Effects of exogenously applied calponin on Ca2+-regulated force in skinned smooth muscle of the rabbit mesenteric artery

Takeo Itoh, Satoshi Suzuki, Akito Suzuki, Fumiaki Nakamura, Michiko Naka, Toshio Tanaka

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

To help elucidate the physiological role of calponin (a thin-filament-linked regulatory protein) in smooth muscle contraction, the effects of its exogenous application were investigated on actin-activated MgATPase activity in crude actomyosin from chicken gizzard, and on contraction induced by Ca2+-dependent and -independent means in arterial smooth muscle strips skinned by saponin or β-escin. Calponin concentration dependently inhibited actin-activated MgATPase activity with a proportional increase in its binding to actomyosin and also attenuated Ca2+-induced contractions, in the presence or absence of calmodulin, in skinned arterial strips. Calponin, when phosphorylated by protein kinase C, reduced both its ability to bind to actomyosin and its inhibitory action on actomyosin MgATPase. The phosphorylated calponin also had no effect on the maximum Ca2+-induced contraction in skinned smooth muscle, suggesting that these actions of calponin are not non-specific. Calponin attenuated the Ca2+-independent contraction observed in myosin light chain thio-phosphorylated strips, or on application of trypsin-treated myosin light chain kinase. However, calponin had no effect on maintained rigor contraction. These results suggest that in vascular smooth muscle, calponin may play a physiological role in the inhibition of Ca2+-regulated force, possibly through a direct action on active actin-myosin interactions.

Original languageEnglish
Pages (from-to)301-308
Number of pages8
JournalPflügers Archiv European Journal of Physiology
Volume427
Issue number3-4
DOIs
Publication statusPublished - Jun 1 1994

Fingerprint

Mesenteric Arteries
Smooth Muscle
Muscle
Rabbits
Actomyosin
Actins
Escin
Avian Gizzard
Myosin-Light-Chain Kinase
Myosin Light Chains
calponin
Saponins
Calmodulin
Myosins
Muscle Contraction
Vascular Smooth Muscle
Trypsin
Protein Kinase C
Chickens

All Science Journal Classification (ASJC) codes

  • Physiology
  • Clinical Biochemistry
  • Physiology (medical)

Cite this

Effects of exogenously applied calponin on Ca2+-regulated force in skinned smooth muscle of the rabbit mesenteric artery. / Itoh, Takeo; Suzuki, Satoshi; Suzuki, Akito; Nakamura, Fumiaki; Naka, Michiko; Tanaka, Toshio.

In: Pflügers Archiv European Journal of Physiology, Vol. 427, No. 3-4, 01.06.1994, p. 301-308.

Research output: Contribution to journalArticle

Itoh, Takeo ; Suzuki, Satoshi ; Suzuki, Akito ; Nakamura, Fumiaki ; Naka, Michiko ; Tanaka, Toshio. / Effects of exogenously applied calponin on Ca2+-regulated force in skinned smooth muscle of the rabbit mesenteric artery. In: Pflügers Archiv European Journal of Physiology. 1994 ; Vol. 427, No. 3-4. pp. 301-308.
@article{d4c4dc4896eb41d1b902fa7ce26744ac,
title = "Effects of exogenously applied calponin on Ca2+-regulated force in skinned smooth muscle of the rabbit mesenteric artery",
abstract = "To help elucidate the physiological role of calponin (a thin-filament-linked regulatory protein) in smooth muscle contraction, the effects of its exogenous application were investigated on actin-activated MgATPase activity in crude actomyosin from chicken gizzard, and on contraction induced by Ca2+-dependent and -independent means in arterial smooth muscle strips skinned by saponin or β-escin. Calponin concentration dependently inhibited actin-activated MgATPase activity with a proportional increase in its binding to actomyosin and also attenuated Ca2+-induced contractions, in the presence or absence of calmodulin, in skinned arterial strips. Calponin, when phosphorylated by protein kinase C, reduced both its ability to bind to actomyosin and its inhibitory action on actomyosin MgATPase. The phosphorylated calponin also had no effect on the maximum Ca2+-induced contraction in skinned smooth muscle, suggesting that these actions of calponin are not non-specific. Calponin attenuated the Ca2+-independent contraction observed in myosin light chain thio-phosphorylated strips, or on application of trypsin-treated myosin light chain kinase. However, calponin had no effect on maintained rigor contraction. These results suggest that in vascular smooth muscle, calponin may play a physiological role in the inhibition of Ca2+-regulated force, possibly through a direct action on active actin-myosin interactions.",
author = "Takeo Itoh and Satoshi Suzuki and Akito Suzuki and Fumiaki Nakamura and Michiko Naka and Toshio Tanaka",
year = "1994",
month = "6",
day = "1",
doi = "10.1007/BF00374538",
language = "English",
volume = "427",
pages = "301--308",
journal = "Pflugers Archiv European Journal of Physiology",
issn = "0031-6768",
publisher = "Springer Verlag",
number = "3-4",

