Actin mediated regulation of muscle contraction

Chalovich, Joseph M.

doi:10.1016/0163-7258(92)90013-p

Cited by 129 publications

(109 citation statements)

References 320 publications

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“…Despite progress on the Ca 2ϩ -induced conformational change in TnC at high resolution (Herzberg et al, 1986;Gagnè et al, 1994), the absence of an atomic strucure for whole troponin has hampered determination of how this change in TnC is transmitted to the remainder of the thin filament. At present, the best supported idea (reviewed in Leavis and Gergely, 1984;Zot and Potter, 1987;Chalovich, 1992) is that TnI interacts with actin in the presence of low Ca 2ϩ concentrations and, because TnI is part of a ternary troponin complex that is bound to tropomyosin, the position of tropomyosin on the actin filament is thereby constrained. Ca 2ϩ binding to TnC releases this constraint by facilitating the interaction between TnI and TnC, which disrupts the TnI-actin binding.…”

Section: Discussionmentioning

confidence: 99%

NH2-terminal Truncation of Skeletal Muscle Troponin T Does Not Alter the Ca2+ Sensitivity of Thin Filament Assembly

Fisher

Wang

Tobacman

1995

Journal of Biological Chemistry

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Section: Discussionmentioning

confidence: 99%

NH2-terminal Truncation of Skeletal Muscle Troponin T Does Not Alter the Ca2+ Sensitivity of Thin Filament Assembly

Fisher

Wang

Tobacman

1995

Journal of Biological Chemistry

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“…Recent studies suggested that CaM-binding thin filament-associated proteins such as caldesmon (CaD) and calponin (CaP) also play an important role in smooth muscle contractility (5). CaD prevents contraction by inhibiting the activity of actomyosin ATPase and disengaging myosin heads from actin (28).…”

mentioning

confidence: 99%

Differences in calmodulin and calmodulin-binding proteins in phasic and tonic smooth muscles

Szymański¹,

Szymańska

Goyal³

2002

American Journal of Physiology-Cell Physiology

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To determine whether densities of calmodulin (CaM) and CaM-binding proteins are related to phasic and tonic behavior of smooth muscles, we quantified these proteins in the opossum esophageal body (EB) and lower esophageal sphincter (LES), which represent phasic and tonic smooth muscles, respectively. Gel electrophoresis, immunoprecipitation, Western blot, and hemagglutinin epitope-tagged CaM (HA-CaM) overlay assay with quantitative scanning densitometry and phosphorylation measurements were used. Total protein content in the two smooth muscles was similar (∼30 mg protein/g frozen tissue). Total tissue concentration of CaM was significantly (25%) higher in EB than in LES ( P < 0.05). HA-CaM-binding proteins were qualitatively similar in LES and EB extracts. Myosin, myristoylated alanine-rich C kinase substrate protein, Ca2+/CaM kinase II, and calponin contents were also similar in the two muscles. However, content and total activity of myosin light chain kinase (MLCK) and content of caldesmon (CaD) were three- to fourfold higher in EB than in LES. Increased CaM and MLCK content may allow for a wide range of contractile force varying from complete relaxation in the basal state to a large-amplitude, high-velocity contraction in EB phasic muscle. Increased content of CaD, which provides a braking mechanism on contraction, may further contribute to the phasic contractile behavior. In contrast, low CaM, MLCK, and CaD content may be responsible for a small range of contractile force seen in tonic muscle of LES.

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“…Studies (11,58) suggest that calmodulin binding thin filament-associated proteins such as caldesmon and calponin plays an important role in smooth muscle contractility. Calponin, an actin-binding protein, inhibits actomyosin ATPase and slows the detachment of myosin from actin (16).…”

mentioning

confidence: 99%

Direct association and translocation of PKC-α with calponin

Patil

Pawar

Bitar

2004

American Journal of Physiology-Gastrointestinal and Liver Physi

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Calponin has been implicated in the regulation of smooth muscle contraction through its interaction with F-actin and inhibition of the actin-activated MgATPase activity of phosphorylated myosin. Calponin has also been shown to interact with PKC. We have studied the interaction of calponin with PKC-α and with the low molecular weight heat-shock protein (HSP)27 in contraction of colonic smooth muscle cells. Particulate fractions from isolated smooth muscle cells were immunoprecipitated with antibodies to calponin and Western blot analyzed with antibodies to HSP27 and to PKC-α. Acetylcholine induced a sustained increase in the immunocomplexing of calponin with HSP27 and of calponin with PKC-α in the particulate fraction, indicating an association of the translocated proteins in the membrane. To examine whether the observed interaction in vivo is due to a direct interaction of calponin with PKC-α, a cDNA of 1.3 kb of human calponin gene was PCR amplified. PCR product encoding 622 nt of calponin cDNA (nt 351–972 corresponding to amino acids 92–229) was expressed as fusion glutathione S-transferase (GST) protein in the vector pGEX -KT. We have studied the direct association of GST-calponin fusion protein with recombinant PKC-α in vitro. Western blot analysis of the fractions collected after elution with reduced glutathione buffer (pH 8.0) show a coelution of GST-calponin with PKC-α, indicating a direct association of GST-calponin with PKC-α. These data suggest that there is a direct association of translocated calponin and PKC-α in the membrane and a role for the complex calponin-PKC-α-HSP27, in contraction of colonic smooth muscle cells.

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Actin mediated regulation of muscle contraction

Cited by 129 publications

References 320 publications

NH2-terminal Truncation of Skeletal Muscle Troponin T Does Not Alter the Ca2+ Sensitivity of Thin Filament Assembly

NH2-terminal Truncation of Skeletal Muscle Troponin T Does Not Alter the Ca2+ Sensitivity of Thin Filament Assembly

Differences in calmodulin and calmodulin-binding proteins in phasic and tonic smooth muscles

Direct association and translocation of PKC-α with calponin

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