Potential signal mediators for CA2+ sensitization of smooth muscle contraction: Rho-associated kinase, atypical protein kinase C, and arachidonic acid

Protein kinase C (PKC) stimulation of NAD(P)H oxidases (Nox) is an important component of multiple vascular disease processes; however, the relationship between oxidase activation and the regulation of vascular smooth muscle contraction by PKC remains poorly understood. Therefore, we examined the signaling cascade of PKC-elicited Nox activation and the role of superoxide and hydrogen peroxide in mediating PKC-induced vascular contraction. Endothelium-denuded bovine coronary arteries showed a PKC-dependent basal production of lucigenin (5 μM)-detected Nox oxidase-derived superoxide, which was stimulated fourfold by PKC activation with 10 μM phorbol 12,13-dibutyrate (PDBu). PDBu appeared to increase superoxide generation by Nox2 through both p47phox and peroxide-dependent Src activation mechanisms based on the actions of inhibitors, properties of Src phosphorylation, and the loss of responses in aorta from mice deficient in Nox2 and p47phox. The actions of inhibitors of contractile regulating mechanisms, scavengers of superoxide and peroxide, and responses in knockout mouse aortas suggest that a major component of the contraction elicited by PDBu appeared to be mediated through peroxide derived from Nox2 activation stimulating force generation through Rho kinase and calmodulin kinase-II mechanisms. Superoxide generated by PDBu also attenuated relaxation to nitroglycerin. Peroxide-derived from Nox2 activation by PKC appeared to be a major contributor to the thromboxane A2 receptor agonist U46619 (100 nM)-elicited contraction of coronary arteries. Thus a p47phox and Src kinase activation of peroxide production by Nox2 appears to be an important contributor to vascular contractile mechanisms mediated through activation of PKC.

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Probable involvement of epsilon-isoform of protein kinase C in rat bronchial smooth muscle contraction induced by acetylcholine

Journal of Smooth Muscle Research ◽

10.1540/jsmr.44.9 ◽

2008 ◽

Vol 44 (1) ◽

pp. 9-16 ◽

Cited By ~ 3

Author(s):

Hiroyasu Sakai ◽

Maki Yamamoto ◽

Yoshihiko Chiba ◽

Miwa Misawa

Keyword(s):

Smooth Muscle ◽

Protein Kinase C ◽

Protein Kinase ◽

Muscle Contraction ◽

Smooth Muscle Contraction ◽

Bronchial Smooth Muscle ◽

Kinase C

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Possible mechanism to induce protein kinase C-dependent arterial smooth muscle contraction after subarachnoid haemorrhage

Acta Neurochirurgica ◽

10.1007/bf02187196 ◽

1995 ◽

Vol 137 (3-4) ◽

pp. 217-225 ◽

Cited By ~ 15

Author(s):

S. Ohta ◽

J. Nishihara ◽

Y. Oka ◽

H. Todo ◽

Y. Kumon ◽

...

Keyword(s):

Smooth Muscle ◽

Protein Kinase C ◽

Protein Kinase ◽

Subarachnoid Haemorrhage ◽

Muscle Contraction ◽

Smooth Muscle Contraction ◽

Arterial Smooth Muscle ◽

Kinase C

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Myophilin of Echinococcus granulosus: isoforms and phosphorylation by protein kinase C

Parasitology ◽

10.1017/s003118209700108x ◽

1997 ◽

Vol 115 (2) ◽

pp. 205-211 ◽

Cited By ~ 9

Author(s):

R. M. MARTIN ◽

X. F. CSAR ◽

R. B. GASSER ◽

R. FELLEISEN ◽

M. W. LIGHTOWLERS

Keyword(s):

Smooth Muscle ◽

Protein Kinase C ◽

Protein Kinase ◽

Muscle Contraction ◽

Echinococcus Granulosus ◽

Single Gene ◽

Smooth Muscle Contraction ◽

Kinase C ◽

High Amino Acid

Myophilin is a muscle-associated antigen of the taeniid cestode Echinococcus granulosus. This protein shows a high amino acid sequence homology with calponins and calponin-like proteins, which are proposed to be associated with the regulation of smooth muscle contraction. In order to provide supportive evidence for a relationship between these proteins, we characterized myophilin using electrophoretic, biochemical and molecular biological approaches. Two-dimensional protein electrophoretic separation of E. granulosus larval proteins defined 4 isoelectric isoforms of myophilin (α, β, γ and δ), which appeared to be a consequence of post-translational modification of a single gene product. It was also demonstrated biochemically that E. granulosus myophilin undergoes specific phosphorylation in vitro by protein kinase C (PKC). Finally, myophilin homologues were identified in extracts of Taenia hydatigena and T. ovis by immunoblot. A partial cDNA of the closely related species, E. multilocularis, was isolated by cloning procedures and showed 99% homology with the E. granulosus myophilin gene. The similarities of E. granulosus myophilin with calponins in their tissue localization, protein isoform patterns, ability to be phosphorylated in vitro by PKC, and the relatively conserved nature of the protein among related parasites suggest that myophilin may be associated with smooth muscle contraction.

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