Expression and modification of PKA and AKAPs during meiosis in rat oocytes.
Meiosis in oocytes is initiated during fetal life, arrested around birth and resumed after puberty. Meiotic arrest is controlled by a cAMP-dependent protein kinase (PKA)-mediated cAMP action. We examined oocytes for the presence and modulation of the regulatory (R) subunits of PKA and the A-kinase anchoring proteins (AKAPs) that target PKA to specific subcellular locations. We found that rat oocytes express the two regulatory subunit isoforms, RI and RII of PKA. Immunocytochemistry revealed that the regulatory subunits underwent cellular translocation upon resumption of meiosis. We also demonstrated the presence of a novel 140 kDa AKAP, AKAP140 that exhibited a retarded electrophoretic motility at reinitiation of meiosis. The mobility shift of AKAP140 was susceptible to alkaline phosphatase and prevented by inhibition of p34cdc2 kinase. We conclude that rat oocytes express AKAP140 that is phosphorylated during meiosis. AKAP140 phosphorylation is sensitive to p34cdc2 kinase inhibitors. We hypothesize that AKAP140 and its phosphorylation state may influence the translocation of the R subunits of PKA throughout resumption of meiosis.
Kovo
M
M
Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, Israel.
Schillace
R V
RV
Galiani
D
D
Josefsberg
L B
LB
Carr
D W
DW
Dekel
N
N
D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002352:Carrier Proteins / Q000502:physiology*; D002451:Cell Compartmentation; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004790:Enzyme Induction; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D020935:MAP Kinase Signaling System; D016200:Maturation-Promoting Factor / Q000502:physiology; D008540:Meiosis; D019319:Okadaic Acid / Q000494:pharmacology; D009865:Oocytes / Q000378:metabolism*; D010766:Phosphorylation; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D011499:Protein Processing, Post-Translational; D051381:Rats; D017208:Rats, Wistar; D013347:Subcellular Fractions / Q000201:enzymology
D054758:A Kinase Anchor Proteins; C471068:A-kinase anchor protein 140, rat; D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D020033:Protein Isoforms; D019319:Okadaic Acid; D017868:Cyclic AMP-Dependent Protein Kinases; D016203:CDC2 Protein Kinase; D016200:Maturation-Promoting Factor