cdc2 kinase sets a memory phosphorylation signal on elongation factor EF-1 delta during meiotic cell division, which perdures in early development.
EF-1 delta is a physiological substrate for cdc2 protein kinase in Xenopus oocytes. The protein is part of the nucleotide exchange factor EF-1 beta gamma delta, involved in the elongation step of protein synthesis. We show that EF-1 delta exists under four isoforms in the prophase oocyte, all phosphorylable by casein kinase II. Each of the prophase isoforms was further separated into a 36 and a 38 kDa form upon phosphorylation by cdc2 kinase which therefore reveals the existence of eight different isoforms. Phosphorylation by cdc2 kinase can be monitored as the electrophoretic mobility dedoublement 36/38 kDa. Developmental regulation of EF-1 delta was analyzed. The cdc2 kinase-induced change occures at meiotic division, after complete oogenesis and perdures during early development. It is therefore a phosphorylation memory signal for early development.
Minella
O
O
Laboratoire de Physiologie de la Reproduction, UPMC, CNRS URA 1449, INRA, Paris, France.
Cormier
P
P
Morales
J
J
Poulhe
R
R
Bellé
R
R
Mulner-Lorillon
O
O
D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D008540:Meiosis; D009865:Oocytes / Q000254:growth & development*; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000378:metabolism*; D010766:Phosphorylation; D014982:Xenopus laevis
D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D016203:CDC2 Protein Kinase