Cell type-specific roles for Cdc42, Rac, and RhoL in Drosophila oogenesis.
The Rho subfamily of GTPases has been shown to regulate cellular morphology. We report the discovery of a new member of the Rho family, named RhoL, which is equally similar to Rac, Rho, and Cdc42. Expression of a dominant-negative RhoL transgene in the Drosophila ovary caused nurse cells to collapse and fuse together. Mutant forms of Cdc42 mimicked this effect. Expression of constitutively active RhoL led to nurse cell subcortical actin breakdown and disruption of nurse cell-follicle cell contacts, followed by germ cell apoptosis. In contrast, Rac activity was specifically required for migration of a subset of follicle cells called border cells. All three activities were necessary for normal transfer of nurse cell cytoplasm to the oocyte. These results suggest that Rho protein activities have cell type-specific effects on morphogenesis.
Murphy
A M
AM
Department of Biological Chemistry, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205-2185, USA.
Montell
D J
DJ
D000199:Actins / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D004330:Drosophila / Q000166:cytology*; D029721:Drosophila Proteins; D005260:Female; D020558:GTP Phosphohydrolases / Q000378:metabolism / Q000502:physiology; D019204:GTP-Binding Proteins / Q000502:physiology*; D005854:Germ Cells / Q000166:cytology / Q000201:enzymology; D007301:Insect Hormones / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D009866:Oogenesis / Q000502:physiology*; D010063:Ovum / Q000166:cytology / Q000201:enzymology; D017386:Sequence Homology, Amino Acid; D020744:rac GTP-Binding Proteins
D000199:Actins; C090145:Cdc42 protein, Drosophila; D029721:Drosophila Proteins; D007301:Insect Hormones; D008565:Membrane Proteins; C090146:Rac1 protein, Drosophila; C081481:Rho protein, Drosophila; C472498:Stet protein, Drosophila; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020744:rac GTP-Binding Proteins