SUMO-1 represses apoptosis signal-regulating kinase 1 activation through physical interaction and not through covalent modification.

ABSTRACT: This study examined whether small ubiquitin-related modifier-1 (SUMO-1) regulates apoptosis signal-regulating kinase 1 (ASK 1). ASK 1 interacted with SUMO-1 in vitro as well as in BOSC 23 cells. Endogenous ASK 1-SUMO-1 interaction was disrupted following H(2)O(2) signal. SUMO-1 overexpression suppressed the self-oligomerization, kinase activity and apoptotic potential of ASK 1, whereas SUMO-1 depletion potentiated such activities. SUMO-1(Delta C 6), a sumoylation-incompetent mutant lacking carboxy-terminal six amino acids, suppressed AS 1 activation, implying that the suppressive effect of SUMO-1 on ASK 1 is independent of sumoylation. ASK 1(3M), an ASK 1 mutant in which all three lysines in the psiKXE motif were substituted with alanines, still retained the kinase activity and activated t

SUBMITTER: Lee YS 

PROVIDER: S-EPMC1369187 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature