title: Characterization of p70 S6 kinase 1 in early development of mouse embryos.
abstract: The mTOR kinase controls cell growth, proliferation, and survival through two distinct multiprotein complexes mTORC1 and mTORC2. p70 S6 Kinase 1 (S6K1) is characterized as downstream effector of mTOR. Until recently, the connection between S6K1 and mTORC1 /mTORC2 during the early development of mouse embryos has not been well elucidated. Here, the expression level of total S6K1 and its phosphorylation at Thr389 was determined in four phases of one-cell embryos. S6K1 was active throughout the cell cycle especially with higher activity in G2 and M phases. Rapamycin decreased the activity of M-phase promoting factor (MPF) and delayed the first mitotic cleavage. Down-regulating mTOR and raptor reduced S6K1 phosphorylation at Thr389 in one-cell embryos. Furthermore, rapamycin and microinjection of raptor shRNA decreased the immunofluorescent staining of Thr389 phospho-S6K1. It is proposed that mTORC1 may be involved in the control of MPF by regulating S6K1 during the early development of mouse embryos.
authors.affiliation: Department of Pathophysiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning Province, PR China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Xu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Su
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yan-Qiu
authors.initials: YQ
authors.lastname: Yu
authors.forename: Yan-Xiao
authors.initials: YX
authors.lastname: Li
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Zong
authors.forename: Bing-Zhi
authors.initials: BZ
authors.lastname: Yu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D002478:Cells, Cultured; D002970:Cleavage Stage, Ovum / Q000187:drug effects / Q000378:metabolism; D004622:Embryo, Mammalian; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008297:Male; D000076222:Mechanistic Target of Rapamycin Complex 1; D000090204:Mesothelin; D051379:Mice; D046912:Multiprotein Complexes; D010766:Phosphorylation / Q000187:drug effects; D011506:Proteins; D034741:RNA, Small Interfering / Q000494:pharmacology; D000076223:Regulatory-Associated Protein of mTOR; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000235:genetics* / Q000378:metabolism; D020123:Sirolimus / Q000494:pharmacology; D058570:TOR Serine-Threonine Kinases; D014018:Tissue Distribution; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C000715528:Msln protein, mouse; D046912:Multiprotein Complexes; D011506:Proteins; D034741:RNA, Small Interfering; D000076223:Regulatory-Associated Protein of mTOR; C540162:Rptor protein, mouse; D014157:Transcription Factors; D000076222:Mechanistic Target of Rapamycin Complex 1; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; D000090204:Mesothelin; D020123:Sirolimus