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Topors acts as a SUMO‐1 E3 ligase for p53 in vitro and in vivo
Author(s) -
Weger Stefan,
Hammer Eva,
Heilbronn Regine
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.07.088
Subject(s) - sumo protein , ubiquitin ligase , ring finger , ubiquitin , dna ligase , microbiology and biotechnology , hela , in vitro , biology , in vivo , dna damage , ubiquitin protein ligases , endogeny , dna , chemistry , biochemistry , genetics , gene
Human Topors, which was originally identified as cellular binding partner of DNA topoisomerase I and of p53, has recently been shown to function as an ubiquitin E3 ligase for p53 in a manner dependent on its N′‐terminally located RING finger. Here, we demonstrate that Topors also enhances the conjugation of the small ubiquitin‐like modifier 1 (SUMO‐1) to p53 in vivo and in a reconstituted in vitro system. The Topors SUMO‐1 E3 ligase activity does not depend upon its RING finger motif. In HeLa cells, Topors induced p53 sumoylation was accompanied by an increase in endogenous p53 protein levels. Furthermore, Topors enhances the sumoylation of a variety of other, yet unidentified, cellular proteins.