Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2000-3-16
pubmed:abstractText
HePTP is a tyrosine specific protein phosphatase that is strongly expressed in activated T-cells. It was recently demonstrated that in transfected T-cells HePTP impairs TCR-mediated activation of the MAP-kinase family members ERK2 and p38 and it was suggested that both ERK and p38 MAP-kinases are substrates of HePTP. The HePTP gene has been mapped to human chromosome 1q32.1. Abnormalities in this region are frequently found in various hematopoietic malignancies. HePTP is highly expressed in acute myeloid leukemia and its expression in fibroblasts resulted in transformation. To address a possible involvement of HePTP in hematopoietic malignancies we sought to identify HePTP substrate(s) in leukemic cells. Using substrate trapping mutants we have identified the MAP-kinase ERK2 as a specific target of HePTP in the myelogenous leukemia cell line K562. Tyrosine phosphorylated ERK2, but not ERK1, p38, or JNK1, efficiently bound to catalytically inactive HePTP mutants in which the active site cysteine (HePTP-C/S) or the conserved aspartic acid residue (HePTP-D/A) had been exchanged for serine and alanine, respectively. Moreover, the interaction of ERK2 with HePTP trapping mutants was dependent on ERK2 tyrosine phosphorylation, indicating that HePTP is specifically targeted to activated ERK2. Using a deletion mutant of HePTP (HePTP-dLD), in which 14 amino acid residues within the N-terminus are missing, we show that regions outside the catalytic domain are also required for the interaction. Furthermore, overexpression of HePTP in K562 cells and fibroblasts interfered with PMA or growth factor induced MAP-kinase activation and HePTP efficiently dephosphorylated active ERK2 on the tyrosine residue in the activation loop in vitro. Together, these data identify ERK2 as a specific and direct target of HePTP and are consistent with a model in which HePTP negatively regulates ERK2 activity as part of a feedback mechanism. Oncogene (2000) 19, 858 - 869.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Intracellular Signaling Peptides..., http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase 1, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase 3, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinases, http://linkedlifedata.com/resource/pubmed/chemical/PTPN6 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/PTPN7 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Phosphotyrosine, http://linkedlifedata.com/resource/pubmed/chemical/Protein Tyrosine Phosphatase..., http://linkedlifedata.com/resource/pubmed/chemical/Protein Tyrosine Phosphatases, http://linkedlifedata.com/resource/pubmed/chemical/Protein Tyrosine Phosphatases...
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
858-69
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:10702794-Catalytic Domain, pubmed-meshheading:10702794-Humans, pubmed-meshheading:10702794-Immunoblotting, pubmed-meshheading:10702794-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:10702794-Jurkat Cells, pubmed-meshheading:10702794-K562 Cells, pubmed-meshheading:10702794-Mitogen-Activated Protein Kinase 1, pubmed-meshheading:10702794-Mitogen-Activated Protein Kinase 3, pubmed-meshheading:10702794-Mitogen-Activated Protein Kinases, pubmed-meshheading:10702794-Peptides, pubmed-meshheading:10702794-Phosphorylation, pubmed-meshheading:10702794-Phosphotyrosine, pubmed-meshheading:10702794-Protein Binding, pubmed-meshheading:10702794-Protein Tyrosine Phosphatase, Non-Receptor Type 6, pubmed-meshheading:10702794-Protein Tyrosine Phosphatases, pubmed-meshheading:10702794-Protein Tyrosine Phosphatases, Non-Receptor, pubmed-meshheading:10702794-Substrate Specificity, pubmed-meshheading:10702794-Tumor Cells, Cultured
pubmed:year
2000
pubmed:articleTitle
The MAP-kinase ERK2 is a specific substrate of the protein tyrosine phosphatase HePTP.
pubmed:affiliation
DNAX Research Institute, 901 California Avenue, Palo Alto, California, CA 94304, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't