TY - JOUR
T1 - PYK2/PDZ-RhoGEF links Ca2+ signaling to RhoA
AU - Ying, Zhekang
AU - Giachini, Fernanda R.C.
AU - Tostes, Rita C.
AU - Webb, R. Clinton
PY - 2009/10
Y1 - 2009/10
N2 - OBJECTIVE-: Ras homolog gene family member A (RhoA)/Rho-kinase-mediated Ca sensitization is a critical component of constrictor responses. The present study investigates how angiotensin II activates RhoA. METHODS AND RESULTS-: Adenoviral vectors were used to manipulate the expression of regulator of G protein signaling (RGS) domain containing Rho-specific guanine exchange factors (RhoGEFs) and proline-rich tyrosine kinase 2 (PYK2), a nonreceptor tyrosine kinase, in primary rat vascular smooth muscle cells. As an evidence of RhoA activation, RhoA translocation and MYPT1 (the regulatory subunit of myosin light chain phosphatase) phosphorylation were analyzed by Western blot. Results showed that overexpression of PDZ-RhoGEF, but not p115-RhoGEF or leukemia-associated RhoGEF (LARG), enhanced RhoA activation by angiotensin II. Knockdown of PDZ-RhoGEF decreased RhoA activation by angiotensin II. PDZ-RhoGEF was phosphorylated and activated by PYK2 in vitro, and knockdown of PDZ-RhoGEF reduced RhoA activation by constitutively active PYK2, indicating that PDZ-RhoGEF links PYK2 to RhoA. Knockdown of PYK2 or PDZ-RhoGEF markedly decreased RhoA activation by A23187, a Ca ionophore, demonstrating that PYK2/PDZ-RhoGEF couples RhoA activation to Ca. CONCLUSIONS-: PYK2 and PDZ-RhoGEF are necessary for angiotensin II-induced RhoA activation and for Ca signaling to RhoA.
AB - OBJECTIVE-: Ras homolog gene family member A (RhoA)/Rho-kinase-mediated Ca sensitization is a critical component of constrictor responses. The present study investigates how angiotensin II activates RhoA. METHODS AND RESULTS-: Adenoviral vectors were used to manipulate the expression of regulator of G protein signaling (RGS) domain containing Rho-specific guanine exchange factors (RhoGEFs) and proline-rich tyrosine kinase 2 (PYK2), a nonreceptor tyrosine kinase, in primary rat vascular smooth muscle cells. As an evidence of RhoA activation, RhoA translocation and MYPT1 (the regulatory subunit of myosin light chain phosphatase) phosphorylation were analyzed by Western blot. Results showed that overexpression of PDZ-RhoGEF, but not p115-RhoGEF or leukemia-associated RhoGEF (LARG), enhanced RhoA activation by angiotensin II. Knockdown of PDZ-RhoGEF decreased RhoA activation by angiotensin II. PDZ-RhoGEF was phosphorylated and activated by PYK2 in vitro, and knockdown of PDZ-RhoGEF reduced RhoA activation by constitutively active PYK2, indicating that PDZ-RhoGEF links PYK2 to RhoA. Knockdown of PYK2 or PDZ-RhoGEF markedly decreased RhoA activation by A23187, a Ca ionophore, demonstrating that PYK2/PDZ-RhoGEF couples RhoA activation to Ca. CONCLUSIONS-: PYK2 and PDZ-RhoGEF are necessary for angiotensin II-induced RhoA activation and for Ca signaling to RhoA.
KW - Angiotensin II
KW - Ca sensitization
KW - PDZ-RhoGEF
KW - PYK2
KW - RhoA
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U2 - 10.1161/ATVBAHA.109.190892
DO - 10.1161/ATVBAHA.109.190892
M3 - Article
C2 - 19759375
AN - SCOPUS:70349582150
SN - 1079-5642
VL - 29
SP - 1657
EP - 1663
JO - Arteriosclerosis, thrombosis, and vascular biology
JF - Arteriosclerosis, thrombosis, and vascular biology
IS - 10
ER -