Protein phosphorylation during 5-hydroxytryptamine-induced maturation of Spisula oocytes.
Maturation was induced in Spisula oocytes with 5-hydroxytryptamine (5-HT) creatinine sulfate at a final concentration of 5 microM. After 10 and 30 min of treatment, oocytes were homogenized and the cytosolic and particulate fractions were prepared. The fractions were incubated with [gamma-32P]GTP and [gamma-32P]ATP. The phosphorylated proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The radioactivity in the gels was determined by autoradiography. With [gamma-32P]GTP a marked increase in the radiolabeling of proteins with an estimated Mr of 47,000 and 20,000 in the cytosolic and particulate fractions, respectively, was demonstrated with the 5-HT-treated oocytes, whereas no stimulation was demonstrable with the use of [gamma-32P]ATP. A significant increase in GTP-mediated protein phosphorylation occurred within 10 min after 5-HT treatment before the occurrence of germinal vesicle breakdown, suggesting that this post-translation modification of proteins is an early action of the neurotransmitter in the induction of meiotic reinitiation in oocytes.
Haneji
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T
Center for Biomedical Research, Population Council, New York, New York 10021.
Koide
S S
SS
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D049872:Bivalvia; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006160:Guanosine Triphosphate / Q000378:metabolism; D008970:Molecular Weight; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D012701:Serotonin / Q000494:pharmacology*
D010750:Phosphoproteins; D012701:Serotonin; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate