Rodríguez P, Viñuela J E, Alvarez-Fernández L, Buceta M, Vidal A, Domínguez F, Gómez-Márquez J
Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Santiago de Compostela, 15706 Santiago de Compostela, Galicia, Spain.
Biochem J. 1998 May 1;331 ( Pt 3)(Pt 3):753-61. doi: 10.1042/bj3310753.
Prothymosin alpha (ProTalpha) is an acidic nuclear protein the expression of which is related to the proliferation and differentiation processes in mammalian cells. In the present study we have stably transfected HL-60 cells, a biological system that allows the study of both proliferation and differentiation, with recombinant vectors encoding sense and antisense ProTalpha mRNA. In the HL-60 cell clones overexpressing ProTalpha we observed an acceleration in the growth rate, whereas expression of the antisense orientation showed the opposite effect. Moreover, cell-cycle analysis demonstrated that the G1-phase was shortened in the cells expressing the sense construct. Before studying how ProTalpha affects differentiation, we showed that the down-regulation of ProTalpha gene during differentiation occurs in all mammalian cell lines (HL-60, K562, U937, MEL C88, N2A and PC12) analysed. The biological effect evoked by the induction of the ProTalpha sense vector was the retardation of cell differentiation, although expression of the antisense construct showed no effect on differentiation. In conclusion, our findings provide evidence that ProTalpha is directly implicated in cellular proliferation and that the maintenance of high levels of ProTalpha inside HL-60 cells is incompatible with their ability to differentiate.
前胸腺素α（ProTα）是一种酸性核蛋白，其表达与哺乳动物细胞的增殖和分化过程相关。在本研究中，我们用编码正义和反义ProTα mRNA的重组载体稳定转染了HL-60细胞，这是一个能够研究增殖和分化的生物学系统。在过表达ProTα的HL-60细胞克隆中，我们观察到生长速率加快，而反义方向的表达则显示出相反的效果。此外，细胞周期分析表明，在表达正义构建体的细胞中G1期缩短。在研究ProTα如何影响分化之前，我们表明在所有分析的哺乳动物细胞系（HL-60、K562、U937、MEL C88、N2A和PC12）中，分化过程中ProTα基因均下调。诱导ProTα正义载体所引发的生物学效应是细胞分化延迟，尽管反义构建体的表达对分化没有影响。总之，我们的研究结果提供了证据，证明ProTα直接参与细胞增殖，并且HL-60细胞内高水平ProTα的维持与其分化能力不相容。
