RNA recognition motif (RRM) found in BRCA1-associated protein (BRAP2) and similar proteins
This subfamily corresponds to the RRM domain of BRAP2, also termed impedes mitogenic signal propagation (IMP), or ring finger protein 52, or renal carcinoma antigen NY-REN-63, a novel cytoplasmic protein interacting with the two functional nuclear localisation signal (NLS) motifs of BRCA1, a nuclear protein linked to breast cancer. It also binds to the SV40 large T antigen NLS motif and the bipartite NLS motif found in mitosin. BRAP2 may serve as a cytoplasmic retention protein and play a role in the regulation of nuclear protein transport. The family also includes RING finger protein ETP1 and its homologs found in fungi. ETP1, also termed BRAP2 homolog, or ethanol tolerance protein 1, is the yeast homolog of BRCA1-associated protein (BRAP2) found in vertebrates. It may be involved in ethanol and salt-induced transcriptional activation of the NHA1 promoter and heat shock protein genes (HSP12 and HSP26), and participate in ethanol-induced turnover of the low-affinity hexose transporter Hxt3p. Members in this family contain an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by a C3HC4-type ring finger domain and a UBP-type zinc finger.