Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-12-12
pubmed:abstractText
PAC-1 is an inducible, nuclear-specific, dual-specificity mitogen-activated protein (MAP) kinase phosphatase that has been shown recently to be a transcription target of the human tumor-suppressor protein p53 in signaling apoptosis and growth suppression. However, its substrate specificity and regulation of catalytic activity thus far remain elusive. Here, we report in vitro characterization of PAC-1 phosphatase activity with three distinct MAP kinase subfamilies. We show that the recombinant PAC-1 exists in a virtually inactive state when alone in vitro, and dephosphorylates extracellular signal-regulated kinase 2 (ERK2) but not p38alpha or c-Jun NH(2)-terminal kinase 2 (JNK2). ERK2 dephosphorylation by PAC-1 requires association of its amino-terminal domain with ERK2 that results in catalytic activation of the phosphatase. p38alpha also interacts with but does not activate PAC-1, whereas JNK2 does not bind to or cause catalytic activation by PAC-1. Moreover, our structure-based analysis reveals that individual mutation of the conserved Arg294 and Arg295 that likely comprise the phosphothreonine-binding pocket in PAC-1 to either alanine or lysine results in a nearly complete loss of its phosphatase activity even in the presence of ERK2. These results suggest that Arg294 and Arg295 play an important role in PAC-1 catalytic activation induced by ERK2 binding.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
354
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
777-88
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
New insights into the catalytic activation of the MAPK phosphatase PAC-1 induced by its substrate MAPK ERK2 binding.
pubmed:affiliation
Department of Physiology and Biophysics, Mount Sinai School of Medicine, New York University, One Gustave L. Levy Place, New York, NY 10029, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural