Rutherford T R, Harrison P R
Proc Natl Acad Sci U S A. 1979 Nov;76(11):5660-4. doi: 10.1073/pnas.76.11.5660.
Friend erythroleukemia cells of line Fw are noninducible for hemoglobin synthesis by dimethyl sulfoxide, butyric acid, and other agents. However, these agents were found to induce hemoglobin synthesis if the cells were also treated with exogenous hemin. Butyric acid (or, to a lesser extent, dimethyl sulfoxide) by itself induced accumulation of the erythroid-specific membrane protein spectrin. The basis of the control of globin gene expression by hemin was investigated. Hemin does not control globin and total protein synthesis via the action of the hemin-controlled repressor. Rather, hemin, alone or in combination with dimethyl sulfoxide, induces accumulation of globin mRNA and nuclear globin RNA sequences. Direct measurements of heme synthesis indicate that Fw cells may be significantly deficient in heme metabolism.
Fw系的Friend红白血病细胞对二甲基亚砜、丁酸和其他试剂诱导血红蛋白合成不敏感。然而,如果这些细胞同时用外源性血红素处理,就会发现这些试剂能诱导血红蛋白合成。丁酸(或程度稍轻的二甲基亚砜)自身可诱导红系特异性膜蛋白血影蛋白的积累。研究了血红素对珠蛋白基因表达的调控基础。血红素并非通过血红素控制的阻遏物的作用来控制珠蛋白和总蛋白的合成。相反,血红素单独或与二甲基亚砜联合使用时,可诱导珠蛋白mRNA和核珠蛋白RNA序列的积累。血红素合成的直接测量表明,Fw细胞可能在血红素代谢方面存在显著缺陷。