P450 Oxidoreductase Deficiency: loss of activity caused by protein instability from a novel L374H mutation.

Parween, Shaheena; Boulez, Florence Roucher; Flück Pandey, Christa Emma; Lienhardt-Roussie, Anne; Mallet, Delphine; Morel, Yves; Pandey, Amit Vikram (2016). P450 Oxidoreductase Deficiency: loss of activity caused by protein instability from a novel L374H mutation. The Journal of clinical endocrinology and metabolism, 101(12), jc.2016-1928. The Endocrine Society 10.1210/jc.2016-1928

[img] Text
2016_JCEM2.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (2MB) | Request a copy

CONTEXT P450 oxidoreductase (POR) is required for the activities of steroid metabolizing cytochrome P450 enzymes in the endoplasmic reticulum. P450 oxidoreductase deficiency (PORD) is a form of congenital adrenal hyperplasia. OBJECTIVE AND AIM Enzymatic and structural analysis of a novel L374H POR mutation from a patient with 46, XX disorder of sexual development. Design, setting, patient and intervention: 46,XX girl with non-consanguineous Turkish parents. Virilized external genitalia at birth; uterus and ovaries present, no sign of Antley-Bixler syndrome. Initial diagnosis of CYP21A2 deficiency, no mutations in CYP21A2 but found POR mutations. Functional testing done after producing recombinant POR proteins for analyzing enzymatic and structural properties. MAIN OUTCOME Novel mutations causing severe loss of POR activities for metabolism of steroids and small molecules. RESULTS The L374H reduced activities by 80% in cytochrome c, 97% in MTT and 86% in ferricyanide reduction assays. The catalytic efficiency of 17 α-hydroxylation of progesterone and 17, 20-lyase reaction of 17-OH pregnenolone was decreased by 87% and 90 %, 21-hydroxylation of progesterone was decreased by 96 % and androstenedione aromatization was decreased by 90%. Analysis of mutant structure by molecular dynamic simulations revealed structure instability. Flavin release and fast proteolysis assays showed that the L374H mutant is less stable than WT POR, confirming bioinformatics prediction. CONCLUSIONS This is the first report of a mutation causing PORD by affecting protein stability which causes severe reduction in POR activities. Detailed characterization of individual mutations in POR is required for understanding novel molecular mechanisms causing PORD.

Item Type:

Journal Article (Further Contribution)

Division/Institute:

04 Faculty of Medicine > Department of Gynaecology, Paediatrics and Endocrinology (DFKE)
04 Faculty of Medicine > Department of Gynaecology, Paediatrics and Endocrinology (DFKE) > Clinic of Paediatric Medicine
04 Faculty of Medicine > Faculty Institutions > Teaching Staff, Faculty of Medicine
04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > Unit Childrens Hospital > Forschungsgruppe Endokrinologie / Diabetologie / Metabolik (Pädiatrie)

UniBE Contributor:

Parween, Shaheena; Flück Pandey, Christa Emma and Pandey, Amit Vikram

Subjects:

600 Technology > 610 Medicine & health
500 Science > 570 Life sciences; biology

ISSN:

1945-7197

Publisher:

The Endocrine Society

Funders:

[4] Swiss National Science Foundation

Projects:

[102] Pathogenesis of disorders caused by human P450 oxidoreductase mutations Official URL

Language:

English

Submitter:

Amit Vikram Pandey

Date Deposited:

22 Sep 2016 10:11

Last Modified:

22 Oct 2019 18:55

Publisher DOI:

10.1210/jc.2016-1928

PubMed ID:

27603900

BORIS DOI:

10.7892/boris.88459

URI:

https://boris.unibe.ch/id/eprint/88459

Actions (login required)

Edit item Edit item
Provide Feedback