Ca2+ sensitivity of smooth muscle and nonmuscle myosin II: modulated by G proteins, kinases, and myosin phosphatase.
It is suggested that the RhoA/ROK pathway is constitutively active in a number of organs under physiological conditions; its aberrations play major roles in several disease states, particularly impacting on Ca2+ sensitization of smooth muscle in hypertension and possibly asthma and on cancer neoangiogenesis and cancer progression.
Signal transduction and regulation in smooth muscle
Abnormalities of these regulatory mechanisms and isoform variations may contribute to diseases of smooth muscle, and the G-protein-coupled inhibition of protein phosphatase is also likely to be impor-tant in regulating non-muscle cell functions mediated by cytoplasmic myosin II.
Signal transduction by G‐proteins, Rho‐kinase and protein phosphatase to smooth muscle and non‐muscle myosin II
Ca2+ sensitization by the Rho/Rho‐kinase pathway contributes to the tonic phase of agonist‐induced contraction in smooth muscle, and abnormally increased activation of myosin II by this mechanism is thought to play a role in diseases such as high blood pressure and cancer cell metastasis.
Smooth Muscle Differentiation Marker Gene Expression Is Regulated by RhoA-mediated Actin Polymerization*
- C. Mack, A. Somlyo, M. Hautmann, A. Somlyo, G. Owens
- BiologyJournal of Biological Chemistry
- 5 January 2001
The results of these studies indicate that in SMC, RhoA-dependent regulation of the actin cytoskeleton selectively regulates SMC differentiation marker gene expression by modulating SRF-dependent transcription and suggest that RHoA signaling may serve as a convergence point for the multiple signaling pathways that regulate SMC differentiate.
SARCOPLASMIC RETICULUM AND EXCITATION-CONTRACTION COUPLING IN MAMMALIAN SMOOTH MUSCLES
The presence of both thick and thin myofilaments and of rough SR in smooth muscles supports the dual, contractile and morphogenetic, function of smooth muscle.
Calcium release and ionic changes in the sarcoplasmic reticulum of tetanized muscle: an electron-probe study
- A. Somlyo, H. Gonzalez-serratos, H. Shuman, G. McClellan, A. Somlyo
- BiologyJournal of Cell Biology
- 1 September 1981
The unchanged distribution of a permeant anion, chloride, argues against the existence of a large and sustained transSR potential during tetanus, if the chloride permeability of the in situ SR is as high as suggested by measurements on fractionated SR.
Arachidonic acid inhibits myosin light chain phosphatase and sensitizes smooth muscle to calcium.
- M. Gong, A. Fuglsang, A. Somlyo
- Biology, ChemistryJournal of Biological Chemistry
- 25 October 1992
G protein-mediated inhibition of myosin light-chain phosphatase in vascular smooth muscle.
- Toshio Kitazawa, M. Masuo, A. Somlyo
- Biology, ChemistryProceedings of the National Academy of Sciences…
- 15 October 1991
Inhibition of protein phosphatase(s) by G protein may have important regulatory functions and is suggested to account for maximal G protein-mediated Ca2+ sensitization of MLC phosphorylation.
The effects of the Rho‐kinase inhibitor Y‐27632 on arachidonic acid‐, GTPγS‐, and phorbol ester‐induced Ca2+‐sensitization of smooth muscle
- Xiaohong Fu, M. Gong, Taiping Jia, A. Somlyo, A. Somlyo
- BiologyFEBS Letters
- 27 November 1998
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