Tropomyosin assembly intermediates in the control of MF-system turnover
2008 (English)In: European Journal of Cell Biology, ISSN 0171-9335, Vol. 87, no 11, 905-920 p.Article in journal (Refereed) Published
Tropomyosin is a coiled-coil α-helical protein, which self-associates in a head-to-tail fashion along polymers of actin to produce thin filaments. Mammalian non-muscle cells express a large number of tropomyosin isoforms, which are differentially regulated during embryogenesis and associated with specialized actin microfilament ensembles in cells. The function of tropomyosin in specifying form and localization of these subcellular structures, and the precise mechanism(s) by which they carry out their functions, is unclear. This paper reports that, while the major fraction of non-muscle cell tropomyosin resides in actin thin filaments of the cytomatrix, the soluble part of the cytoplasm contains tropomyosins in the form of actin-free multimers, which are isoform specific and of high molecular weight (MWapp 180,000–250,000). Stimulation of motile cells with growth factors induces a rapid, actin polymerization-dependent outgrowth of lamellipodia and filopodia. Concomitantly, the levels of tropomyosin isoform-specific multimers decrease, suggesting their involvement in actin thin filament formation. Malignant tumor cells have drastically altered levels and composition of tropomyosin isoform-specific multimers as well as tropomyosin in the cytomatrix.
Place, publisher, year, edition, pages
2008. Vol. 87, no 11, 905-920 p.
Actin, Tropomyosin, Tropomyosin multimers, Lamellipodia, Filopodia, Tumorigenesis
IdentifiersURN: urn:nbn:se:su:diva-25021DOI: 10.1016/j.ejcb.2008.06.006ISI: 000260600800004OAI: oai:DiVA.org:su-25021DiVA: diva2:198733
Part of urn:nbn:se:su:diva-76332008-05-122008-05-022009-05-18Bibliographically approved