MOLECULAR BIOLOGY OF TRANSFERRIN RECEPTOR EXPRESSION

尽管很明显转铁蛋白受体部分是由 细胞内的铁，也很明显，其他调节机制是 牵涉其中。由于对转铁蛋白受体基因的探测最近 我们正在利用分子生物学技术来研究 转铁蛋白受体在分子水平的表达调控。 该项目的一部分涉及对小鼠浆细胞瘤基因的研究。我们 已发现在这些细胞中有两个转铁蛋白受体mRNAs。 一条消息缺少全长mRNA的未翻译部分，而 保留蛋白质的编码序列。 利用这个模型系统，我们计划研究铁的调节能力 在消息水平上的TFR mRNA水平。我们将确定是否 信息中未翻译的部分是铁监管所必需的。 该项目的另一部分涉及对转铁蛋白受体基因的调控。 CAMP在HL-60细胞中的转录。我们已经证明营地已经关闭 C-myc和Tfr在添加后30‘-2小时内转录。我们 将调查这种关闭的机制并确定c-myc 基因对转铁蛋白受体基因的转录有影响。

Although it is clear that transferrin receptors are regulated in part by intracellular iron, it is also clear that other regulating mechanisms are involved. Since probes to the transferrin receptor gene have recently become available, we are utilizing molecular biology techniques to study the regulation of transferrin receptor expression at the molecular level. One part of this project involves the study of mouse plasmacytoma mRNA. We have found that there are two transferrin receptor mRNAs in these cells. One message lacks the untranslated part of the full-length mRNA, while retaining the coding sequences for the protein. Using this model system, we plan to study the ability of iron to regulate TfR mRNA levels at the level of the message. We will determine if the untranslated part of the message is necessary for iron regulation. Another part of the project involves the regulation of TfR gene transcription in HL-60 cells by cAMP. We have shown that cAMP shuts off transcription of both c-myc and TfR within 30' - 2 hrs after addition. We will investigate the mechanism of this shut-off and determine if the c-myc gene has any effect on transcription of the TfR gene.