Load-dependent mechanism of nonmuscle myosin 2

M. Kovács, Kavitha Thirumurugan, Peter J. Knight, James R. Sellers

Research output: Contribution to journalArticle

127 Citations (Scopus)

Abstract

Loads on molecular motors regulate and coordinate their function. In a study that directly measures properties of internally strained myosin 2 heads bound to actin, we find that human nonmuscle myosins 2A and 2B show marked load-dependent changes in kinetics of ADP release but not in nucleotide binding. We show that the ADP release rate constant is increased 4-fold by the assisting load on one head and decreased 5-fold (for 2A) or 12-fold (for 2B) by the resisting load on the other. Thus these myosins, especially 2B, have marked mechanosensitivity of product release. By regulating the actin attachment of myosin heads, this provides a basis for energy-efficient tension maintenance without obstructing cellular contractility driven by other motors such as smooth muscle myosin. Whereas forward load accelerates the cycle of interaction with actin, resistive load increases duty ratio to favor tension maintenance by two-headed attachment.

Original languageEnglish
Pages (from-to)9994-9999
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume104
Issue number24
DOIs
Publication statusPublished - Jun 12 2007

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Myosins
Actins
Adenosine Diphosphate
Head
Maintenance
Smooth Muscle Myosins
Nucleotides

Keywords

  • Actomyosin
  • Cytoskeleton
  • Kinetics
  • Load dependence
  • Myosin

ASJC Scopus subject areas

  • Genetics
  • General

Cite this

Load-dependent mechanism of nonmuscle myosin 2. / Kovács, M.; Thirumurugan, Kavitha; Knight, Peter J.; Sellers, James R.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 104, No. 24, 12.06.2007, p. 9994-9999.

Research output: Contribution to journalArticle

Kovács, M. ; Thirumurugan, Kavitha ; Knight, Peter J. ; Sellers, James R. / Load-dependent mechanism of nonmuscle myosin 2. In: Proceedings of the National Academy of Sciences of the United States of America. 2007 ; Vol. 104, No. 24. pp. 9994-9999.
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