Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
1999-7-15
pubmed:abstractText
The human band 4.1-related protein-tyrosine phosphatase PTPH1 was introduced into NIH3T3 cells under the control of a tetracycline-repressible promoter. Ectopic expression of wild type PTPH1 dramatically inhibited cell growth, whereas a catalytically impaired mutant showed no effect. To identify the direct target of PTPH1 in the cell, we generated a substrate-trapping mutant, in which an invariant aspartate residue was changed to alanine (D811A in PTPH1). The PTPH1-D811A mutant trapped primarily a 97-kDa tyrosine-phosphorylated protein, which was determined to be VCP (also named p97 or yeast CDC48), from various cell lysates in vitro. However, when expressed in mammalian cells, the D811A mutant was observed to contain high levels of phosphotyrosine and did not trap substrates. Mutation of tyrosine 676 to phenylalanine (Y676F) in the PTPH1-D811A mutant led to a marked reduction in phosphotyrosine content. Furthermore, this double mutant specifically trapped VCP in vivo and recognized the C-terminal tyrosines of VCP, whose phosphorylation is important for cell cycle progression in yeast. Like wild type PTPH1, this double mutant also inhibited cell proliferation. Moreover, induction of wild type PTPH1 resulted in specific dephosphorylation of VCP without changing the overall phosphotyrosine profile of the cells. VCP has been implicated in control of a variety of membrane functions, including membrane fusions, and is a regulator of the cell cycle. Our results suggest that PTPH1 may exert its effects on cell growth through dephosphorylation of VCP, thus implicating tyrosine phosphorylation as an important regulator of VCP function.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17806-12
pubmed:dateRevised
2009-9-3
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Identification of the cell cycle regulator VCP (p97/CDC48) as a substrate of the band 4.1-related protein-tyrosine phosphatase PTPH1.
pubmed:affiliation
Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't