Title: Functions of the Uch37 deubiquitinating enzyme in the proteasome and the INO80 chromatin remodeling complex
Abstract: Deubiquitinating enzymes (DUBs) are proteases that can antagonize ubiquitin‐mediated signalling by disassembling ubiquitin‐protein conjugates. How DUBs are regulated in vivo and how their substrate specificities are achieved are largely unknown. The conserved DUB Uch37 is found on proteasomes in organisms ranging from fission yeast to humans. We recently reported that nuclear Uch37 is also associated with the human INO80 chromatin remodeling complex (hINO80). Whereas deubiquitination by Uch37 is activated by proteasomal binding, Uch37 is inactive within hINO80. Interestingly, it can be activated by transient interactions of hINO80 wih the 26S proteasome. Thus, DUB activities can be modulated both positively and negatively via dynamic interactions with partner proteins. We will present evidence that, for Uch37, this regulation plays a role in control of histone H2B ubiquitination. This work was supported in part by National Institutes of Health grants R01 GM37666 (R.E.C.) and R37 GM41628 (R.C.C.). T.Y. is a fellow of the Leukemia and Lymphoma Society.