Structural and functional similarities between the human cytoskeletal protein zyxin and the ActA protein of Listeria monocytogenes.
The intracellular bacterial parasite Listeria monocytogenes produces ActA protein at its surface to facilitate the localized assembly of actin-filled comets that are required for movement. The organization of actin in Listeria comets shows striking similarity to the organization of actin at the plasma membrane of mammalian cells. Therefore we examined the possibility that an ActA-like protein is present in mammalian cells. By using antibodies directed against ActA, we identified zyxin as an ActA related protein in a number of cell types. We compared the functions of ActA and zyxin by transient expression of variants tagged with an inner plasma membrane localization sequence (a CAAX box). Targeting of the proline rich domain of zyxin to the plasma membrane disrupts the actin cytoskeleton and cell shape in a manner similar to that which occurs with membrane-targeted ActA sequences. A chimeric protein composed of the N-terminal domain of ActA fused to the N-terminal and central domains of zyxin induced a full ActA response in cells. Furthermore, zyxin and ActA exhibit common protein partners in vitro. On the basis of the shared properties of zyxin and ActA, we propose that zyxin enhances actin organizing activity in mammalian cells.
Golsteyn
R M
RM
Morphogènese et Signalisation Cellulaires, Centre National de la Recherche Scientifique, UMR 144, Institut Curie, Paris, France.
Beckerle
M C
MC
Koay
T
T
Friederich
E
E
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D001483:Base Sequence; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D006023:Glycoproteins; D006367:HeLa Cells; D006801:Humans; D008089:Listeria monocytogenes / Q000378:metabolism*; D008322:Mammals; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D008667:Metalloproteins / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D016324:Sequence Tagged Sites; D014162:Transfection; D016335:Zinc Fingers; D060589:Zyxin
D000199:Actins; D000906:Antibodies; D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D008565:Membrane Proteins; D008667:Metalloproteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; C092842:ZYX protein, human; D060589:Zyxin; C072980:actA protein, Listeria monocytogenes