Phg2, a kinase involved in adhesion and focal site modeling in Dictyostelium.
The amoeba Dictyostelium is a simple genetic system for analyzing substrate adhesion, motility and phagocytosis. A new adhesion-defective mutant named phg2 was isolated in this system, and PHG2 encodes a novel serine/threonine kinase with a ras-binding domain. We compared the phenotype of phg2 null cells to other previously isolated adhesion mutants to evaluate the specific role of each gene product. Phg1, Phg2, myosin VII, and talin all play similar roles in cellular adhesion. Like myosin VII and talin, Phg2 also is involved in the organization of the actin cytoskeleton. In addition, phg2 mutant cells have defects in the organization of the actin cytoskeleton at the cell-substrate interface, and in cell motility. Because these last two defects are not seen in phg1, myoVII, or talin mutants, this suggests a specific role for Phg2 in the control of local actin polymerization/depolymerization. This study establishes a functional hierarchy in the roles of Phg1, Phg2, myosinVII, and talin in cellular adhesion, actin cytoskeleton organization, and motility.
Gebbie
Leigh
L
Université de Genève, Centre Médical Universitaire, Département de Morphologie, CH-1211 Genève 4, Switzerland.
Benghezal
Mohammed
M
Cornillon
Sophie
S
Froquet
Romain
R
Cherix
Nathalie
N
Malbouyres
Marilyne
M
Lefkir
Yaya
Y
Grangeasse
Christophe
C
Fache
Sébastien
S
Dalous
Jérémie
J
Brückert
Franz
F
Letourneur
François
F
Cosson
Pierre
P
D008841:Actin Cytoskeleton / Q000648:ultrastructure*; D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D048430:Cell Shape / Q000235:genetics / Q000502:physiology; D048749:Cytokinesis / Q000235:genetics / Q000502:physiology; D004023:Dictyostelium / Q000201:enzymology* / Q000502:physiology / Q000648:ultrastructure*; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009218:Myosins / Q000235:genetics / Q000502:physiology; D010587:Phagocytosis / Q000235:genetics / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000235:genetics / Q000502:physiology; D016608:Talin / Q000235:genetics / Q000502:physiology
D008565:Membrane Proteins; C416668:Phg1 protein, Dictyostelium discoideum; D015800:Protozoan Proteins; D016608:Talin; C407348:myosin VII protein, Dictyostelium discoideum; D017346:Protein Serine-Threonine Kinases; D009218:Myosins