title: Expression analyses and transcriptional regulation of mouse nucleolar spindle-associated protein gene in erythroid cells: essential role of NF-Y.
abstract: Nucleolar spindle-associated protein (NuSAP), a recently characterised microtubule-associated protein, appears to participate in cell cycle regulation. It has been demonstrated that NuSAP is expressed preferentially in the erythroid lineage in haematopoietic cells. To characterise its role in erythropoiesis, we examined the expression profile of the NuSAP gene. In fractionated murine erythroblasts, NuSAP mRNA was remarkably more abundant in the subset corresponding to immature erythroblasts (TER119(+)CD71(high)) than mature erythroblasts (TER119(+)CD71(low)), and it was significantly increased in TER119(+) cells from in vivo phlebotomised mice compared with control mice. Furthermore, during erythroid maturation of mouse erythroleukaemia (MEL) cells by dimethylsulfoxide, NuSAP mRNA was increased at 24-72 h. These results suggested that the NuSAP gene might contribute to the expansion of immature erythroblast pool. The regulatory mechanism of NuSAP gene was investigated using MEL cells. Sequence analysis revealed that NuSAP promoter has four CCAAT boxes, an Sp1 element, a GATA-like element, a CACCC element, a Myb element and lacks a TATA box. Promoter analyses demonstrated that duplicated CCAAT boxes located at -81/-85 and -30/-34 were essential for promoter activity. Furthermore, the promoter was trans-activated by NF-YA through these elements. These results suggest that NuSAP might play an important role in erythroid proliferation under the control of NF-Y.
authors.affiliation: Department of Rheumatology and Haematology, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Hideo
authors.initials: H
authors.lastname: Harigae
authors.forename: Yoko
authors.initials: Y
authors.lastname: Okitsu
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Minami F
authors.initials: MF
authors.lastname: Yamada
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ishizawa
authors.forename: Junichi
authors.initials: J
authors.lastname: Kameoka
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kaku
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D000818:Animals; D023081:CCAAT-Binding Factor / Q000502:physiology*; D049109:Cell Proliferation; D004900:Erythroblasts / Q000378:metabolism*; D004920:Erythropoiesis / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis / Q000235:genetics*; D010957:Plasmids; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D023081:CCAAT-Binding Factor; D008869:Microtubule-Associated Proteins; C478323:NuSAP protein, mouse; D012333:RNA, Messenger