An Atypical Tropomyosin in Drosophila with Intermediate Filament-like Properties.

TitleAn Atypical Tropomyosin in Drosophila with Intermediate Filament-like Properties.
Publication TypeJournal Article
Year of Publication2016
AuthorsCho A, Kato M, Whitwam T, Kim JHoon, Montell DJ
JournalCell Rep
Date Published2016 07 26
KeywordsActin Cytoskeleton, Actins, Animals, Cell Movement, Cytoskeleton, Drosophila, Epithelial Cells, Female, Germ Cells, Intermediate Filaments, Microtubules, Protein Isoforms, Tropomyosin

<p>A longstanding mystery has been the absence of cytoplasmic intermediate filaments (IFs) from Drosophila despite their importance in other organisms. In the course of characterizing the in vivo expression and functions of Drosophila Tropomyosin (Tm) isoforms, we discovered an essential but unusual product of the Tm1 locus, Tm1-I/C, which resembles an IF protein in some respects. Like IFs, Tm1-I/C spontaneously forms filaments in vitro that are intermediate in diameter between F-actin and microtubules. Like IFs but unlike canonical Tms, Tm1-I/C contains N- and C-terminal low-complexity domains flanking a central coiled coil. In vivo, Tm1-I/C forms cytoplasmic filaments that do not associate with F-actin or canonical Tms. Tm1-I/C is essential for collective border cell migration, in epithelial cells for proper cytoarchitecture, and in the germline for the formation of germ plasm. These results suggest that flies have evolved a distinctive type of cytoskeletal filament from Tm.</p>

Alternate JournalCell Rep
PubMed ID27396338
PubMed Central IDPMC4971881
Grant ListR01 GM073164 / GM / NIGMS NIH HHS / United States
R01 GM084947 / GM / NIGMS NIH HHS / United States