Abstract
In Swiss 3T3 fibroblasts, the Rac1-specific guanine nucleotide exchange factor Tiam1 is phosphorylated by several different agonists. We show here that PDGF induces threonine phosphorylation of Tiam1 in a time- and dose-dependent manner. Tiam1 phosphorylation was significantly reduced by the selective protein kinase C inhibitor Ro-31-8220 and by KN93, an inhibitor of Ca2+/calmodulin-dependent protein kinase II. The Ca2+ chelator BAPTA/AM totally abrogated Tiam1 phosphorylation, indicating that Ca2+ is essential for this phosphorylation. Moreover, PDGF-stimulated Tiam1 phosphorylation was markedly reduced by 72 +/- 10% in PLC-gamma1 deficient mouse fibroblasts, compared to wild-type cells, indicating that phosphoinositide phospholipase C is involved.
Original language | English |
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Pages (from-to) | 229-33 |
Number of pages | 5 |
Journal | FEBS Letters |
Volume | 429 |
Issue number | 3 |
Publication status | Published - 1998 |
Keywords
- 3T3 Cells
- Animals
- Benzylamines
- Calcium
- Calcium-Calmodulin-Dependent Protein Kinase Type 2
- Calcium-Calmodulin-Dependent Protein Kinases
- Dose-Response Relationship, Drug
- Egtazic Acid
- Guanine Nucleotide Exchange Factors
- Indoles
- Isoenzymes
- Mice
- Phospholipase C gamma
- Phosphorylation
- Platelet-Derived Growth Factor
- Protein Kinase C
- Proteins
- Signal Transduction
- Substrate Specificity
- Sulfonamides
- Threonine
- Type C Phospholipases