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

Vol. 17, Issue 6, 2722-2734, June 2006

This Article Full Text Full Text (PDF) Supplemental Material All Versions of this Article: E06-02-0114v1 17/6/2722    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 Ono, K. Articles by Ono, S. Search for Related Content PubMed PubMed Citation Articles by Ono, K. Articles by Ono, S.

Caenorhabditis elegans Kettin, a Large Immunoglobulin-like Repeat Protein, Binds to Filamentous Actin and Provides Mechanical Stability to the Contractile Apparatuses in Body Wall Muscle

Department of Pathology, Emory University, Atlanta, GA 30322

Submitted February 7, 2006; Revised March 9, 2006; Accepted March 23, 2006
Monitoring Editor: Thomas Pollard

Kettin is a large actin-binding protein with immunoglobulin-like (Ig) repeats, which is associated with the thin filaments in arthropod muscles. Here, we report identification and functional characterization of kettin in the nematode Caenorhabditis elegans. We found that one of the monoclonal antibodies that were raised against C. elegans muscle proteins specifically reacts with kettin (Ce-kettin). We determined the entire cDNA sequence of Ce-kettin that encodes a protein of 472 kDa with 31 Ig repeats. Arthropod kettins are splice variants of much larger connectin/titin-related proteins. However, the gene for Ce-kettin is independent of other connectin/titin-related genes. Ce-kettin localizes to the thin filaments near the dense bodies in both striated and nonstriated muscles. The C-terminal four Ig repeats and the adjacent non-Ig region synergistically bind to actin filaments in vitro. RNA interference of Ce-kettin caused weak disorganization of the actin filaments in body wall muscle. This phenotype was suppressed by inhibiting muscle contraction by a myosin mutation, but it was enhanced by tetramisole-induced hypercontraction. Furthermore, Ce-kettin was involved in organizing the cytoplasmic portion of the dense bodies in cooperation with -actinin. These results suggest that kettin is an important regulator of myofibrillar organization and provides mechanical stability to the myofibrils during contraction.

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)

Abbreviations used: GST, glutathione S-transferase; Ig, immunoglobulin-like; RNAi, RNA interference.

This article has been cited by other articles:

				H.-F. Han and M. C. Beckerle The ALP-Enigma Protein ALP-1 Functions in Actin Filament Organization to Promote Muscle Structural Integrity in Caenorhabditis elegans Mol. Biol. Cell, May 1, 2009; 20(9): 2361 - 2370. [Abstract] [Full Text] [PDF]

				S. Yamashiro, E. A. Cox, D. L. Baillie, J. D. Hardin, and S. Ono Sarcomeric actin organization is synergistically promoted by tropomodulin, ADF/cofilin, AIP1 and profilin in C. elegans J. Cell Sci., December 1, 2008; 121(23): 3867 - 3877. [Abstract] [Full Text] [PDF]

				R. D. S. Dixon, D. K. Arneman, A. S. Rachlin, N. R. Sundaresan, M. J. Costello, S. L. Campbell, and C. A. Otey Palladin Is an Actin Cross-linking Protein That Uses Immunoglobulin-like Domains to Bind Filamentous Actin J. Biol. Chem., March 7, 2008; 283(10): 6222 - 6231. [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]