Journal
JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY
Volume 99, Issue 2-3, Pages 121-128Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jsbmb.2005.12.004
Keywords
P450scc; CYP11A1; steroidogenic enzyme; ovary; head kidney; Japanese eel
Ask authors/readers for more resources
Cholesterol side-chain cleavage cytochrome P450 (CYP11A1:P450scc) is a crucial steroidogenic enzyme that catalyzes an initial step in the production of all classes of steroids. A cDNA encoding Japanese eel P450scc was cloned and characterized. The cDNA putatively encoded 521 amino acid residues with high homology to those of other vertebrate forms. The recombinant P450scc produced in COS-7 cells efficiently catalyzed the conversion of 25-hydroxycholesterol into pregnenolone. By northern blot, a single P450scc transcript of approximately 3.3 kb was detected in both ovary and head kidney. Transcript levels of this enzyme significantly increased throughout ovarian development artificially induced by salmon pituitary homogenate, which suggests that gonadotropic stimuli can induce ovarian expression of the P450scc gene in teleosts, as has been reported in mammals. Furthermore, RT-PCR analysis revealed that gene expression of three steroidogenic enzymes, P450scc, P450c17 and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) show distinctly different tissue-specific patterns of expression in the Japanese eel. The P450scc gene was expressed in ovary and head kidney while the sole source of the P450c17 transcript was ovary. In contrast, 3P-HSD transcript was detected in all tissues examined, brain, liver, spleen and trunk kidney, etc. These suggest that some steroidogenic enzymes are also expressed in non-endocrine tissues and could potentially regulate the local and/or circulating steroid levels in teleosts, as they do in mammals. (c) 2006 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available