Al-Bader A A, Orengo A, Rao P N
Proc Natl Acad Sci U S A. 1978 Dec;75(12):6064-8. doi: 10.1073/pnas.75.12.6064.
The objective of this study was to determine if HeLa cells irreversibly arrested in G2 phase of the cell cycle by a brief exposure to a nitrosourea compound were deficient in certain proteins when compared with G2-synchronized cells. Total cellular proteins of G2-synchronized, G2-arrested, and S phase-synchronized cells were compared by two-dimensional polyacrylamide gel electrophoresis. The S phase cells differed from the G2-synchronized and G2-arrested cells by the absence of about 35 and 25 protein spots, respectively, of a total of nearly 150. At least nine protein spots in the molecular weight range of 4--5 X 10(4) that were present in the G2-synchronized cells were absent in both the G2-arrested and the S phase cells. Thus, these studies suggest that the missing proteins are probably necessary for the transition of cells from G2 phase to mitosis. Supplying the missing proteins to the G2-arrested cells by fusion with G2-synchronized cells facilitated the entry of the former into mitosis.
本研究的目的是确定与G2期同步化细胞相比，经短暂暴露于亚硝基脲化合物而不可逆地停滞在细胞周期G2期的HeLa细胞是否缺乏某些蛋白质。通过二维聚丙烯酰胺凝胶电泳比较了G2期同步化、G2期停滞和S期同步化细胞的总细胞蛋白质。S期细胞与G2期同步化细胞和G2期停滞细胞不同，在总共近150个蛋白质点中，分别缺少约35个和25个蛋白质点。在G2期同步化细胞中存在的分子量范围为4 - 5×10⁴的至少9个蛋白质点在G2期停滞细胞和S期细胞中均不存在。因此，这些研究表明，缺失的蛋白质可能是细胞从G2期过渡到有丝分裂所必需的。通过与G2期同步化细胞融合将缺失的蛋白质提供给G2期停滞细胞，促进了前者进入有丝分裂。
