QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 17, Issue 5, 2190-2199, May 2006

This Article Full Text Full Text (PDF) Supplemental Material All Versions of this Article: E05-11-1016v1 17/5/2190    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mohri, K. Articles by Ono, S. Search for Related Content PubMed PubMed Citation Articles by Mohri, K. Articles by Ono, S.

Enhancement of Actin-depolymerizing Factor/Cofilin-dependent Actin Disassembly by Actin-interacting Protein 1 Is Required for Organized Actin Filament Assembly in the Caenorhabditis elegans Body Wall Muscle

Department of Pathology, Emory University, Atlanta, GA 30322

Submitted November 4, 2005; Revised February 6, 2006; Accepted February 24, 2006
Monitoring Editor: Thomas Pollard

Regulated disassembly of actin filaments is involved in several cellular processes that require dynamic rearrangement of the actin cytoskeleton. Actin-interacting protein (AIP) 1 specifically enhances disassembly of actin-depolymerizing factor (ADF)/cofilin-bound actin filaments. In vitro, AIP1 actively disassembles filaments, caps barbed ends, and binds to the side of filaments. However, how AIP1 functions in the cellular actin cytoskeletal dynamics is not understood. We compared biochemical and in vivo activities of mutant UNC-78 proteins and found that impaired activity of mutant UNC-78 proteins to enhance disassembly of ADF/cofilin-bound actin filaments is associated with inability to regulate striated organization of actin filaments in muscle cells. Six functionally important residues are present in the N-terminal -propeller, whereas one residue is located in the C-terminal -propeller, suggesting the presence of two separate sites for interaction with ADF/cofilin and actin. In vitro, these mutant UNC-78 proteins exhibited variable alterations in actin disassembly and/or barbed end-capping activities, suggesting that both activities are important for its in vivo function. These results indicate that the actin-regulating activity of AIP1 in cooperation with ADF/cofilin is essential for its in vivo function to regulate actin filament organization in muscle cells.

Abbreviations used: ADF, actin-depolymerizing factor; AIP1, actin-interacting protein 1; GFP, green fluorescent protein: GST, glutathione S-transferase.

The online version of this article contains supplemental material at MBC Online (http://www.molbiolcell.org).

^* Present address: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.

Address correspondence to: Shoichiro Ono (sono{at}emory.edu).

This article has been cited by other articles:

				T. Klaavuniemi, S. Yamashiro, and S. Ono Caenorhabditis elegans Gelsolin-like Protein 1 Is a Novel Actin Filament-severing Protein with Four Gelsolin-like Repeats J. Biol. Chem., September 19, 2008; 283(38): 26071 - 26080. [Abstract] [Full Text] [PDF]

				K. Ono, S. Yamashiro, and S. Ono Essential role of ADF/cofilin for assembly of contractile actin networks in the C. elegans somatic gonad J. Cell Sci., August 15, 2008; 121(16): 2662 - 2670. [Abstract] [Full Text] [PDF]

				S. Yamashiro, M. Gimona, and S. Ono UNC-87, a calponin-related protein in C. elegans, antagonizes ADF/cofilin-mediated actin filament dynamics J. Cell Sci., September 1, 2007; 120(17): 3022 - 3033. [Abstract] [Full Text] [PDF]

				N. Ren, J. Charlton, and P. N. Adler The flare Gene, Which Encodes the AIP1 Protein of Drosophila, Functions to Regulate F-Actin Disassembly in Pupal Epidermal Cells Genetics, August 1, 2007; 176(4): 2223 - 2234. [Abstract] [Full Text] [PDF]

				J. B. Moseley and B. L. Goode The Yeast Actin Cytoskeleton: from Cellular Function to Biochemical Mechanism Microbiol. Mol. Biol. Rev., September 1, 2006; 70(3): 605 - 645. [Abstract] [Full Text] [PDF]