title: Endogenous activity of cyclic nucleotide-dependent protein kinase in plasma membranes isolated from Strongylocentrotus purpuratus sea urchin sperm.
abstract: Activity of cyclic nucleotide-dependent protein kinase was investigated in flagellar plasma membranes of sea urchin sperm (S. purpuratus). Membranes incubated with [gamma-32P]ATP showed in the presence of 1 microM cAMP an increased phosphorylation in multiple polypeptides. Half maximal response was seen at 0.6 microM of cAMP. In contrast, higher concentrations (100 microM) of cGMP were required to cause the same amount of protein phosphorylation. 80% of the protein kinase activity stimulatable by cAMP was resistant to extraction by 10 mM EGTA and sonication but it was entirely recovered in a detergent-solubilized fraction. Membranes pretreated with 200 microM cAMP, ultracentrifuged and resuspended in buffer solution did not undergo cAMP-stimulated phosphorylation in their polypeptides. This study demonstrates that flagellar plasma membranes isolated from S. purpuratus sea urchin sperm have an endogenous cAMP-dependent protein kinase, which may be bound to the membrane via its regulatory subunit.
authors.affiliation: Instituto de Investigacion en Biologia Experimental, Facultad de Quimica, Universidad de Guanajuato, Guanajuato, GTO, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Garcia-Soto
authors.forename: L M
authors.initials: LM
authors.lastname: Araiza
authors.forename: M
authors.initials: M
authors.lastname: Barrios
authors.forename: A
authors.initials: A
authors.lastname: Darszon
authors.forename: J P
authors.initials: JP
authors.lastname: Luna-Arias
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000201:enzymology; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008297:Male; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D012617:Sea Urchins; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D000242:Cyclic AMP; D011494:Protein Kinases; D006152:Cyclic GMP