Xenopus homolog of the mos protooncogene transforms mammalian fibroblasts and induces maturation of Xenopus oocytes.
The oncogene v-mos transforms mammalian fibroblasts and encodes a serine/threonine protein kinase. Expression of the c-mos protooncogene is most abundant in germ cells, suggesting a normal role for c-mos in meiosis. Here we describe the isolation of cDNA clones containing the complete coding region of the Xenopus laevis homolog of c-mos (mosxe). The mosxe gene is transforming when introduced into murine NIH 3T3 cells, and transformation is abrogated by a lysine-to-arginine mutation in the canonical ATP-binding site. Microinjection of in vitro transcribed mosxe RNA into prophase-arrested Xenopus oocytes causes a resumption of meiosis, leading to germinal vesicle breakdown and oocyte maturation. Oocyte maturation was not observed after microinjection of in vitro transcribed mosxe RNA encoding the lysine-to-arginine mutation. These results demonstrate that the mosxe-encoded protein can induce progression through the cell cycle for both meiotic and mitotic cells and that this property is dependent on the presumptive ATP-binding domain in the protein kinase.
Freeman
R S
RS
Department of Chemistry, University of California, San Diego, La Jolla 92093.
Pickham
K M
KM
Kanki
J P
JP
Lee
B A
BA
Pena
S V
SV
Donoghue
D J
DJ
D000595:Amino Acid Sequence; D000818:Animals; D002471:Cell Transformation, Neoplastic; D002645:Chickens; D004247:DNA / Q000235:genetics*; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D051379:Mice; D008845:Microinjections; D008969:Molecular Sequence Data; D009154:Mutation; D009865:Oocytes / Q000502:physiology*; D014176:Protein Biosynthesis; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D017231:Proto-Oncogene Proteins c-mos; D011519:Proto-Oncogenes; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014981:Xenopus
D011518:Proto-Oncogene Proteins; D004247:DNA; D017231:Proto-Oncogene Proteins c-mos