Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

Trybus, K.M. et al.

Conformational states of smooth muscle myosin. Effects of light chain phosphorylation and ionic strength.

Stoichiometric amounts of MgATP disassemble dephosphorylated smooth muscle and nonmuscle myosin filaments to a 10 S monomer. Phosphorylation of the regulatory light chain reassembles the myosin into filaments (Suzuki, H., Onishi, H., Takahashi, K., and Watanabe, S. (1978) J. Biochem. (Tokyo) 84, 1529-1542). The conformation of the dephosphorylated 10 S monomer is highly unusual in that the 1500 A long myosin tail is folded into approximately equal thirds (Onishi, H., and Wakabayashi, T. (1982) J. Biochem. (Tokyo) 92, 871-879; Trybus, K. M., Huiatt, T. W., and Lowey, S. (1982) Proc. Natl. Acad. Sci. U. S. A. 79, 6151-6155). It was recently reported that phosphorylation of the regulatory light chain causes the bent monomer to unfold to the extended conformation characteristic of 6 S myosin in high salt (Craig, R., Smith, R., and Kendrick-Jones, J. (1983) Nature (Lond.) 302, 436-439). Here we show that phosphorylated myosin can exist in a stable 10 S conformation provided that the salt concentration is kept sufficiently low. Only in a narrow range of salt concentration does the monomer conformation depend on the state of phosphorylation. Above 0.3 M KCl, all myosins revert to the extended form; below 0.1 M KCl, all monomeric myosin is folded. As the salt concentration is decreased to 0.05 M KCl, the 10 S monomers form antiparallel folded dimers. Because phosphorylation increases filament formation even when 10 S monomer remains in equilibrium with polymer, assembly could proceed via the association of 10 S monomers or by a transient 6 S intermediate.[1]

References

Conformational states of smooth muscle myosin. Effects of light chain phosphorylation and ionic strength. Trybus, K.M., Lowey, S. J. Biol. Chem. (1984) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.