RAP80: Ubiquitin-binding protein that specifically recognizes and binds 'Lys-63'-linked ubiquitin. Plays a central role in the BRCA1-A complex by specifically binding 'Lys-63'-linked ubiquitinated histones H2A and H2AX at DNA lesions sites, leading to target the BRCA1-BARD1 heterodimer to sites of DNA damage at double-strand breaks (DSBs). The BRCA1-A complex also possesses deubiquitinase activity that specifically removes 'Lys-63'-linked ubiquitin on histones H2A and H2AX. Also weakly binds monoubiquitin but with much less affinity than 'Lys-63'-linked ubiquitin. May interact with monoubiquitinated histones H2A and H2B; the relevance of such results is however unclear in vivo. Does not bind Lys-48'-linked ubiquitin. May indirectly Act as a transcriptional repressor by inhibiting the interaction of NR6A1 with the corepressor NCOR1. Interacts with TSP57. Component of the BRCA1-A complex, at least composed of the BRCA1, BARD1, UIMC1/RAP80, FAM175A/Abraxas, BRCC3/BRCC36, BRE/BRCC45 and BABAM1/NBA1. In the BRCA1-A complex, interacts directly with FAM175A/Abraxas. Interacts with ESR1, NR6A1 and UBE2I. Expressed in testis, ovary, thymus and heart. Expressed in germ cells of the testis. Belongs to the RAP80 family. 5 isoforms of the human protein are produced by alternative splicing.
Protein type: Transcription, coactivator/corepressor; Nuclear receptor co-regulator
Chromosomal Location of Human Ortholog: 5q35.2
Cellular Component: nucleoplasm; nucleus
Molecular Function: histone binding; protein binding
Biological Process: double-strand break repair; double-strand break repair via nonhomologous end joining; G2/M transition DNA damage checkpoint; negative regulation of transcription, DNA-dependent; positive regulation of DNA repair; response to ionizing radiation; transcription, DNA-dependent
Show more