Actin Polymerization: Regulation by Divalent Metal Ion and Nucleotide Binding, ATP Hydrolysis and Binding of Myosin
- 1 January 1994
- book chapter
- Published by Springer Nature
- Vol. 358, 71-81
- https://doi.org/10.1007/978-1-4615-2578-3_7
Abstract
Actin filaments are major dynamic components of the cytoskeleton of eukaryotic cells. Assembly of filaments from monomelic actin occurs with expenditure of energy, the tightly bound ATP being irreversibly hydrolyzed during polymerization. This dissipation of energy perturbs the laws of reversible helical polymerization defined by Oosawa and Asakura (1975), and affects the dynamics of actin filaments. We have shown that ATP hydrolysis destabilizes actin-actin interactions in the filament. The destabilization is linked to the liberation of Pi that follows cleavage of the γ-phosphate. Pi release therefore plays the role of a conformational switch. Because ATP hydrolysis is uncoupled from polymerization, the nucleotide content of the filaments changes during the polymerization process, and filaments grow with a stabilizing “cap” of terminal ADP-Pi subunits. The fact that the dynamic properties of F-actin are affected by ATP hydrolysis results in a non-linear dependence of the rate of filament elongation on monomer concentration.Keywords
This publication has 31 references indexed in Scilit:
- Conformational changes in subdomain‐2 of G‐actin upon polymerization into F‐actin and upon binding myosin subfragment‐1FEBS Letters, 1993
- Structural basis for the destabilization of F-actin by phosphate release following ATP hydrolysisJournal of Molecular Biology, 1992
- Inhibition of myosin ATPase by beryllium fluorideBiochemistry, 1992
- Atomic structure of the actin: DNase I complexNature, 1990
- Isolation and characterization of the G-actin–myosin head complexNature, 1989
- Direct identification of the fluoroaluminate and fluoroberyllate species responsible for inhibition of the mitochondrial F1‐ATPaseFEBS Letters, 1989
- Measurement of Pi dissociation from actin filaments following ATP hydrolysis using a linked enzyme assayBiochemical and Biophysical Research Communications, 1987
- Direct evidence for ADP-inorganic phosphate-F-actin as the major intermediate in ATP-actin polymerization. Rate of dissociation of inorganic phosphate from actin filamentsBiochemistry, 1986
- RELATIONSHIPS BETWEEN CHEMICAL AND MECHANICAL EVENTS DURING MUSCULAR CONTRACTIONAnnual Review of Biophysics, 1986
- Structure of the actin–myosin interfaceNature, 1981