Jensen M R, Factor V M, Zimonjic D B, Miller M J, Keck C L, Thorgeirsson S S
Division of Basic Sciences, National Cancer Institute, Bethesda, Maryland 20892, USA.
Genomics. 1997 Oct 15;45(2):297-303. doi: 10.1006/geno.1997.4947.
Cyclins play an essential role in the control of the cell cycle. In this study the murine cyclin G1 gene expression, structure, and chromosomal localization were examined. Genes with high homology to murine cyclin G1 were detected in various mammals, including human, monkey, rat, dog, cow, and rabbit, but not in yeast or chicken. Cyclin G1 gene was expressed in all murine tissues examined, with the highest levels in cardiac and skeletal muscle. A 10,366-bp genomic DNA fragment encompassing the promoter region and the 5'-flanking region of the gene was cloned and sequenced. Three putative binding sites for the myocyte enhancer factor-2 family of transcription factors were revealed. Furthermore, an upstream p53-binding site was localized to nucleotides -252 to -233 and a new putative p53-binding site was identified in the first intronic region at nucleotides 275 to 294. By fluorescence in situ hybridization, the cyclin G1 gene was mapped to mouse chromosome 11B1.1. This region is homologous with human chromosome 5q31-q32, consistent with the recent mapping of the human cyclin G1 gene to chromosome 5q32-q34. Localization of murine cyclin G1 will facilitate determination of gene linkage and the identification of synteny groups in mammals and of DNA elements in or near this gene that mediate its tissue expression or development-specific pattern of expression.
细胞周期蛋白在细胞周期调控中起着至关重要的作用。在本研究中，对小鼠细胞周期蛋白G1基因的表达、结构及染色体定位进行了检测。在包括人类、猴子、大鼠、狗、牛和兔子在内的多种哺乳动物中检测到了与小鼠细胞周期蛋白G1具有高度同源性的基因，但在酵母或鸡中未检测到。细胞周期蛋白G1基因在所检测的所有小鼠组织中均有表达，在心脏和骨骼肌中表达水平最高。克隆并测序了一个包含该基因启动子区域和5'侧翼区域的10366 bp基因组DNA片段。揭示了转录因子肌细胞增强因子-2家族的三个假定结合位点。此外，一个上游p53结合位点定位于核苷酸-252至-233处，并且在第一个内含子区域的核苷酸275至294处鉴定出一个新的假定p53结合位点。通过荧光原位杂交，将细胞周期蛋白G1基因定位于小鼠染色体11B1.1上。该区域与人类染色体5q31-q32同源，这与最近将人类细胞周期蛋白G1基因定位于染色体5q32-q34一致。小鼠细胞周期蛋白G1的定位将有助于确定基因连锁关系，并有助于鉴定哺乳动物中的同线性组以及该基因内或其附近介导其组织表达或发育特异性表达模式的DNA元件。
