Premium
Regulation of protein phosphatase 2A‐mediated recruitment of IQGAP1 to β1 integrin by EGF through activation of Ca 2+ /calmodulin‐dependent protein kinase II
Author(s) -
Takahashi Kazuhide,
Suzuki Katsuo
Publication year - 2006
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.20657
Subject(s) - iqgap1 , microbiology and biotechnology , integrin , protein phosphatase 2 , chemistry , phosphorylation , cell adhesion , phosphatase , scaffold protein , signal transduction , biology , biochemistry , cell
Maintenance of β1 integrin‐mediated cell adhesion in quiescent human mammary epithelial (HME) cells requires protein phosphatase (PP) 2A for not only dephosphorylation of β1 integrin but also recruitment of IQGAP1 to Rac‐bound β1 integrin. However, how PP2A‐dependent regulatory machinery of cell adhesion responds to EGF remains to be elucidated. We report here that phosphorylated Ca 2+ /calmodulin‐dependent protein kinase II (CaMKII) at threonine 286 was involved in the β1 integrin complex that consisted of PP2A, Rac, and IQGAP1 in quiescent HME cells. Stimulation of the cells with EGF concomitantly induced an increase in intracellular Ca 2+ , activation of CaMKII, and dissociation of PP2A‐IQGAP1‐CaMKII from β1 integrin‐Rac. Because the activation of CaMKII and dissociation of PP2A‐IQGAP1‐CaMKII were blocked by either Ca 2+ ‐chelator or CaMKII inhibitor, we therefore propose that EGF has the ability to abrogate the PP2A function in the maintenance of β1 integrin‐mediated cell adhesion by dissociation of PP2A‐IQGAP1‐CaMKII from β1 integrin‐Rac through activation of CaMKII. J. Cell. Physiol. © 2006 Wiley‐Liss, Inc.