Critical regions for deubiquitinating activity of DUB-2 expressed in T-lymphocytes

Ubiquitin- and proteasome-mediated protein degradation is involved in many intracellular processes, including cell cycle regulation, transcriptional a ctivation, and signal transduction in all eukaryotes, Novel subfamily membe rs of the ubp superfamily, DUB-1 and DUB-2, are known to be immediate-early genes and are specifically expressed in B-lymphocytes end T-lymphocytes, r espectively. With the site-directed mutagenesis in four conserved amino aci ds (Cys60, Asp133, His298, and His307) and a series of deletion in the carb oxy-terminal region, we demonstrate that these conserved amino acids are cr itical, but not the C-terminus, for the deubiquitinating activity of DUB-P, (C) 2001 Wiley-Liss, Inc.