Linked Life Data

12898523

Source:http://linkedlifedata.com/resource/pubmed/id/12898523

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2003-8-4
pubmed:abstractText
We recently characterized the interaction between poly(ADP-ribose) polymerase-1 (PARP-1) and the product of the tumor suppressor gene p53. We investigated which domains of human PARP-1 and of human wild-type (wt) p53 were involved in this protein-protein interaction. We generated baculoviral constructs encoding full length or distinct functional domains of both proteins. Full length PARP-1 was simultaneously coexpressed in insect cells with full length wt p53 protein or its distinct truncated fragments and vice versa. Reciprocal immunoprecipitation of Sf9 cell lysates revealed that the central and carboxy-terminal fragments of p53 were sufficient to confer binding to PARP-1, whereas the amino-terminal part harboring the transactivation functional domain was dispensable. On the other hand, the amino-terminal and central fragments of PARP-1 were necessary for complex formation with p53 protein. As the most important features of p53 protein are regulated by phosphorylation, we addressed the question of whether its phosphorylation is essential for binding between the two proteins. Baculovirally expressed wt p53 was post-translationally modified. At least six distinct p53 isomeres were resolved by immunoblotting following two-dimensional separation of baculovirally expressed wt p53 protein. Using specific phospho-serine antibodies, we identified phosphorylation of baculovirally expressed p53 protein at five distinct sites. To define the role of p53 phosphorylation, pull-down assays using untreated and dephosphorylated p53 protein were performed. Dephosphorylated p53 failed to bind PARP-1 indicating that complex formation between both proteins is regulated by phosphorylation of p53. The marked phosphorylation of p53 at Ser392 observed in unstressed cells suggests that the phosphorylated carboxy-terminal part of p53 undergoes complex formation with PARP-1 resulting in masking of the NES and thereby preventing its export. The functional significance of the interaction between both proteins was investigated at two different conditions: inactivation of PARP-1 and overexpression of PARP-1. Our results unequivocally show that the presence of PARP-1 regulates the basal expression of wt p53 in unstressed cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0730-2312
pubmed:author
pubmed:copyrightInfo
Copyright 2003 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
89
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1260-84
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Phosphorylation regulates the interaction and complex formation between wt p53 protein and PARP-1.
pubmed:affiliation
Cell Cycle Regulation Unit, Institute of Cancer Research, University of Vienna, Vienna, Austria.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't