A dynamic approach reveals non-muscle myosin influences the overall smooth muscle cross-bridge cycling rate

Guvenc B., Ustunel C., ÖZTÜRK N., Brozovich F. V.

FEBS LETTERS, vol.584, no.13, pp.2862-2866, 2010 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 584 Issue: 13
  • Publication Date: 2010
  • Doi Number: 10.1016/j.febslet.2010.04.070
  • Journal Name: FEBS LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2862-2866
  • Hacettepe University Affiliated: Yes


Recent evidence suggests that non-muscle myosin IIB (NMIIB) contributes to smooth muscle contraction. This study was designed to determine the effects of NMIIB on the cross-bridge cycling rate. The cross-bridge cycling rate was investigated using sinusoidal analysis. Frequency analysis revealed two asymptotes in the Bode plot of the data; and the intersection of the asymptotes (corner frequency) was higher for the B(+/-) strain (8.73 +/- 1.10 Hz vs 16.56 +/- 1.26 Hz, P < 0.05), consistent with a higher overall cross-bridge cycling rate in heterozygous NMIIB KO (B(+/-)) vs WT mice. These results demonstrate that because of their long duty cycle, NMIIB cross-bridges act as an internal load on smooth muscle myosin to decrease the overall cross-bridge cycling rate and muscle V(max) during force maintenance. (C) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.