Cytokinesis arrest and redistribution of actin-cytoskeleton regulatory components in cells expressing the Rho GTPase CDC42Hs.
In mammalian cells, Rho GTPases control the reorganisation of the actin cytoskeleton in response to growth factors. In the cytoplasm, the polymerisation of actin filaments and their organisation into complex architectures is orchestrated by numerous proteins which act either directly, by interacting with actin, or by producing secondary messengers which serve as mediators between signal transduction pathways and the microfilament organisation. We sought to determine whether the intracellular distribution of some of these regulatory components may be controlled by the Rho GTPase CDC42Hs. With this aim, we have established HeLa-derived human cell lines in which expression of a constitutively activated mutant of CDC42Hs is inducible. Morphological analysis by immunofluorescence labelling and confocal laser scanning microscopy revealed a massive reorganisation of F-actin in cortical microspikes as well as podosome-like structures located at the ventral face of the cells. Concomitantly, the cells became giant and multinucleate indicating that cytokinesis was impaired. The actin bundling protein T-plastin, the vasodilatator-stimulated phosphoprotein (VASP), a profilin ligand, as well as the 85 kDa regulatory subunit of the phosphoinosite 3-kinase redistributed with F-actin into the CDC42Hs-induced structures.
Dutartre
H
H
Centre d'Immunologie INSERM/CNRS de Marseille Luminy, France.
Davoust
J
J
Gorvel
J P
JP
Chavrier
P
P
D000199:Actins / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism; D017931:DNA Primers; D004285:Dogs; D020558:GTP Phosphohydrolases / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism; D015398:Signal Transduction; D013752:Tetracycline / Q000494:pharmacology; D014162:Transfection; D016596:Vinculin / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein
D000199:Actins; D018797:Cell Cycle Proteins; D017931:DNA Primers; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; C026742:plastin; D016596:Vinculin; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein; D013752:Tetracycline