Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein tyrosine phosphorylation and dephosphorylation have been implicated in the growth and functional responses of hematopoietic cells. Recent studies have identified a novel protein tyrosine phosphatase, termed hematopoietic cell phosphatase (HCP) or PTP1C, that is predominantly expressed in hematopoietic cells. HCP encodes a cytoplasmic phosphatase that contains two src homology 2 (SH2) domains. Since SH2 domains have been shown to target the association of signal-transducing molecules with activated growth factor receptors containing intrinsic protein kinase activity, we assessed the association of HCP with two hematopoietic growth factor receptors, c-Kit and c-Fms. The results demonstrate that HCP transiently associates with ligand-activated c-Kit but not c-Fms and that this association occurs through the SH2 domains. In both colony-stimulating factor 1- and stem cell factor-stimulated cells, there is a marginal increase in tyrosine phosphorylation of HCP. Lastly, HCP can dephosphorylate autophosphorylated c-Kit and c-Fms in in vitro reactions. The potential role of HCP in stem cell factor signal transduction is discussed.
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PMID:Association of hematopoietic cell phosphatase with c-Kit after stimulation with c-Kit ligand. 768 96

Activating mutations in the Kit receptor tyrosine kinase have been identified in both rodent and human mast cell leukemia. One activating Kit mutation substitutes a valine for aspartic acid at codon 816 (D816V) and is frequently observed in human mastocytosis. Mutation at the equivalent position in the murine c-kit gene, involving a substitution of tyrosine for aspartic acid (D814Y), has been described in the mouse mastocytoma cell line P815. We have investigated the mechanism of oncogenic activation by this mutation. Expression of this mutant Kit receptor tyrosine kinase in a mast cell line led to the selective tyrosine phosphorylation of a 130-kDa protein and the degradation, through the ubiquitin-dependent proteolytic pathway, of a 65-kDa phosphoprotein. The 65-kDa protein was identified as the src homology domain 2 (SH2)-containing protein tyrosine phosphatase SHP-1, a negative regulator of signaling by Kit and other hematopoietic receptors, and the protein product of the murine motheaten locus. This mutation also altered the sites of receptor autophosphorylation and peptide substrate selectivity. Thus, this mutation activates the oncogenic potential of Kit by a novel mechanism involving an alteration in Kit substrate recognition and the degradation of SHP-1, an attenuator of the Kit signaling pathway.
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PMID:Oncogenic mutation in the Kit receptor tyrosine kinase alters substrate specificity and induces degradation of the protein tyrosine phosphatase SHP-1. 896 11

The SH2 domain-containing tyrosine phosphatase PTPN6 (SHP-1, PTP1C, HCP) is a 68 kDa cytoplasmic protein primarily expressed in hematopoietic cell development, proliferation and receptor-mediated mitogenic signaling pathways. By means of direct dephosphorylation, it down-regulates a broad spectrum of growth-promoting receptors, including the Kit tyrosine kinase, activated to elicit a prominent cascade of intracellular events by stem cell factor binding. The pivotal contribution of PTPN6 in modulating myeloid cell signaling has been revealed by the finding that shp-1 mutation is responsible for the overexpansion and inappropriate activation of myelomonocytic populations in motheaten (me/me) and motheaten viable (me(v)/me(v)) mice. Association of PTPN6 with c-Kit and negative modulation of the myeloid leukocyte signal transduction pathways prompted us to examine the expression of the protein tyrosine phosphatase PTPN6 gene in CD34(+)/CD117(+) blasts from acute myeloid leukemia patients. We identified and cloned cDNAs representing novel PTPN6 mRNA species, derived from aberrant splicing within the N-SH2 domain leading to retention of intron 3. Sequence analysis of cDNA clones revealed multiple A-->G editing conversions. The editing of PTPN6 mRNA mainly occurred as an A-->G conversion of A(7866), which represents the putative branch site in IVS3 of PTPN6 mRNA. Evidence that editing of A(7866) abrogates splicing has been obtained in vitro by using an edited clone and its backward clone generated by site-directed mutagenesis. The level of the aberrant intron-retaining splice variant, evaluated by semi-quantitative RT-PCR, was lower in CD117(+)-AML bone marrow mononuclear cells at remission than at diagnosis, suggesting the involvement of post-transcriptional PTPN6 processing in leukemogenesis.
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PMID:RNA hyperediting and alternative splicing of hematopoietic cell phosphatase (PTPN6) gene in acute myeloid leukemia. 1100 33

The aim of study is to investigate the expression of hematopoietic cell phosphatase (SHP-1) gene and c-kit pro-oncogene in acute leukemia (AL) and its impact on prognosis in AL. Semi-quantity reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the expression of SHP-1 mRNA and c-kit mRNA in 60 AL patients and 33 normal controls (NC). The results showed that the positive rates of SHP-1 expression from high to low level were found orderly in complete remission group, newly diagnosed group and relapsed group, there was significance difference between each group and NC group (P < 0.05). The positive rates of c-kit expression were opposite order in each groups as compared with SHP-1. there was also significance difference between each group and NC group (P < 0.05). The positive rate of SHP-1 and c-kit expressions in AML was higher than that in ALL (P < 0.05), there was negative correlation between expressions of SHP-1 and c-kit (r = -0.502, P < 0.05); The difference between the complete remission rate in SHP-1 positive and in SHP-1 negative patients from 30 newly diagnosed AML patients was significant (P < 0.05), the same result was found between c-kit(+) complete remission and c-kit(-) complete remission. It is concluded that SHP-1 gene is a potentially anti-oncogene and inhibits the growing of tumor by negatively modulating c-kit gene. Simultaneous detection of SHP-1 and c-kit gene may act as a factor for predicting prognosis in AL.
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PMID:[Expression and clinical value of SHP-1 and c-kit in acute leukemia]. 1709 78