Steroidogenic enzymes, expression

Lala, D. S., Rice, D.A., and Parker, K. L. (1992). Steroidogenic factor I, a key regulator of steroidogenic enzyme expression, is the mouse homolog of fushi tarazu-factor I. Mol Endocrinol 6, 1249-1258. 

Compagnone NA, Bulfone A, Rubenstein JL, Mellon SH. 1995. Steroidogenic enzyme P450c 17 is expressed in the embryonic central nervous system. Endocrinology 136 5212-5223. 

Mellon SH, Deschepper CF. 1993. Neurosteroid biosynthesis genes for adrenal steroidogenic enzymes are expressed in the brain. Brain Res 629 283-292. 

Yu L, Romero DG, Gomez-Sanchez CE, Gomez-Sanchez EP. 2002. Steroidogenic enzyme gene expression in the human brain. Mol Cell Endocrinol 190 9-17. 

Fig. 7. Hypothesis for the action of ACTH in increasing the level of steroidogenic enzymes, in this case 17a-hydroxylase. In this model, cyclic AMP activates cyclic AMP-dependent protein kinase which by a series of unknown steps results in the accumulation of mRNA coding for a regulatory protein (17a-RP). After translation of this mRNA, the 17a-RP is hypothesized to translocate to the nucleus, where it activates the transcription of the cytochrome /M50,7 gene. This is one of several hypotheses which account for the sensitivity of cytochrome P-450 gene expression to inhibition of protein synthesis. From Ref. 27.

More recently, however, many laboratories have reported that nervous tissue is capable of expressing essential steroidogenic enzymes and therefore de novo synthesize steroid hormones, that are at least in part independent from classic steroidogenic tissues (Mellon and Griffin, 2002 Tsutsui et al., 2000). Moreover, the expression of StAR has also been detected in neural tissues (Lavaque et al., 2006 Sierra, 2004). Today, the term neurosteroid refers to... 

Cer can also modulate the activity and/or expression of steroidogenic enzymes. Meroni and colleagues have shown that Cer can regulate P450cl7a enzymatic activity as well as inhibit cAMP production (Meroni et al., 2000). In another report, Cer was identified as a novel regulator of llp-HSDl in... 

Kayes-Wandover, K.M. and P.C. White (2000). Steroidogenic enzyme gene expression in the human heart. J. Clin. Endocrinol. Metab. 85, 2519-2525. 

Hanukoglu, I. (1992). Steroidogenic enzymes Structure, function and regulation of expression. J. Steroid Biochem. Mol. Biol. 43, 779-804. 

The liver, placenta, and small intestines have also been reported as steroidogenic centers where a selective set of cytochrome P450 and HSD enzymes are expressed. CYPl7 is expressed in the rat liver and this expression fluctuates during development, indicating a pattern of expression exclusively tuned for the... 

Human P450 17A is expressed in steroidogenic tissues, including adrenals and gonads. The enzyme has also been reported in fetal kidney, thymus, and spleen. The enzyme has also been found in human (adult) heart and adipose tissue. ... 

Fig. 12.2 Steroidogenic pathways in the human testis and ovary. Similar to the ZR of the adrenal cortex, the Leydig cell (a) expresses only two P450 enzymes, P450scc and P450cl7, which enable testosterone production via redundant pathways. The ovary (b) uses two cell types to produce estrogens. The granulosa cells contain abundant P450scc and P450aro but little or no P450cl7, so these...

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