Human NADPH-cytochrome P450 oxidoreductase (POR) gene mutations are associated with severe skeletal deformities and disordered steroidogenesis. The human POR mutation A287P presents with disordered sexual development and skeletal malformations. Difficult recombinant expression and purification of this POR mutant suggested that the protein was less stable than WT. The activities of cytochrome P450 17A1, 19A1, and 21A2, critical in steroidogenesis, were similar using our purified, full-length, unmodified A287P or WT POR, as were those of several xenobiotic-metabolizing cytochromes P450, indicating that the A287P protein is functionally competent in vitro, despite its functionally deficient phenotypic behavior in vivo Differential scanning calorimetry and limited trypsinolysis studies revealed a relatively unstable A287P compared with WT protein, leading to the hypothesis that the syndrome observed in vivo results from altered POR protein stability. The crystal structures of the soluble domains of WT and A287P reveal only subtle differences between them, but these differences are consistent with the differential scanning calorimetry results as well as the differential susceptibility of A287P and WT observed with trypsinolysis. The relative in vivo stabilities of WT and A287P proteins were also examined in an osteoblast cell line by treatment with cycloheximide, a protein synthesis inhibitor, showing that the level of A287P protein post-inhibition is lower than WT and suggesting that A287P may be degraded at a higher rate. Current studies demonstrate that, unlike previously described mutations, A287P causes POR deficiency disorder due to conformational instability leading to proteolytic susceptibility in vivo, rather than through an inherent flavin-binding defect.

• Klíčová slova
• POR deficiency, cytochrome P450, cytochrome P450 oxidoreductase, diflavin oxidoreductase, flavoprotein, membrane protein, protein crystallization, protein stability, reductase,
• MeSH
• fenotyp Antley-Bixlerova syndromu * enzymologie   genetika   MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• missense mutace * MeSH
• stabilita enzymů genetika   MeSH
• substituce aminokyselin MeSH
• systém (enzymů) cytochromů P-450 chemie   genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• POR protein, human MeSH Prohlížeč
• systém (enzymů) cytochromů P-450 MeSH

AIM: Estimating polymorphic allele frequencies of the NADPH-CYP450 oxidoreductase (POR) gene in a Czech Slavic population. METHODS: The POR gene was analyzed in 322 individuals from a control cohort by sequencing and high resolution melting analysis. RESULTS: We identified seven unreported SNP genetic variations, including two SNPs in the 5' flanking region (g.4965C>T and g.4994G>T), one intronic variant (c.1899-20C>T), one synonymous SNP (p.20Ala=) and three nonsynonymous SNPs (p.Thr29Ser, p.Pro384Leu and p.Thr529Met). The p.Pro384Leu variant exhibited reduced enzymatic activities compared with wild-type. CONCLUSION: New POR variant identification indicates the number of uncommon variants might be specific for each subpopulation being investigated, particularly germane to the singular role that POR plays in providing reducing equivalents to all CYP450s in the endoplasmic reticulum. Original submitted 15 September 2014; Revision submitted 17 November 2014.

• Klíčová slova
• CYP, Czech Slavic population, NADPH-cytochrome, P450 oxidoreductase, P450 reductase, POR, allele frequencies, haplotype, pharmacogenetics,
• MeSH
• DNA genetika   MeSH
• dospělí MeSH
• frekvence genu MeSH
• genetická variace MeSH
• haplotypy MeSH
• jednonukleotidový polymorfismus * MeSH
• kinetika MeSH
• kohortové studie MeSH
• konformace proteinů MeSH
• lidé MeSH
• missense mutace MeSH
• molekulární modely MeSH
• novorozenec MeSH
• sekvence nukleotidů MeSH
• substituce aminokyselin MeSH
• systém (enzymů) cytochromů P-450 chemie   genetika   metabolismus   MeSH
• vazebná nerovnováha MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• DNA MeSH
• POR protein, human MeSH Prohlížeč
• systém (enzymů) cytochromů P-450 MeSH

There is growing evidence that some members of cytochrome P450 enzymes contribute to regulation of normal prenatal development. CYP epoxygenases (CYP2C and CYP2J subfamilies) convert arachidonic acid into four regioisomeric epoxyeicosatrienoic acids (EETs), biologically active molecules involved in mitogenesis and cell signaling. Almost nothing is known about localization of their expression in tissues during human prenatal development. The spatio-temporal expression pattern of CYP2C8, CYP2C9, CYP2C19 and CYP2J2 in human embryonic/fetal intestines, liver, and kidney was investigated by immunohistochemical method. CYP epoxygenases are expressed already in early stages of development in these embryonic/fetal tissues (as early as 7th week of IUD in the intestines, 5th week of IUD in the liver, and 6th week of IUD in the kidney). In kidney, CYP epoxygenases are expressed in the metanephrogenic blastema (but not in the uninduced mesenchyme) and in the tubular system. In the intestines, diverse CYP epoxygenases distribution along crypt-villus axis could suggest role in cell differentiation. Moreover, we detected higher CYP2J2 level in these organs than in adult tissue samples.

• Klíčová slova
• CYP epoxygenases, human embryos, intestine, kidney, liver,
• MeSH
• časové faktory MeSH
• cytochrom P-450 CYP2J2 MeSH
• cytochrom P450 CYP2C8 genetika   MeSH
• embryo savčí enzymologie   MeSH
• imunohistochemie MeSH
• játra embryologie   enzymologie   MeSH
• ledviny embryologie   enzymologie   MeSH
• lidé embryologie   MeSH
• střeva embryologie   enzymologie   MeSH
• systém (enzymů) cytochromů P-450 genetika   metabolismus   MeSH
• vývojová regulace genové exprese * MeSH
• Check Tag
• lidé embryologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• CYP2J2 protein, human MeSH Prohlížeč
• cytochrom P-450 CYP2J2 MeSH
• cytochrom P450 CYP2C8 MeSH
• systém (enzymů) cytochromů P-450 MeSH

BACKGROUND: The enzyme NADPH-P450 oxidoreductase (POR) is the main electron donor to all microsomal CYPs. The possible contribution of common POR variants to inter- and intra-individual variability in drug metabolism is of great pharmacogenetic interest. AIM: To search for POR polymorphic alleles and estimate their frequencies in a Jewish population. MATERIALS & METHODS: We analyzed the POR gene in 301 Ashkenazi and Moroccan Jews. RESULTS: A total of 30 POR SNPs were identified, nine in the noncoding regions and 21 in the protein-coding regions (ten synonymous, 11 missense). Six of these missense variants are previously undescribed (S102P, V164M, V191M, D344N, E398A and D648N). CONCLUSION: The data collected in this study on missense POR SNPs, interpreted in light of the crystallographic structure of human POR, indicate that some POR missense variants may be potential biomarkers for future POR pharmacogenetic screening.

• MeSH
• farmakogenetika MeSH
• frekvence genu MeSH
• genetické markery MeSH
• haplotypy MeSH
• jednonukleotidový polymorfismus * MeSH
• lidé MeSH
• missense mutace * MeSH
• molekulární modely MeSH
• NADPH-cytochrom c-reduktasa chemie   genetika   MeSH
• sekvenční analýza DNA MeSH
• vazebná nerovnováha MeSH
• Židé genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Geografické názvy
• Izrael epidemiologie   MeSH
• Maroko etnologie   MeSH
• Názvy látek
• genetické markery MeSH
• NADPH-cytochrom c-reduktasa MeSH