title: Accumulation of profilin II at the surface of Listeria is concomitant with the onset of motility and correlates with bacterial speed.
abstract: The spatial and temporal activity of the actin cytoskeleton is precisely regulated during cell motility by several microfilament-associated proteins of which profilin plays an essential role. We have analysed the distribution of green fluorescent protein (GFP)-tagged profilins in cultured and in Listeria-infected cells. Among the different GFP-profilin fusion proteins studied, only the construct in which the GFP moiety was fused to the carboxy terminus of profilin II (profilin II-GFP) was recruited by intracellular Listeria. The in vitro ligand-binding properties of this construct, e.g. the binding to monomeric actin, poly-L-proline and phosphatidylinositol 4,5-bisphosphate (PIP2), were unaffected by GFP. Profilin II-GFP co-localised with vinculin and Mena to the focal adhesions in REF-52 fibroblasts and was distributed as a thin line at the front of protruding lamellipodia in B16-F1 mouse melanoma cells. In Listeria-infected cells, profilin II-GFP was recruited, in an asymmetric fashion, to the surface of Listeria at the onset of motility whereas it was not detectable on non-motile bacteria. In contrast to the vasodilator-stimulated phosphoprotein (VASP), profilin II-GFP localised at the bacterial surface only on motile Listeria. Moreover, the fluorescence intensity of profilin II-GFP directly correlated with the speed of the bacteria. Thus, the use of GFP-tagged profilin II provides new insights into the role of profilins in cellular motility.
authors.affiliation: Department of Cell Biology, Gesellschaft für Biotechnologische Forschung (GBF), Mascheroder Weg 1, D-38124 Braunschweig, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Geese
authors.forename: K
authors.initials: K
authors.lastname: Schlüter
authors.forename: M
authors.initials: M
authors.lastname: Rothkegel
authors.forename: B M
authors.initials: BM
authors.lastname: Jockusch
authors.forename: J
authors.initials: J
authors.lastname: Wehland
authors.forename: A S
authors.initials: AS
authors.lastname: Sechi
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002465:Cell Movement; D003285:Contractile Proteins; D003599:Cytoskeleton / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000382:microbiology / Q000648:ultrastructure; D005656:Fungal Proteins / Q000378:metabolism; D008087:Listeria / Q000378:metabolism*; D008088:Listeriosis / Q000378:metabolism*; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D051304:Profilins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000378:metabolism; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D000199:Actins; D015815:Cell Adhesion Molecules; D003285:Contractile Proteins; D005656:Fungal Proteins; D008840:Microfilament Proteins; C100530:PIP2 protein, S cerevisiae; C495739:Pfn1 protein, mouse; C495742:Pfn2 protein, mouse; D010750:Phosphoproteins; D051304:Profilins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000098662:Vasodilator-Stimulated Phosphoprotein