TRANS-ACTIVATING FACTORS AND GLOBIN GENE EXPRESSION--A DIRECT APPROACH

人类经历了两次血红蛋白表型的发育转换。 胚胎在妊娠早期转变为胎儿，胎儿转变为成人 改变出生时间K562人白血病细胞系 表达除成人β-珠蛋白以外的所有珠蛋白基因。以前的工作 已经表明K562 β-珠蛋白基因的功能 通常在异源表达系统中。阐明机制 K562细胞中β-珠蛋白基因表达的失败可能提供了一个新的证据， 正常红细胞珠蛋白基因表达和转换研究进展 细胞 建立了一种稳定的转移子定位方法 赋予珠蛋白上游区域组织特异性的序列 基因.我们已经表明，104个碱基对的帽位点5'的， ε-珠蛋白基因足以用于组织特异性表达。稳定 K562细胞的转化体，其含有整合的组成型表达 HTLV-1 TAX 1基因已被开发。这些细胞显示出一种刺激， α、ζ、表位和γ珠蛋白基因。 这与 联苯胺阳性%增加，并通过免疫荧光法测量 血红蛋白。

Humans undergo two developmental switches in their hemoglobin phenotype. The embryonic to fetal switch early in gestation and the fetal to adult switch around the time of birth. The K562 human leukemia cell line expresses all globin genes other than the adult beta-globin. Previous work from this laboratory has shown that the K562 beta-globin gene functions normally in a heterologous expression system. Elucidation of the mechanism of failure of beta-globin gene expression in K562 cells may provide an insight into globin gene expression and switching in normal erythroid cells. A stable transferrant assay has been established to study the localization of sequences conferring tissue specificity to the upstream region of globin genes. We have shown that the 104 base pairs 5' of the cap site of the epsilon-globin gene are sufficient for tissue specific expression. Stable transformants of K562 cells containing integrated constitutively expressing HTLV-1 TAX1 genes have been developed. These cells display a stimulation of alpha, zeta, episilon, and gamma globin genes. This is correlated with increased % benzidine positivity and spectrophotometrically measured hemoglobin.