Expression analyses and transcriptional regulation of mouse nucleolar spindle‐associated protein gene in erythroid cells: essential role of NF‐Y

• Published in: British journal of haematology 2006-11, Vol.135 (4), p.583-590
• Main Authors: Fujiwara, Tohru, Harigae, Hideo, Okitsu, Yoko, Takahashi, Shinichiro, Yokoyama, Hisayuki, Yamada, Minami F, Ishizawa, Kenichi, Kameoka, Junichi, Kaku, Mitsuo, Sasaki, Takeshi
• Format: Article
• Language: English
• Subjects: 5' Flanking Region - genetics; Animals; Biological and medical sciences; CCAAT box; CCAAT-Binding Factor - physiology; cell cycle; Cell Proliferation; Erythroblasts - metabolism; erythroid cells; Erythropoiesis - genetics; Erythropoiesis - physiology; Gene Expression Regulation; Hematologic and hematopoietic diseases; Medical sciences; Mice; Microtubule-Associated Proteins - biosynthesis; Microtubule-Associated Proteins - genetics; NF‐Y; nucleolar spindle‐associated protein; Plasmids; RNA, Messenger - genetics; Transcription, Genetic; Tumor Cells, Cultured
• ISSN: 0007-1048; 1365-2141
• DOI: 10.1111/j.1365-2141.2006.06340.x

Summary 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+CD71high) than mature erythroblasts (TER119+CD71low), 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.