TRIM44 interacts with and stabilizes terf, a TRIM ubiquitin E3 ligase

• Published in: Biochemical and biophysical research communications 2009-05, Vol.383 (2), p.263-268
• Main Authors: Urano, Tomohiko, Usui, Takahiko, Takeda, Shizu, Ikeda, Kazuhiro, Okada, Atsushi, Ishida, Yoshiko, Iwayanagi, Takao, Otomo, Jun, Ouchi, Yasuyoshi, Inoue, Satoshi
• Format: Article
• Language: English
• Subjects: Animals; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cell Line; E3 ubiquitin ligase; Humans; Male; Mice; RING finger; Terf; Testis - metabolism; TRIM44; Two-Hybrid System Techniques; Ubiquitin-Protein Ligases - genetics; Ubiquitin-Protein Ligases - metabolism; Ubiquitination
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2009.04.010

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.