Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-2-6
pubmed:abstractText
In the blast crisis phase of chronic myelogenous leukemia (CML), Bcr-Abl(+) myeloblasts fail to undergo terminal maturation. The extracellular signal-regulated kinase (Erk) mitogen-activated protein (MAP) kinase has been shown to mediate terminal differentiation of myeloid cells. Interestingly, Bcr-Abl(+) CML cell lines established from blast crisis were found to have low Erk MAP kinase activity. In this study, we analyzed the role of the Gab2 docking protein in regulation of the Erk MAP kinase in Bcr-Abl(+) K562 human CML cells. Overexpression of Gab2 in K562 cells resulted in transcriptional activation of the c-fos serum response element (SRE) promoter, whereas overexpression of SHP2, Grb2, and CrkL had no effect. Activation of the c-fos SRE transcriptional activity by Gab2 required tyrosine 604, which is a SHP2 docking site on Gab2, and the SHP2 tyrosine phosphatase activity. Elk1, c-Jun, and CHOP trans-reporting assays indicated that overexpression of Gab2 selectively activated the Erk2-Elk1 signaling pathway. To determine cellular consequences of elevating the Gab2 level in K562 cells, stable cell lines for doxycycline-inducible expression of the wild-type Gab2 (Gab2WT) and an SHP2-binding defective Gab2 (Gab2Tyr604Phe) were established. Analysis of these cell lines indicated that induction of Gab2WT expression, but not Gab2Tyr604Phe expression, led to Erk activation, growth arrest, cell spreading, and enlargement; expression of megakaryocyte/platelet lineage-specific integrins alphaIIb/beta3 (CD41/CD61); and upregulation of RNA for megakaryocyte/platelet proteins. All of these changes are characteristics of megakaryocytic differentiation. Together, these results reveal Gab2 as a limiting signaling component for Erk MAP kinase activation and terminal differentiation of K562 CML cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adaptor Proteins, Signal Transducing, http://linkedlifedata.com/resource/pubmed/chemical/DNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/ELK1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Elk1 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Fusion Proteins, bcr-abl, http://linkedlifedata.com/resource/pubmed/chemical/GAB2 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Gab2 protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Mitogen-Activated Protein Kinase 1, http://linkedlifedata.com/resource/pubmed/chemical/Phosphoproteins, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors, http://linkedlifedata.com/resource/pubmed/chemical/ets-Domain Protein Elk-1
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1388-97
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:11830491-Adaptor Proteins, Signal Transducing, pubmed-meshheading:11830491-Animals, pubmed-meshheading:11830491-Cell Differentiation, pubmed-meshheading:11830491-Cell Division, pubmed-meshheading:11830491-DNA-Binding Proteins, pubmed-meshheading:11830491-Enzyme Activation, pubmed-meshheading:11830491-Fusion Proteins, bcr-abl, pubmed-meshheading:11830491-Genes, fos, pubmed-meshheading:11830491-Humans, pubmed-meshheading:11830491-K562 Cells, pubmed-meshheading:11830491-Leukemia, Myeloid, pubmed-meshheading:11830491-Megakaryocytes, pubmed-meshheading:11830491-Mice, pubmed-meshheading:11830491-Mitogen-Activated Protein Kinase 1, pubmed-meshheading:11830491-Phosphoproteins, pubmed-meshheading:11830491-Proto-Oncogene Proteins, pubmed-meshheading:11830491-Signal Transduction, pubmed-meshheading:11830491-Transcription Factors, pubmed-meshheading:11830491-Transcriptional Activation, pubmed-meshheading:11830491-Transfection, pubmed-meshheading:11830491-ets-Domain Protein Elk-1
pubmed:year
2002
pubmed:articleTitle
Regulation of the Erk2-Elk1 signaling pathway and megakaryocytic differentiation of Bcr-Abl(+) K562 leukemic cells by Gab2.
pubmed:affiliation
Molecular Oncology Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't