Regulation of coiled-coil assembly in tropomyosins

Araya, E., Berthier, C., Kim, E., Yeung, T., Wang, X. R., Helfman, D. M. (January 2002) Regulation of coiled-coil assembly in tropomyosins. Journal of Structural Biology, 137 (1-2). pp. 176-183. ISSN 1047-8477

URL: http://www.ncbi.nlm.nih.gov/pubmed/12064944
DOI: 10.1006/jsbi.2002.4463

Abstract

Tropomyosins (TMs) are a family of actin filament-binding proteins. They consist of nearly 100% α-helix and assemble into parallel coiled-coil dimers. In vertebrates, TMs are encoded by four genes that give rise to at least 17 distinct isoforms through the use of alternative RNA splicing and alternative promoters. We have studied various aspects of the coiled-coil interactions among muscle and nonmuscle isoforms by the use of transfection of epitope-tagged constructs, followed by immunoprecipitation, SDS–PAGE, and Western blot analyses. For coiled-coil interactions between high-molecular-weight isoforms (284 amino acids), the information for homo- versus heterodimerization is contained in large part within the alternatively spliced exons of nonmuscle and muscle (skeletal and smooth) isoforms. Furthermore, sequences located in alternatively spliced exons encoding amino acids 39–80 (exons 2a/2b), amino acids 189–213 (exons 6a/6b), and amino acids 258–284 (exons 9a/9d) are critical for the selective formation of homo- versus heterodimers. Among low-molecular-weight isoforms (248 amino acids), TM-4 and TM-5 can form either homodimers or heterodimers. The trigger sequence (amino acids 190–202) is required for homodimerization of TM-4, but not heterodimerization of TM-4 with TM-5. How the dimeric state of TMs might play a role in their cellular localization and function is discussed.

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > actin
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > cytoskeletal proteins
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types
CSHL Authors:
Communities: CSHL labs > Helfman lab
Depositing User: Matt Covey
Date: January 2002
Date Deposited: 09 Jan 2014 15:12
Last Modified: 09 Jan 2014 15:12
Related URLs:
URI: http://repository.cshl.edu/id/eprint/28663

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