Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1997-6-2
pubmed:abstractText
Protein-tyrosine phosphatases (PTPs) are involved in the regulation of diverse cellular processes and may function as positive effectors as well as negative regulators of intracellular signaling. Recent data demonstrate that malignant transformation of cells is frequently associated with changes in PTP expression or activity. Our analysis of PTP expression in mammary carcinoma cell lines resulted in the molecular cloning of a receptor-like PTP, also known as DEP-1. DEP-1 was found to be expressed at varying levels in mammary carcinoma cell lines and A431 cells. In all tumor cell lines analyzed, DEP-1 was constitutively phosphorylated on tyrosine residues. Phosphorylation of DEP-1 increased significantly after treatment of cells with the PTP inhibitor pervanadate. In A431 cells, tyrosine phosphorylation of DEP-1 was also observed after stimulation with epidermal growth factor, however, only after prolonged exposure of the cells to the ligand, suggesting an indirect mechanism of phosphorylation. In addition, DEP-1 coprecipitated with several tyrosine-phosphorylated proteins from pervanadate-treated cells. In vitro binding experiments using a glutathione S-transferase fusion protein containing the catalytically inactive PTP domain of DEP-1 (Gst-DEP-1-C/S) identify these proteins as potential substrates of DEP-1. In addition, we found a 64-kDa serine/threonine kinase to be constitutively associated with DEP-1 in all tumor cell lines tested. The 64-kDa kinase forms a stable complex with DEP-1 and phosphorylates DEP-1 and DEP-1-interacting proteins in vitro. These data suggest a possible mechanism of DEP-1 regulation in tumor cell lines involving serine/threonine and/or tyrosine phosphorylation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12158-63
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:9115287-Adenosine Triphosphate, pubmed-meshheading:9115287-Amino Acid Sequence, pubmed-meshheading:9115287-Breast Neoplasms, pubmed-meshheading:9115287-Cell Line, pubmed-meshheading:9115287-Cloning, Molecular, pubmed-meshheading:9115287-Conserved Sequence, pubmed-meshheading:9115287-Female, pubmed-meshheading:9115287-Humans, pubmed-meshheading:9115287-Kinetics, pubmed-meshheading:9115287-Molecular Weight, pubmed-meshheading:9115287-Phosphoproteins, pubmed-meshheading:9115287-Phosphorylation, pubmed-meshheading:9115287-Protein Tyrosine Phosphatases, pubmed-meshheading:9115287-Protein-Serine-Threonine Kinases, pubmed-meshheading:9115287-Receptor-Like Protein Tyrosine Phosphatases, Class 3, pubmed-meshheading:9115287-Recombinant Proteins, pubmed-meshheading:9115287-Transfection, pubmed-meshheading:9115287-Tumor Cells, Cultured, pubmed-meshheading:9115287-Vanadates
pubmed:year
1997
pubmed:articleTitle
The receptor-like protein-tyrosine phosphatase DEP-1 is constitutively associated with a 64-kDa protein serine/threonine kinase.
pubmed:affiliation
SUGEN, Inc., Redwood City, California 94063, USA.
pubmed:publicationType
Journal Article