Exogenous calmodulin increases Ca2+ sensitivity of isometric tension activation and myosin phosphorylation in skinned smooth muscle

P. S. Cassidy, W. Glenn Kerrick, P. E. Hoar, D. A. Malencik

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

We have investigated the effect of exogenous calmodulin on chicken gizzard or rabbit ileum smooth muscle functionally skinned by mechanical grinding or exposure to Triton X-100 detergent. We found that a specific protein inhibitor, modulator binding protein, caused a loss of Ca2+-activated tension which was restored by subsequent treatment with calmodulin. Calmodulin at 5 μM increased 10-fold the speed of development of isometric tension while it had no significant effect on the rate of relaxation or on maximum tension at high Ca2+ concentrations. The Ca2+ sensitivity of steady state tension and LC20 phosphorylation were also increased by 5 μM calmodulin. These results are consistent with a calmodulin-regulated light chain kinase/phosphatase system being responsible for activation of tension in smooth muscle.

Original languageEnglish
Pages (from-to)115-120
Number of pages6
JournalPflügers Archiv European Journal of Physiology
Volume392
Issue number2
DOIs
StatePublished - Dec 1 1981
Externally publishedYes

Fingerprint

Phosphorylation
Calmodulin
Myosins
Smooth Muscle
Muscle
Chemical activation
Avian Gizzard
Octoxynol
Ileum
Phosphoric Monoester Hydrolases
Detergents
Modulators
Chickens
Carrier Proteins
Phosphotransferases
Rabbits
Light
Proteins

Keywords

  • Calmodulin
  • Myosin phosphorylation
  • Skinned smooth muscle

ASJC Scopus subject areas

  • Physiology

Cite this

Exogenous calmodulin increases Ca2+ sensitivity of isometric tension activation and myosin phosphorylation in skinned smooth muscle. / Cassidy, P. S.; Kerrick, W. Glenn; Hoar, P. E.; Malencik, D. A.

In: Pflügers Archiv European Journal of Physiology, Vol. 392, No. 2, 01.12.1981, p. 115-120.

Research output: Contribution to journalArticle

@article{eb289319dfc54b698924d975c8b76990,
title = "Exogenous calmodulin increases Ca2+ sensitivity of isometric tension activation and myosin phosphorylation in skinned smooth muscle",
abstract = "We have investigated the effect of exogenous calmodulin on chicken gizzard or rabbit ileum smooth muscle functionally skinned by mechanical grinding or exposure to Triton X-100 detergent. We found that a specific protein inhibitor, modulator binding protein, caused a loss of Ca2+-activated tension which was restored by subsequent treatment with calmodulin. Calmodulin at 5 μM increased 10-fold the speed of development of isometric tension while it had no significant effect on the rate of relaxation or on maximum tension at high Ca2+ concentrations. The Ca2+ sensitivity of steady state tension and LC20 phosphorylation were also increased by 5 μM calmodulin. These results are consistent with a calmodulin-regulated light chain kinase/phosphatase system being responsible for activation of tension in smooth muscle.",
keywords = "Calmodulin, Myosin phosphorylation, Skinned smooth muscle",
author = "Cassidy, {P. S.} and Kerrick, {W. Glenn} and Hoar, {P. E.} and Malencik, {D. A.}",
year = "1981",
month = "12",
day = "1",
doi = "10.1007/BF00581258",
language = "English",
volume = "392",
pages = "115--120",
journal = "Pflugers Archiv European Journal of Physiology",
issn = "0031-6768",
publisher = "Springer Verlag",
number = "2",

}

TY - JOUR

T1 - Exogenous calmodulin increases Ca2+ sensitivity of isometric tension activation and myosin phosphorylation in skinned smooth muscle

AU - Cassidy, P. S.

AU - Kerrick, W. Glenn

AU - Hoar, P. E.

AU - Malencik, D. A.

PY - 1981/12/1

Y1 - 1981/12/1

N2 - We have investigated the effect of exogenous calmodulin on chicken gizzard or rabbit ileum smooth muscle functionally skinned by mechanical grinding or exposure to Triton X-100 detergent. We found that a specific protein inhibitor, modulator binding protein, caused a loss of Ca2+-activated tension which was restored by subsequent treatment with calmodulin. Calmodulin at 5 μM increased 10-fold the speed of development of isometric tension while it had no significant effect on the rate of relaxation or on maximum tension at high Ca2+ concentrations. The Ca2+ sensitivity of steady state tension and LC20 phosphorylation were also increased by 5 μM calmodulin. These results are consistent with a calmodulin-regulated light chain kinase/phosphatase system being responsible for activation of tension in smooth muscle.

AB - We have investigated the effect of exogenous calmodulin on chicken gizzard or rabbit ileum smooth muscle functionally skinned by mechanical grinding or exposure to Triton X-100 detergent. We found that a specific protein inhibitor, modulator binding protein, caused a loss of Ca2+-activated tension which was restored by subsequent treatment with calmodulin. Calmodulin at 5 μM increased 10-fold the speed of development of isometric tension while it had no significant effect on the rate of relaxation or on maximum tension at high Ca2+ concentrations. The Ca2+ sensitivity of steady state tension and LC20 phosphorylation were also increased by 5 μM calmodulin. These results are consistent with a calmodulin-regulated light chain kinase/phosphatase system being responsible for activation of tension in smooth muscle.

KW - Calmodulin

KW - Myosin phosphorylation

KW - Skinned smooth muscle

UR - http://www.scopus.com/inward/record.url?scp=0019858920&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019858920&partnerID=8YFLogxK

U2 - 10.1007/BF00581258

DO - 10.1007/BF00581258

M3 - Article

C2 - 7322840

AN - SCOPUS:0019858920

VL - 392

SP - 115

EP - 120

JO - Pflugers Archiv European Journal of Physiology

JF - Pflugers Archiv European Journal of Physiology

SN - 0031-6768

IS - 2

ER -