title: Localization of the Rho GTPases and some Rho effector proteins in the sperm of several mammalian species.
abstract: The acrosome reaction is a fundamental event in the biology of the sperm and is a prerequisite to fertilization of the egg. Members of the Rho family of GTPases and their effectors are present in the cytoplasm and/or plasma membrane overlying the acrosome of porcine sperm. We have implicated the Rho family of GTPases and the Rho-activated kinase, ROCK-1, in mediating the zona-pellucida-induced acrosome reaction. Others have implicated the Rho GTPase in regulating the ionophore-induced acrosome reaction in the sperm of several mammalian species as well as in motility of bovine sperm. In this study, the localization of the Rho GTPases (RhoA, RhoB, Rac1 and Cdc42) as well as the effectors RhoGDI, PI(4)P5K and ROCK-1, was determined in boar, human, rat, ram, bull and elephant sperm. The four GTPases were each present in the sperm head of all species examined. RhoGDI was expressed in the head and tail of sperm from all species except pig, where it was present only in the head. PI(4)P5K was expressed in both head and tail of sperm from all species, but expression was typically weaker in the tail. Finally, ROCK-1 was expressed in the heads and tails of all sperm except that of the boar, where it was present only in the acrosomal region. These observations taken together suggest that the expression of Rho GTPases in sperm has been conserved throughout mammalian evolution, most likely due to the role of these GTPases in regulating acrosomal exocytosis.
authors.affiliation: Department of Animal Science, One Shields Avenue, University of California, Davis, Davis, CA 95616, USA. carld@pacrepro.com
authors.forename: Carl C
authors.initials: CC
authors.lastname: Ducummon
authors.forename: Trish
authors.initials: T
authors.lastname: Berger
mesh_terms: D000818:Animals; D002417:Cattle; D004606:Elephants; D020730:Guanine Nucleotide Dissociation Inhibitors / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D012756:Sheep; D013094:Spermatozoa / Q000201:enzymology*; D013552:Swine; D020741:rho GTP-Binding Proteins / Q000378:metabolism*; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha; D054460:rho-Associated Kinases; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors
chemical_list: C569638:ARHGDIA protein, human; D020730:Guanine Nucleotide Dissociation Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D020741:rho GTP-Binding Proteins