ, SSA) in cells expressing
wild-type ABRAXAS1 versus C-terminal SPTF-motif and BRCC36-interaction truncation variants, measuring
pathway-frequency shifts and end-resection markers (RPA, pRPA32, MRE11) to test pathway-choice control.
experiment_type: DSB-repair pathway reporter assay