| 2010 |
ABRAXAS2 (KIAA0157/ABRO1) is a cytoplasmic scaffold protein that forms a distinct complex with BRCC36 (separate from the nuclear BRCA1-A complex). KIAA0157 localizes mainly in the cytosol and activates BRCC36 DUB activity in the cytoplasm. Reduction of KIAA0157 expression led to an increase of the BRCA1-A complex in the nucleus, indicating fine balance between the two complexes in vivo. |
Co-immunoprecipitation, subcellular fractionation, siRNA knockdown, functional DUB assays |
The Journal of biological chemistry |
High |
20656690
|
| 2010 |
Within the BRISC complex, KIAA0157 (ABRO1/ABRAXAS2) is the only interaction required for BRCC36 DUB activity; BRISC deficiency enhanced formation of the BRCA1-RAP80 complex in vivo, increasing BRCA1 levels at DNA double-strand breaks. |
In vitro DUB activity assays with purified complexes, Co-IP, siRNA knockdown, laser-induced DSB recruitment assays |
The Journal of biological chemistry |
High |
20656689
|
| 2009 |
ABRO1 binds directly to BRCC36 and the BRCC36-ABRO1 heterodimer constitutes a minimal complex retaining Lys63-specific DUB activity. BRISC selectivity for K63-linked chains is not due to preferential binding to K63 polyubiquitin but is dictated by orientation of the substrate isopeptide bond within the active site. |
Biochemical reconstitution of heterodimer, in vitro DUB assays with defined ubiquitin substrates, binding studies |
The Journal of biological chemistry |
High |
20032457
|
| 2015 |
Crystal structure of the active BRCC36-KIAA0157 (ABRAXAS2) heterodimer and an inactive BRCC36 homodimer was solved. KIAA0157 contacts switch BRCC36 to an active conformation. Higher-order 'super-dimer' assembly (dimer of heterodimers) is required for DUB activity and for interaction with targeting proteins SHMT2 and RAP80, implicating super-dimerization as a regulatory mechanism controlling subcellular localization and biological function. |
X-ray crystallography, in vitro DUB activity assays, mutagenesis, co-immunoprecipitation, size-exclusion chromatography |
Molecular cell |
High |
26344097
|
| 2019 |
Cryo-EM/crystal structures of BRISC and BRCA1-A complexes revealed that ABRO1 (in BRISC) binds SHMT2α (a metabolic enzyme), and this interaction prevents BRCC36 from binding and cleaving ubiquitin chains, establishing a regulatory inhibitory mechanism. In BRCA1-A, the paralog ABRAXAS integrates RAP80 and sequesters BRCA1 away from DSB sites. The two adaptor subunits confer distinct targeting and regulatory functions to BRCC36. |
Cryo-EM structure determination, biochemical binding assays, in vitro DUB inhibition assays |
Molecular cell |
High |
31253574
|
| 2011 |
Both BRCC36-containing complexes (nuclear BRCA1-A with Abraxas; cytoplasmic BRISC with ABRO1) share BRE and NBA1/MERIT40 subunits. NBA1 interacts with BRE through a C-terminal conserved motif of NBA1 and the C-terminal UEV domain of BRE, and this interaction is critical for maintaining the integrity of both complexes and for cellular resistance to ionizing radiation. |
Co-immunoprecipitation, siRNA knockdown, domain-mapping pulldown assays, colony survival after IR |
The Journal of biological chemistry |
Medium |
21282113
|
| 2017 |
ABRO1 protects stalled replication fork stability by inhibiting DNA2 nuclease/WRN helicase-mediated degradation of reversed forks. Depletion of RAD51 prevented DNA2/WRN-dependent fork degradation in Abro1-deficient cells, placing ABRO1 in a fork protection pathway distinct from BRCA2 (which blocks MRE11-dependent degradation). Abro1-null mice display increased chromosome instability and are tumor-prone. |
DNA fiber assay, siRNA/genetic knockdown, mouse knockout, genetic epistasis (RAD51 depletion) |
Genes & development |
High |
28860160
|
| 2020 |
