ubiquitin-like (Ubl) domain found in ubiquitin-like proteins UBL4A and similar proteins
UBL4A, also termed GdX, is a ubiquitously expressed ubiquitin-like (Ubl) protein that forms a complex with partner proteins and participates in the protein processing through endoplasmic reticulum (ER), acting as a chaperone. As a key component of the BCL2-associated athanogene 6 (BAG6) chaperone complex, UBL4A plays a role in mediating DNA damage signaling and cell death. UBL4A also regulates insulin-induced Akt plasma membrane translocation through promotion of Arp2/3-dependent actin branching. Moreover, UBL4A specifically stabilizes the TC45/STAT3 association and promotes dephosphorylation of STAT3 to repress tumorigenesis. UBL4B is testis-specific, and encoded by an X-derived retrogene Ubl4b, which is specifically expressed in post-meiotic germ cells in mammals. As a germ cell-specific cytoplasmic protein, UBL4B is not present in somatic cells. Moreover, UBL4B is present in elongated spermatids, but not in spermatocytes and round spermatids, suggesting its function is restricted to late spermiogenesis. The function of UBL4A may be compensated by either UBL4B or other Ubl proteins in normal conditions. Both UBL4A and UBL4B contain a conserved Ubl domain with a beta-grasp Ubl fold, a common structure involved in protein-protein interactions.
Feature 1: key conserved lysine K27, 1 residue position
Conserved feature residue pattern:[KR]
Evidence:
Comment:K27 (Ub numbering) is a lysine conserved in the Ubl_ubiquitin_like family; it is one of 7 lysines involved in chain linkage in ubiquitin (K6, K11, K27, K29, K33, K48, or K63, Ub numbering); may have other functions, for example for NEDD8 it is involved in the mechanism of protein neddylation
Jiyao W et al.(2023). "The conserved domain database in 2023.",