TY - JOUR
T1 - Rho-kinase induces association of adducin with the cytoskeleton in platelet activation
AU - Tamaru, Satoshi
AU - Fukuta, Tetsu
AU - Kaibuchi, Kozo
AU - Matsuoka, Yoichiro
AU - Shiku, Hiroshi
AU - Nishikawa, Masakatsu
N1 - Funding Information:
This study was supported in part by grants for research from the Ministry of Education, Science, Technology, Sports and Culture, Japan.
PY - 2005/7/1
Y1 - 2005/7/1
N2 - We examined whether adducin function is regulated through Rho-kinase after agonist stimulation in platelets. A variety of stimuli such as thrombin, STA2 (a stable analog of TXA2), Ca2+ ionophore, phorbol diester, and shear stress induced phosphorylation of α-adducin at Thr445. Preincubation with the Rho-kinase inhibitor Y-27632 in platelets inhibited agonist-induced phosphorylation of α-adducin. STA2 stimulation led to a redistribution of adducin from Triton-insoluble (high speed) fraction (membrane skeleton) to Triton-insoluble (low speed) fraction (cytoskeleton) and detergent-soluble fraction. Phosphoadducin at Thr445 was selectively isolated in the cytoskeletal fraction, whereas phosphoadducin at Ser726 was mainly present in the Triton-soluble fraction. Y-27632 inhibition of STA2-induced α-adducin phosphorylation at Thr445 inhibited incorporation of α-adducin and spectrin into the platelet cytoskeleton, although Y-27632 did not affect phosphorylation of α-adducin at Ser726. These results suggest that Rho-kinase regulates the association of α-adducin and spectrin with the actin cytoskeleton in platelet activation.
AB - We examined whether adducin function is regulated through Rho-kinase after agonist stimulation in platelets. A variety of stimuli such as thrombin, STA2 (a stable analog of TXA2), Ca2+ ionophore, phorbol diester, and shear stress induced phosphorylation of α-adducin at Thr445. Preincubation with the Rho-kinase inhibitor Y-27632 in platelets inhibited agonist-induced phosphorylation of α-adducin. STA2 stimulation led to a redistribution of adducin from Triton-insoluble (high speed) fraction (membrane skeleton) to Triton-insoluble (low speed) fraction (cytoskeleton) and detergent-soluble fraction. Phosphoadducin at Thr445 was selectively isolated in the cytoskeletal fraction, whereas phosphoadducin at Ser726 was mainly present in the Triton-soluble fraction. Y-27632 inhibition of STA2-induced α-adducin phosphorylation at Thr445 inhibited incorporation of α-adducin and spectrin into the platelet cytoskeleton, although Y-27632 did not affect phosphorylation of α-adducin at Ser726. These results suggest that Rho-kinase regulates the association of α-adducin and spectrin with the actin cytoskeleton in platelet activation.
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U2 - 10.1016/j.bbrc.2005.04.127
DO - 10.1016/j.bbrc.2005.04.127
M3 - Article
C2 - 15910744
AN - SCOPUS:19444384157
SN - 0006-291X
VL - 332
SP - 347
EP - 351
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -