skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Inherent steroid 17α,20-lyase activity in defunct cytochrome P450 17A enzymes

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
National Institutes of Health (NIH)
OSTI Identifier:
1419885
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Biological Chemistry; Journal Volume: 293; Journal Issue: 2
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Gonzalez, Eric, Johnson, Kevin M., Pallan, Pradeep S., Phan, Thanh T. N., Zhang, Wei, Lei, Li, Wawrzak, Zdzislaw, Yoshimoto, Francis K., Egli, Martin, and Guengerich, F. Peter. Inherent steroid 17α,20-lyase activity in defunct cytochrome P450 17A enzymes. United States: N. p., 2017. Web. doi:10.1074/jbc.RA117.000504.
Gonzalez, Eric, Johnson, Kevin M., Pallan, Pradeep S., Phan, Thanh T. N., Zhang, Wei, Lei, Li, Wawrzak, Zdzislaw, Yoshimoto, Francis K., Egli, Martin, & Guengerich, F. Peter. Inherent steroid 17α,20-lyase activity in defunct cytochrome P450 17A enzymes. United States. doi:10.1074/jbc.RA117.000504.
Gonzalez, Eric, Johnson, Kevin M., Pallan, Pradeep S., Phan, Thanh T. N., Zhang, Wei, Lei, Li, Wawrzak, Zdzislaw, Yoshimoto, Francis K., Egli, Martin, and Guengerich, F. Peter. Wed . "Inherent steroid 17α,20-lyase activity in defunct cytochrome P450 17A enzymes". United States. doi:10.1074/jbc.RA117.000504.
@article{osti_1419885,
title = {Inherent steroid 17α,20-lyase activity in defunct cytochrome P450 17A enzymes},
author = {Gonzalez, Eric and Johnson, Kevin M. and Pallan, Pradeep S. and Phan, Thanh T. N. and Zhang, Wei and Lei, Li and Wawrzak, Zdzislaw and Yoshimoto, Francis K. and Egli, Martin and Guengerich, F. Peter},
abstractNote = {},
doi = {10.1074/jbc.RA117.000504},
journal = {Journal of Biological Chemistry},
number = 2,
volume = 293,
place = {United States},
year = {Wed Dec 06 00:00:00 EST 2017},
month = {Wed Dec 06 00:00:00 EST 2017}
}
  • The role of cAMP in the regulation of the amount and synthesis of cytochrome P-450 cholesterol side-chain cleavage (P-450scc) and cytochrome P-450 17 alpha-hydroxylase/C17-20 lyase P-450(17 alpha) was investigated in mouse Leydig cell cultures. In the absence of cAMP, the amount of immunoreactive P-450(17 alpha) decreased to less than 5% by day 4 and was undetectable between days 7 and 11. In contrast, the amount of immunoreactive P-450scc remained relatively constant throughout the same period. Treatment of Leydig cell cultures for 4 days with 0.05 mM 8-bromo-cAMP initiated on day 7 increased the amount of P-450(17 alpha) with relatively littlemore » effect on the amount of P-450scc. The rate of de novo synthesis of each of the P-450 enzymes was studied by determining (35S)methionine incorporation into newly synthesized protein. In the absence of cAMP, de novo synthesis of P-450(17 alpha) ceased while the rate of de novo synthesis of P-450scc increased with time in culture between days 2 and 11. Treatment with cAMP initiated on day 7 of culture caused a time-dependent increase in the rate of de novo synthesis of P-450(17 alpha) on days 9 and 11 equivalent to 40% and 60%, respectively, of that observed in freshly isolated Leydig cells. The rate of de novo synthesis of P-450scc was increased 2-fold relative to untreated cultures on days 9 and 11. De novo synthesis of P-450(17 alpha) ceased when cAMP was removed on day 11 and restored when cAMP was added again on day 13 of culture.« less
  • Several cytochrome P450-dependent arachidonic acid metabolites have been shown to affect Na+,K(+)-ATPase activity. In the present study, we tested the effect of omega- and omega - 1-hydroxylated products, i.e., 19- and 20-hydroxyeicosatetraenoic acids (19- and 20-HETE), on the K-induced relaxation in rat aortic rings. 19-HETE and 20-HETE increased the magnitude of the potassium-induced relaxation in a dose-dependent fashion (10(-7)-10(-5) M). The inhibitory effect of ouabain on the potassium-induced relaxation was reversed by both 19- and 20-HETE. In addition, indomethacin fully inhibited the stimulatory effect of 19- and 20-HETE on relaxation induced by potassium. Vascular ouabain-sensitive 86Rb uptake was also increasedmore » by 19- and 20-HETE. These observations suggest that 19- and 20-HETE stimulate vascular Na+,K(+)-ATPase via their conversion by cyclooxygenase to prostaglandin-like material.« less
  • P450c17 is the single enzyme mediating both 17..cap alpha..-hydroxylase (steroid 17..cap alpha..-monooxygenase, EC 1.14.99.9) and 17,20 lyase activities in the synthesis of steroid hormones. It has been suggested that different P450c17 isozymes mediate these activities in the adrenal gland and testis. The authors sequenced 423 of the 509 amino acids (83%) of the porcine adrenal enzyme; based on this partial sequence, a 128-fold degenerate 17-mer was synthesized and used to screen a porcine adrenal cDNA library. This yielded a 380-base cloned cDNA, which in turn was used to isolate several human adrenal cDNAs. The longest of these, lambda hac 17-2,more » is 1754 base pairs long and includes the full-length coding region, the complete 3'-untranslated region, and 41 bases of the 5'-untranslated region. This cDNA encodes a protein of 508 amino acids having a predicted molecular weight of 57,379.82. High-stringency screening of a human testicular cDNA library yielded a partial clone containing 1303 identical bases. RNA gel blots and nuclease S1-protection experiments confirm that the adrenal and testicular P450c17 mRNAs are indistinguishable. These data indicate that the testis possesses a P450c17 identical to that in the adrenal. The human amino acid sequence is 66.7% homologous to the corresponding regions of the porcine sequence, and the human cDNA and amino acid sequences are 80.1 and 70.3% homologous, respectively, to bovine adrenal P450c17 cDNA. Both comparisons indicate that a central region comprising amino acid residues 160-268 is hypervariable among these species of P450c17.« less
  • As a preliminary step in a 4-year biomonitoring program, sex steroid levels, gonad weights, and diameter of vitellogenic oocytes were measured in tomcod collected bimonthly from the Miramichi and Kouchibouguac rivers from September 1993 to September 1994. As well as the reproductive indices, hepatic levels of cytochrome P4501A mRNA (CYP1A mRNA) were also measured. The preparatory period for spawning began in September, with maximal steroid levels in November, and spawning took place from late December to January. The CYP1A mRNA levels in female tomcod appeared inversely related to plasma steroids, with the lowest amounts of CYP1A mRNA coinciding with maximalmore » steroids. The CYP1A mRNA levels in male tomcod did not exhibit this relationship. River-river comparisons of female tomcod showed significantly smaller vitellogenic oocytes in the Miramichi, along with lower plasma testosterone, estradiol, and relative gonad weight. Miramichi CYP1A mRNA levels were higher than Kouchibouguac in the fall but lower in the spring sample. The CYP1A mRNA-sex steroid relationship observed in this study will facilitate meaningful interpretation of data collected during the full 4-year study.« less