In fork reversal, ABRO1 (along with BRCA2 and FANCD2) protects reversed forks generated by SMARCAL1, ZRANB3, and HLTF from degradation, a pathway distinct from the FBH1-mediated fork remodeling pathway protected by 53BP1/FANCA/FANCC/FANCG/BOD1L/VHL. |
DNA fiber assay, siRNA knockdown, genetic epistasis with multiple fork remodeling factors |
Science advances |
Medium |
33188024
|
| 2022 |
Abro1 (and FANCD2) protect stalled replication forks, and their deficiency leads to accumulation of cytosolic single-stranded DNA (containing ribosomal DNA) that activates cGAS-STING-dependent innate immune signaling in a DNA2-dependent manner. Abro1 and FANCD2 also limit the formation of replication stress-induced P-bodies, which can modulate innate immune activation. |
DNA fiber assay, mouse knockout, immunofluorescence for cytosolic ssDNA, cGAS-STING pathway reporters, P-body quantification |
Nature cell biology |
High |
35817959
|
| 2014 |
ABRO1 stabilizes p53 by facilitating the interaction of p53 with the deubiquitinase USP7. DNA damage induces accumulation of endogenous ABRO1 and its translocation to the nucleus; p53 induction by DNA damage is almost completely attenuated by ABRO1 depletion. |
Co-immunoprecipitation, subcellular fractionation, siRNA knockdown, overexpression, tumor formation assays |
Nature communications |
Medium |
25283148
|
| 2012 |
ABRO1 interacts directly with ATF4, ATF5, and JunD (AP-1 family transcription factors). Under cellular stress, ABRO1 translocates from the cytoplasm to the nucleus and co-localizes with ATF4; this ATF4-ABRO1 interaction is required for the cytoprotective function of ABRO1 following oxidative stress. |
Co-immunoprecipitation, confocal microscopy co-localization, siRNA knockdown, cell viability assays |
Biochimica et biophysica acta |
Medium |
22974638
|
| 2010 |
ABRO1/KIAA0157 interacts with THAP5, a zinc finger transcription factor involved in G2/M control and apoptosis. ABRO1 protein levels increase in myocardial ischemia/reperfusion injury; reducing ABRO1 exacerbated cardiomyocyte death while overexpression provided protection against oxidative stress-induced apoptosis, linked to decreased Lys63-linked ubiquitination of specific substrates. |
Co-immunoprecipitation (ABRO1-THAP5 interaction), in vivo mouse MI/R model, siRNA knockdown, overexpression, cell death assays |
Journal of molecular and cellular cardiology |
Medium |
21195082
|
| 2016 |
ABRO1/BRCC36 (BRISC complex) removes K63-linked ubiquitin chains from tankyrase 1 during G1 phase, countering the action of E3 ligase RNF8 that adds K63-linked chains in late S/G2. This cell cycle-regulated ubiquitination/deubiquitination controls tankyrase 1 stabilization, its association with telomeres, and timely sister telomere resolution. |
Co-immunoprecipitation, ubiquitination assays, siRNA knockdown, telomere FISH, cell cycle synchronization |
The EMBO journal |
High |
27993934
|
| 2019 |
The LNK SH2 domain directly interacts with a phosphorylated tyrosine residue in KIAA0157 (ABRAXAS2). KIAA0157 deficiency in mice leads to expansion of phenotypic and functional HSCs. BRISC (via KIAA0157) attenuates TPO-induced JAK2 K63-ubiquitination; BRISC depletion increases JAK2 K63-ubiquitination, JAK2 activation, MPL receptor surface levels, and membrane-proximal JAK2/MPL association. |
Co-immunoprecipitation, phosphopeptide pull-down, mouse knockout, K63-ubiquitination assays, flow cytometry for HSC phenotyping and MPL surface levels |
Blood |
High |
30755420
|
| 2023 |
ABRO1, as a scaffolding component of the BRISC-BRCC3 complex, is required for NLRP3 deubiquitylation and inflammasome activation in macrophages. Hematopoietic Abro1 deficiency reversed accelerated atherosclerosis and NETosis in Tet2 clonal hematopoiesis mice. |
Mouse knockout (hematopoietic Abro1 KO), bone marrow transplantation, NLRP3 inflammasome activation assays (IL-1β, caspase-1), atherosclerosis quantification |
