Maternally recruited Aurora C kinase is more stable than Aurora B to support mouse oocyte maturation and early development.
Aurora kinases are highly conserved, essential regulators of cell division. Two Aurora kinase isoforms, A and B (AURKA and AURKB), are expressed ubiquitously in mammals, whereas a third isoform, Aurora C (AURKC), is largely restricted to germ cells. Because AURKC is very similar to AURKB, based on sequence and functional analyses, why germ cells express AURKC is unclear. We report that Aurkc(-/-) females are subfertile, and that AURKB function declines as development progresses based on increasing severity of cytokinesis failure and arrested embryonic development. Furthermore, we find that neither Aurkb nor Aurkc is expressed after the one-cell stage, and that AURKC is more stable during maturation than AURKB using fluorescently tagged reporter proteins. In addition, Aurkc mRNA is recruited during maturation. Because maturation occurs in the absence of transcription, posttranscriptional regulation of Aurkc mRNA, coupled with the greater stability of AURKC protein, provides a means to ensure sufficient Aurora kinase activity, despite loss of AURKB, to support both meiotic and early embryonic cell divisions. These findings suggest a model for the presence of AURKC in oocytes: that AURKC compensates for loss of AURKB through differences in both message recruitment and protein stability.
Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Karen
K
Schindler
Olga
O
Davydenko
Brianna
B
Fram
Michael A
MA
Lampson
Richard M
RM
Schultz
D000818:Animals; D064096:Aurora Kinase A; D064107:Aurora Kinase B; D064108:Aurora Kinase C; D064127:Aurora Kinases; D001483:Base Sequence; D004622:Embryo, Mammalian / Q000166:cytology / Q000201:enzymology; D047108:Embryonic Development; D004795:Enzyme Stability; D005260:Female; D008540:Meiosis; D051379:Mice; D008969:Molecular Sequence Data; D009865:Oocytes / Q000166:cytology* / Q000201:enzymology*; D009866:Oogenesis; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D059748:Proteolysis; D023121:RNA, Messenger, Stored / Q000235:genetics / Q000378:metabolism
D023121:RNA, Messenger, Stored; C576918:Aurka protein, mouse; C576924:Aurkb protein, mouse; C576928:Aurkc protein, mouse; D064096:Aurora Kinase A; D064107:Aurora Kinase B; D064108:Aurora Kinase C; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases