Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P62988 (Ubiquitin)
 4,326 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

BRCC36 is a member of the JAMM/MPN(+) family of zinc metalloproteases that specifically cleaves Lys 63-linked polyubiquitin chains in vitro. We and others showed previously that BRCC36 is a component of the BRCA1-A complex, which consists of RAP80, CCDC98/ABRAXAS, BRCC45/BRE, MERIT40/NBA1, BRCC36, and BRCA1. This complex participates in the regulation of BRCA1 localization in response to DNA damage. Here we provide evidence indicating that BRCC36 regulates the abundance of Lys(63)-linked ubiquitin chains at chromatin and that one of its substrates is diubiquitinated histone H2A. Moreover, besides interacting with CCDC98 within the BRCA1-A complex, BRCC36 also associates with another protein KIAA0157, which shares significant sequence homology with CCDC98. Interestingly, although CCDC98 functions as an adaptor of BRCC36 and regulates BRCC36 activity in the nucleus, KIAA0157 mainly localizes in cytosol and activates BRCC36 in the cytoplasm. Moreover, these two complexes appear to exist in fine balance in vivo because reduction of KIAA0157 expression led to an increase of the BRCA1-A complex in the nucleus. Together, these results suggest that scaffold proteins not only participate in the regulation of BRCC36 activity but also determine its subcellular localization and cellular functions.
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PMID:The Lys63-specific deubiquitinating enzyme BRCC36 is regulated by two scaffold proteins localizing in different subcellular compartments. 2065 90

Abro1 (also known as KIAA0157) is a scaffold protein that recruits polypeptides to assemble the BRISC (BRCC36-containing isopeptidase complex) deubiquitinating (DUB) enzyme. The four subunits of BRISC enzyme include Abro1, NBA1, BRE, and BRCC36 proteins. The DUB activity of the BRISC enzyme is exclusively directed against Lys63-linked polyubiquitin that does not have a proteolytic role but regulates protein function. In this report, we identified Abro1 as a specific interactor of THAP5, a zinc finger transcription factor that is involved in G2/M control and apoptosis. Abro1 was predominantly expressed in the heart and its protein level was regulated following experimentally induced myocardial ischemia/reperfusion (MI/R) injury. Furthermore, in patients with coronary artery disease (CAD), there was a dramatic increase in Abro1 protein level in the myocardial infarction (MI) area. Increase in Abro1 leads to a significant reduction in Lys63-linked ubiquitination of specific protein targets. Reducing the Abro1 protein level exacerbated cellular damage and cell death of cardiomyocytes due to MI/R injury. Additionally, overexpression of Abro1 in a heterologous system provided significant protection against oxidative stress-induced apoptosis. In conclusion, our results demonstrate that Abro1 protein level substantially increases in myocardial injury and coronary artery disease and this up-regulation is part of a novel cardioprotective mechanism. In addition, our data suggest a potential new link between Lys63-specific ubiquitination, its modulation by the BRISC DUB enzyme, and the development and progression of heart disease.
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PMID:Regulation of Abro1/KIAA0157 during myocardial infarction and cell death reveals a novel cardioprotective mechanism for Lys63-specific deubiquitination. 2119 82