Yeh J R, Huang C, Wu D A, Guo I C, Rainey W E, Chung B C
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, China.
J Steroid Biochem Mol Biol. 1995 Jun;53(1-6):47-51. doi: 10.1016/0960-0760(95)00020-z.
Ferredoxin is an electron transport intermediate for all the mitochondrial cytochromes P450. It is especially abundant in steroidogenic organs where it functions in steroid biosynthesis. The regulation of ferredoxin gene expression was studied in both steroidogenic and nonsteroidogenic cell lines. In steroidogenic cell line Y1, the expression of ferredoxin was stimulated by cAMP and repressed slightly by angiotensin II and phorbol ester PMA. These drugs exhibited the same effect on the basal promoter of the ferredoxin gene, which includes one TATA box and an SP1 site. In human adrenocortical cell line H295, the stimulation of the ferredoxin gene by cAMP was blocked by cycloheximide, as observed in bovine adrenocortical cell culture. In nonsteroidogenic cell lines such as HeLa and COS-1, the stimulation of ferredoxin gene expression by cAMP was not observed, although basal expression was strong. Transfection studies showed that the ferredoxin promoter could not be stimulated by cAMP in nonsteroidogenic cells. Therefore the steroidogenic cell-specific regulation and the general expression pattern appears to be a property unique to the ferredoxin gene.
铁氧化还原蛋白是所有线粒体细胞色素P450的电子传递中间体。它在类固醇生成器官中特别丰富，在类固醇生物合成中发挥作用。在类固醇生成和非类固醇生成细胞系中都研究了铁氧化还原蛋白基因表达的调控。在类固醇生成细胞系Y1中，铁氧化还原蛋白的表达受到cAMP的刺激，并受到血管紧张素II和佛波酯PMA的轻微抑制。这些药物对铁氧化还原蛋白基因的基础启动子表现出相同的作用，该启动子包括一个TATA盒和一个SP1位点。在人肾上腺皮质细胞系H295中，cAMP对铁氧化还原蛋白基因的刺激被环己酰亚胺阻断，如在牛肾上腺皮质细胞培养中观察到的那样。在非类固醇生成细胞系如HeLa和COS-1中，虽然基础表达很强，但未观察到cAMP对铁氧化还原蛋白基因表达的刺激。转染研究表明，在非类固醇生成细胞中，cAMP不能刺激铁氧化还原蛋白启动子。因此，类固醇生成细胞特异性调控和一般表达模式似乎是铁氧化还原蛋白基因独有的特性。
