The concentrations of AcSDKP, a physiological inhibitor of cell proliferation, vary during oogenesis and early development in Xenopus laevis.
The endogenous tetrapeptide AcSer-Asp-Lys-Pro (AcSDKP) is present in the circulation and cells of mammals. Extracellular AcSDKP is a negative regulator of cell proliferation inhibiting the S phase entry of numerous cell types such as hematopoietic progenitors, hepatocytes, lymphocytes and several continuous cell lines. In contrast, the biological role of cellular AcSDKP remains unknown. We have recently reported a decrease of cellular AcSDKP concentrations by 50% accompanying the initiation of DNA synthesis in mitogen-induced proliferation of human lymphocytes. In the present study we measured the variations of cellular AcSDKP concentrations during oogenesis and early development of Xenopus. Cellular AcSDKP concentrations peaked at stage IV of oogenesis and then continuously decreased during the final oocyte maturation and during the initial 15-h period of exponential cell division of the embryo. Altogether, our present and previously published data suggest that cellular AcSDKP may be involved in the regulation of cell proliferation in eukaryotic species.
Volkov
L
L
Laboratoire d'Hématologie Expérimentale, Faculté de Médecine, Limoges, France.
Comte
L
L
Frindel
E
E
Philippe
M
M
Praloran
V
V
D000595:Amino Acid Sequence; D000818:Animals; D002455:Cell Division; D002460:Cell Line; D005260:Female; D005306:Fertilization; D006131:Growth Inhibitors / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism*; D009866:Oogenesis; D014982:Xenopus laevis / Q000378:metabolism*; D015053:Zygote / Q000378:metabolism
D006131:Growth Inhibitors; D009842:Oligopeptides; C058504:goralatide