UBA domain found in ubiquitin carboxyl-terminal hydrolase UBP25, UBP28, and similar proteins
UBP25, also called deubiquitinating enzyme 25, USP on chromosome 21, ubiquitin thioesterase 25, or ubiquitin-specific-processing protease 25, belongs to the deubiquitinating enzyme (DUB) family that specifically hydrolyzes ubiquitin chains on ubiquitin-conjugated proteins. USP25 has one muscular isoform and two ubiquitous isoforms. The longer muscular isoform can bind to muscle-restricted cytoskeletal and sarcomeric proteins, such as myosin binding protein C1 (MyBPC1), actin alpha-1 (ACTA1) and filamin C (FLNC), and further prevent their degradation. USP25 harbors three potential ubiquitin-binding domains (UBDs), one ubiquitin-associated (UBA) domain and two ubiquitin-interacting motifs (UIMs) in the N-terminal region. Its C-terminal tyrosine-rich region is responsible for the binding of the second SH2 domain of SYK, a non-receptor tyrosine kinase that specifically phosphorylates USP25 and alters its cellular levels. UBP28, also called deubiquitinating enzyme 28, ubiquitin thioesterase 28, or ubiquitin-specific-processing protease 28, is also an ubiquitin-specific protease belonging to the DUB family. UBP28 can form a ternary complex with nucleoplasmic Fbw7alpha, an F-box protein that is part of an SCF-type ubiquitin ligase, and MYC, a transcription factor encoded by MYC proto-oncogene. UBP28 is required for the stability of MYC, and this stabilization is necessary for tumour-cell proliferation. Besides, UBP28 plays a critical role in the regulation of the Chk2-p53-PUMA pathway. It specifically interacts with 53BP1 and is essential to stabilize Chk2 and 53BP1 in response to DNA damage.
Jiyao W et al.(2023). "The conserved domain database in 2023.",