title: Tropomyosins are present in lamellipodia of motile cells.
abstract: This paper shows that high-molecular-weight tropomyosins (TMs), as well as shorter isoforms of this protein, are present in significant amounts in lamellipodia and filopodia of spreading normal and transformed cells. The presence of TM in these locales was ascertained by staining of cells with antibodies reacting with endogenous TMs and through the expression of hemaglutinin- and green fluorescent protein-tagged TM isoforms. The observations are contrary to recent reports suggesting the absence of TMs in regions,where polymerization of actin takes place, and indicate that the view of the role of TM in the formation of actin filaments needs to be significantly revised.
authors.affiliation: Department of Cell Biology, The Wenner-Gren Institute, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Louise
authors.initials: L
authors.lastname: Hillberg
authors.forename: Li-Sophie
authors.initials: LS
authors.lastname: Zhao Rathje
authors.forename: Maria
authors.initials: M
authors.lastname: Nyåkern-Meazza
authors.forename: Brian
authors.initials: B
authors.lastname: Helfand
authors.forename: Robert D
authors.initials: RD
authors.lastname: Goldman
authors.forename: Clarence E
authors.initials: CE
authors.lastname: Schutt
authors.forename: Uno
authors.initials: U
authors.lastname: Lindberg
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D018715:Microscopy, Video; D010750:Phosphoproteins / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D011554:Pseudopodia / Q000378:metabolism*; D051381:Rats; D014335:Tropomyosin / Q000235:genetics / Q000378:metabolism*; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D010750:Phosphoproteins; D020033:Protein Isoforms; D014335:Tropomyosin; D000098662:Vasodilator-Stimulated Phosphoprotein; D049452:Green Fluorescent Proteins