| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520
Correspondence: Address reprint requests to Thomas D. Pollard, MCDB, KBT-548, Yale University, PO Box 208103, New Haven, CT 06520-8103. Fax: 203-432-6161; E-mail: thomas.pollard{at}yale.edu.
Understanding the mechanism of actin polymerization and its regulation by associated proteins requires an assay to monitor polymerization dynamics and filament topology simultaneously. The only assay meeting these criteria is total internal reflection fluorescence microscopy (Amann and Pollard, 2001; Fujiwara et al., 2002). The fluorescence signal is fourfold stronger with actin labeled on Cys-374 with Oregon green rather than rhodamine. To distinguish growth at barbed and pointed ends we used image drift correction and maximum intensity projections to reveal points where single N-ethylmaleimide inactivated myosins attach filaments to the glass coverslip. We estimated association rates at high actin concentrations and dissociation rates near and below the critical actin concentration. At the barbed end, the association rate constant for Mg-ATP-actin is 7.4 µM1 s1 and the dissociation rate constant is 0.89 s1. At the pointed end the association and dissociation rate constants are 0.56 µM1 s1 and 0.19 s1. When vitamin D binding protein sequesters all free monomers, ADP-actin dissociates from barbed ends at 1.4 s1 and from pointed ends at 0.16 s1 regardless of buffer nucleotide.
This article has been cited by other articles:
![]() |
B. J. Nolen and T. D. Pollard Structure and Biochemical Properties of Fission Yeast Arp2/3 Complex Lacking the Arp2 Subunit J. Biol. Chem., September 26, 2008; 283(39): 26490 - 26498. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. M. Neidt, C. T. Skau, and D. R. Kovar The Cytokinesis Formins from the Nematode Worm and Fission Yeast Differentially Mediate Actin Filament Assembly J. Biol. Chem., August 29, 2008; 283(35): 23872 - 23883. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. M. Miller and K. M. Trybus Functional Effects of Nemaline Myopathy Mutations on Human Skeletal {alpha}-Actin J. Biol. Chem., July 11, 2008; 283(28): 19379 - 19388. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Pasic, T. Kotova, and D. A. Schafer Ena/VASP Proteins Capture Actin Filament Barbed Ends J. Biol. Chem., April 11, 2008; 283(15): 9814 - 9819. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Takagi, Y. Yang, I. Fujiwara, D. Jacobs, R. E. Cheney, J. R. Sellers, and M. Kovacs Human Myosin Vc Is a Low Duty Ratio, Nonprocessive Molecular Motor J. Biol. Chem., March 28, 2008; 283(13): 8527 - 8537. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Rizvi, D. S. Courson, V. A. Keller, R. S. Rock, and S. A. Kozmin The dual mode of action of bistramide A entails severing of filamentous actin and covalent protein modification PNAS, March 18, 2008; 105(11): 4088 - 4092. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Roland, J. Berro, A. Michelot, L. Blanchoin, and J.-L. Martiel Stochastic Severing of Actin Filaments by Actin Depolymerizing Factor/Cofilin Controls the Emergence of a Steady Dynamical Regime Biophys. J., March 15, 2008; 94(6): 2082 - 2094. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. P. Brangwynne, G. H. Koenderink, E. Barry, Z. Dogic, F. C. MacKintosh, and D. A. Weitz Bending Dynamics of Fluctuating Biopolymers Probed by Automated High-Resolution Filament Tracking Biophys. J., July 1, 2007; 93(1): 346 - 359. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Berro, A. Michelot, L. Blanchoin, D. R. Kovar, and J.-L. Martiel Attachment Conditions Control Actin Filament Buckling and the Production of Forces Biophys. J., April 1, 2007; 92(7): 2546 - 2558. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Terada, T. Shimozawa, S. Ishiwata, and T. Funatsu Size Distribution of Linear and Helical Polymers in Actin Solution Analyzed by Photon Counting Histogram Biophys. J., March 15, 2007; 92(6): 2162 - 2171. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Shemesh and M. M. Kozlov Actin Polymerization upon Processive Capping by Formin: A Model for Slowing and Acceleration Biophys. J., March 1, 2007; 92(5): 1512 - 1521. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Fischer, E. G. Yarmola, K. L. Weber, K. D. Speicher, D. W. Speicher, M. R. Bubb, and V. M. Fowler Tropomodulin 3 Binds to Actin Monomers J. Biol. Chem., November 24, 2006; 281(47): 36454 - 36465. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. E. Mahaffy and T. D. Pollard Kinetics of the Formation and Dissociation of Actin Filament Branches Mediated by Arp2/3 Complex Biophys. J., November 1, 2006; 91(9): 3519 - 3528. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Wang, Y. Teng, Q. Wang, X. Li, X. Sheng, M. Zheng, J. Samaj, F. Baluska, and J. Lin Imaging of Dynamic Secretory Vesicles in Living Pollen Tubes of Picea meyeri Using Evanescent Wave Microscopy Plant Physiology, August 1, 2006; 141(4): 1591 - 1603. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. S. Harris, I. Rouiller, D. Hanein, and H. N. Higgs Mechanistic Differences in Actin Bundling Activity of Two Mammalian Formins, FRL1 and mDia2 J. Biol. Chem., May 19, 2006; 281(20): 14383 - 14392. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. B. Stukalin and A. B. Kolomeisky ATP Hydrolysis Stimulates Large Length Fluctuations in Single Actin Filaments Biophys. J., April 15, 2006; 90(8): 2673 - 2685. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Haviv, Y. Brill-Karniely, R. Mahaffy, F. Backouche, A. Ben-Shaul, T. D. Pollard, and A. Bernheim-Groswasser Reconstitution of the transition from lamellipodium to filopodium in a membrane-free system PNAS, March 28, 2006; 103(13): 4906 - 4911. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Vavylonis, Q. Yang, and B. O'Shaughnessy Actin polymerization kinetics, cap structure, and fluctuations PNAS, June 14, 2005; 102(24): 8543 - 8548. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |