TRIM44 interacts with and stabilizes terf, a TRIM ubiquitin E3 ligase.
Terf/TRIM17 is a member of the TRIM family of proteins, which is characterized by the RING finger, B-box, and coiled-coil domains. In the present study, we found that terf interacts with TRIM44. Terf underwent ubiquitination in vitro in the presence of the E2 enzyme UbcH6; this suggests that terf exhibits E3 ubiquitin ligase activity. It was also found that terf was conjugated with polyubiquitin chains and stabilized by the proteasome inhibitor in mammalian cells; this suggested that terf rendered itself susceptible to proteasomal degradation through polyubiquitination. We also found that TRIM44 inhibited ubiquitination of terf, and thus stabilized the protein. The N-terminal region of TRIM44 contains a zinc-finger domain found in ubiquitin hydrolases (ZF UBP) and ubiquitin specific proteases (USPs). Thus, we proposed that TRIM44 may function as a new class of the "USP-like-TRIM" which regulates the activity of associated TRIM proteins.
Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Tomohiko
T
Urano
Takahiko
T
Usui
Shizu
S
Takeda
Kazuhiro
K
Ikeda
Atsushi
A
Okada
Yoshiko
Y
Ishida
Takao
T
Iwayanagi
Jun
J
Otomo
Yasuyoshi
Y
Ouchi
Satoshi
S
Inoue
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D013737:Testis / Q000378:metabolism*; D000070584:Tripartite Motif Proteins; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C540677:TRIM44 protein, human; D000070584:Tripartite Motif Proteins; C115437:TRIM17 protein, human; D044767:Ubiquitin-Protein Ligases