Circulation |
Medium |
37781816
|
| 2020 |
ABRO1 stabilizes BRCC3 protein by competing with the HECT-type E3 ubiquitin ligase WWP2 for binding to BRCC3, thereby preventing WWP2-mediated ubiquitination and proteasomal degradation of BRCC3. |
Co-immunoprecipitation, ubiquitination assays, siRNA knockdown, overexpression, proteasome inhibitor experiments |
FEBS letters |
Medium |
33107021
|
| 2019 |
FAM175B (ABRAXAS2/ABRO1) interacts with ATF4 as shown by co-localization (confocal microscopy) and co-immunoprecipitation. FAM175B inhibits ubiquitin-dependent ATF4 degradation, elevating ATF4 protein levels, and promotes ATF4-dependent CHOP expression to drive apoptosis in esophageal squamous cell carcinoma cells. |
Co-immunoprecipitation, confocal co-localization, ubiquitination assay, luciferase reporter, siRNA knockdown |
Molecular oncology |
Medium |
30854784
|
| 2023 |
ABRO1 regulates cardiomyocyte proliferation by targeting METTL3-mediated m6A methylation of Psph mRNA. ABRO1 restricts METTL3 activity, reducing PSPH expression; PSPH dephosphorylates CDK2 at Thr14/Tyr15 to activate it. ABRO1 deletion increased cardiomyocyte proliferation and restored heart function after myocardial injury. |
Mouse knockout and overexpression models, m6A methylation assays, CDK2 phosphorylation assays, cardiomyocyte proliferation quantification |
Molecular therapy |
Medium |
36639869
|
| 2025 |
The bacterial T3SS effector NleG6 mediates K27- and K29-linked polyubiquitination at residues K89 and K114 of ABRAXAS2/FAM175B, leading to its degradation through TOLLIP-mediated selective autophagy. ABRAXAS2 degradation triggers subsequent degradation of BRCC3, which in turn prevents TNIP1/ABIN1 degradation and inhibits NF-κB-mediated inflammatory responses. |
Co-immunoprecipitation, ubiquitination site mutagenesis (K89R/K114R), autophagy inhibitor experiments, TOLLIP knockdown, NF-κB reporter assays |
Autophagy |
Medium |
40013521
|
| 2025 |
ABRO1 directly binds YAP and undergoes liquid-liquid phase separation with YAP and PPM1B in a YAP-dependent manner, promoting PPM1B deubiquitination (K63-linked chains at K326) by BRCC36/BRCC3. Smooth muscle cell-specific Abro1-KO mice showed attenuated HFHSD-induced arterial stiffness and TGF-β-Smad signaling. |
GST pull-down, co-immunoprecipitation, immunofluorescence (phase separation), mouse SMC-specific KO, ubiquitination assays, Doppler ultrasound |
Circulation research |
Medium |
39742393
|
| 2026 |
ABRO1 directly interacts with β-catenin and, as part of BRISC, cleaves K63-linked polyubiquitin chains at β-catenin lysine 508, thereby restraining β-catenin nuclear accumulation and transcriptional activation. Cardiomyocyte-specific Abro1 deletion causes spontaneous cardiac hypertrophy and contractile dysfunction reversible by β-catenin inhibitor ICG-001. |
Co-immunoprecipitation, immunoprecipitation-mass spectrometry, ubiquitinome profiling, site-specific mutagenesis (K508R), cardiomyocyte-specific KO/OE mice, CUT&TAG, pharmacological rescue |
Hypertension |
High |
41789465
|
| 2026 |
DPP9 interacts with BRCC36/BRCC3 and ABRO1/ABRAXAS2 (BRISC complex components) as novel binding partners. NanoBRET assays in living cells showed that DPP9 disrupts the binding between BRCC36/BRCC3 and ABRO1/ABRAXAS2, potentially compromising BRISC integrity. |
TurboID proximity labeling, NanoBRET assay in living cells, validation by co-immunoprecipitation |
Cellular and molecular life sciences |
Medium |
41636814
|
| 2020 |
The transcription factor YY1 positively regulates human ABRO1 expression by binding to cis-acting elements located -89 to -59 bp upstream of the ABRO1 transcriptional start site, as demonstrated by ChIP, EMSA, and luciferase reporter assays. |
Reporter gene assays, ChIP, EMSA, YY1 siRNA knockdown and overexpression |
Biochemistry and cell biology |
Medium |
32845162
|