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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
2000-5-4
pubmed:abstractText
Several guanine nucleotide exchange factors for the Rho family of GTPases that induce activation by exchanging GDP for GTP have been identified. One of these is the tumor invasion gene product Tiam1, which acts on Rac1. In this study, we demonstrate that platelet-derived growth factor (PDGF) and lysophosphatidic acid induce the translocation of Tiam1 to the membrane fraction of NIH 3T3 fibroblasts in a time-dependent manner. Previously, we have shown that Tiam1 is phosphorylated by protein kinase C (PKC) and calcium/calmodulin kinase II (CaMK II) after stimulation with agonists. Here we show, by pretreatment of cells with kinase inhibitors, that CaMK II, but not PKC, is involved in the membrane translocation of Tiam1. Addition of the calcium ionophore ionomycin alone induced the translocation of Tiam1. However, the cell-permeable diacylglycerol oleoylacetylglycerol was without effect and did not enhance the effect of ionomycin. These data further indicated a role for CaMK II and not PKC. Inhibition of phosphoinositide 3-kinase by wortmannin had little effect on the translocation of Tiam1. The role of phosphorylation was further studied by comparing the phosphorylation pattern of Tiam1 in the membranes versus whole cell Tiam1. PDGF-induced phosphorylation of membrane-associated Tiam1 occurred more rapidly than that of the total Tiam1 pool, and CaMK II, but not PKC, played a significant role in this process. Furthermore, by using the p21-binding domain of PAK-3, we show that PDGF, but not lysophosphatidic acid, activates Rac1 in vivo and that this activation involves CaMK II and PKC, but not 3-phosphoinositides. Our results indicate that Tiam1 is translocated to and phosphorylated at membranes after agonist stimulation and that CaMK II, but not PKC, is involved in this process. Also, these kinases are involved in the activation of Rac in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Benzylamines, http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Calmodulin-Dependent..., http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Calmodulin-Dependent..., http://linkedlifedata.com/resource/pubmed/chemical/Diglycerides, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Guanine Nucleotide Exchange Factors, http://linkedlifedata.com/resource/pubmed/chemical/Indoles, http://linkedlifedata.com/resource/pubmed/chemical/KN 93, http://linkedlifedata.com/resource/pubmed/chemical/Lysophospholipids, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Platelet-Derived Growth Factor, http://linkedlifedata.com/resource/pubmed/chemical/Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Ro 31-8220, http://linkedlifedata.com/resource/pubmed/chemical/Sulfonamides, http://linkedlifedata.com/resource/pubmed/chemical/Tiam1 protein, mouse
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9742-8
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:10734127-3T3 Cells, pubmed-meshheading:10734127-Animals, pubmed-meshheading:10734127-Benzylamines, pubmed-meshheading:10734127-Biological Transport, pubmed-meshheading:10734127-Calcium, pubmed-meshheading:10734127-Calcium-Calmodulin-Dependent Protein Kinase Type 2, pubmed-meshheading:10734127-Calcium-Calmodulin-Dependent Protein Kinases, pubmed-meshheading:10734127-Diglycerides, pubmed-meshheading:10734127-Enzyme Inhibitors, pubmed-meshheading:10734127-Guanine Nucleotide Exchange Factors, pubmed-meshheading:10734127-Indoles, pubmed-meshheading:10734127-Lysophospholipids, pubmed-meshheading:10734127-Mice, pubmed-meshheading:10734127-Phosphatidylinositol 3-Kinases, pubmed-meshheading:10734127-Phosphorylation, pubmed-meshheading:10734127-Platelet-Derived Growth Factor, pubmed-meshheading:10734127-Proteins, pubmed-meshheading:10734127-Sulfonamides
pubmed:year
2000
pubmed:articleTitle
Translocation of the Rac1 guanine nucleotide exchange factor Tiam1 induced by platelet-derived growth factor and lysophosphatidic acid.
pubmed:affiliation
Howard Hughes Medical Institute and the Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0295, USA.
pubmed:publicationType
Journal Article