}

TY - JOUR

T1 - Effects of exogenously applied calponin on Ca2+-regulated force in skinned smooth muscle of the rabbit mesenteric artery

AU - Itoh, Takeo

AU - Suzuki, Satoshi

AU - Suzuki, Akito

AU - Nakamura, Fumiaki

AU - Naka, Michiko

AU - Tanaka, Toshio

PY - 1994/6/1

Y1 - 1994/6/1

N2 - To help elucidate the physiological role of calponin (a thin-filament-linked regulatory protein) in smooth muscle contraction, the effects of its exogenous application were investigated on actin-activated MgATPase activity in crude actomyosin from chicken gizzard, and on contraction induced by Ca2+-dependent and -independent means in arterial smooth muscle strips skinned by saponin or β-escin. Calponin concentration dependently inhibited actin-activated MgATPase activity with a proportional increase in its binding to actomyosin and also attenuated Ca2+-induced contractions, in the presence or absence of calmodulin, in skinned arterial strips. Calponin, when phosphorylated by protein kinase C, reduced both its ability to bind to actomyosin and its inhibitory action on actomyosin MgATPase. The phosphorylated calponin also had no effect on the maximum Ca2+-induced contraction in skinned smooth muscle, suggesting that these actions of calponin are not non-specific. Calponin attenuated the Ca2+-independent contraction observed in myosin light chain thio-phosphorylated strips, or on application of trypsin-treated myosin light chain kinase. However, calponin had no effect on maintained rigor contraction. These results suggest that in vascular smooth muscle, calponin may play a physiological role in the inhibition of Ca2+-regulated force, possibly through a direct action on active actin-myosin interactions.

AB - To help elucidate the physiological role of calponin (a thin-filament-linked regulatory protein) in smooth muscle contraction, the effects of its exogenous application were investigated on actin-activated MgATPase activity in crude actomyosin from chicken gizzard, and on contraction induced by Ca2+-dependent and -independent means in arterial smooth muscle strips skinned by saponin or β-escin. Calponin concentration dependently inhibited actin-activated MgATPase activity with a proportional increase in its binding to actomyosin and also attenuated Ca2+-induced contractions, in the presence or absence of calmodulin, in skinned arterial strips. Calponin, when phosphorylated by protein kinase C, reduced both its ability to bind to actomyosin and its inhibitory action on actomyosin MgATPase. The phosphorylated calponin also had no effect on the maximum Ca2+-induced contraction in skinned smooth muscle, suggesting that these actions of calponin are not non-specific. Calponin attenuated the Ca2+-independent contraction observed in myosin light chain thio-phosphorylated strips, or on application of trypsin-treated myosin light chain kinase. However, calponin had no effect on maintained rigor contraction. These results suggest that in vascular smooth muscle, calponin may play a physiological role in the inhibition of Ca2+-regulated force, possibly through a direct action on active actin-myosin interactions.

UR - http://www.scopus.com/inward/record.url?scp=0028222198&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028222198&partnerID=8YFLogxK

U2 - 10.1007/BF00374538

DO - 10.1007/BF00374538

M3 - Article

C2 - 8072850

AN - SCOPUS:0028222198

VL - 427

SP - 301

EP - 308

JO - Pflugers Archiv European Journal of Physiology

JF - Pflugers Archiv European Journal of Physiology

SN - 0031-6768

IS - 3-4

ER -