Aldo-Keto Reductase 1B15 (AKR1B15): A mitochondrial human aldo-keto reductase with activity toward steroids and 3-keto-acyl-CoA conjugates.
J. Biol. Chem. 290, 6531-6545 (2015)
Alto-keto reductases (AKRs) comprise a superfamily of proteins involved in the reduction and oxidation of biogenic and xenobiotic carbonyls. In humans, at least 15 AKR superfamily members have been identified so far. One of these is a newly identified gene locus, AKR1B15, which clusters on chromosome 7 with the other human AKR1B subfamily members (i.e. AKR1B1 and AKR1B10). We show that alternative splicing of the AKR1B15 gene transcript gives rise to two protein isoforms with different N termini: AKR1B15.1 is a 316-amino acid protein with 91% amino acid identity to AKR1B10; AKR1B15.2 has a prolonged N terminus and consists of 344 amino acid residues. The two gene products differ in their expression level, subcellular localization, and activity. In contrast with other AKR enzymes, which are mostly cytosolic, AKR1B15.1 co-localizes with the mitochondria. Kinetic studies show that AKR1B15.1 is predominantly a reductive enzyme that catalyzes the reduction of androgens and estrogens with high positional selectivity (17β-hydroxysteroid dehydrogenase activity) as well as 3-ketoacyl-CoA conjugates and exhibits strong cofactor selectivity toward NADP(H). In accordance with its substrate spectrum, the enzyme is expressed at the highest levels in steroid-sensitive tissues, namely placenta, testis, and adipose tissue. Placental and adipose expression could be reproduced in the BeWo and SGBS cell lines, respectively. In contrast, AKR1B15.2 localizes to the cytosol and displays no enzymatic activity with the substrates tested. Collectively, these results demonstrate the existence of a novel catalytically active AKR, which is associated with mitochondria and expressed mainly in steroid-sensitive tissues.
Impact Factor
Scopus SNIP
Web of Science
Times Cited
Scopus
Cited By
Altmetric
Publication type
Article: Journal article
Document type
Scientific Article
Thesis type
Editors
Keywords
3-keto-acyl-CoA; Aldo-Keto Reductase; alternative splicing; enzyme kinetics; gene expression; mitochondria; oxidation-reduction (redox); reductase; steroid; Chain L-3-hydroxyacyl-coa Dehydrogenase; Gamma-hydroxybutyrate; Delta(4)-3-oxosteroid 5-beta-reductase; 3-hydroxyacyl-coa Dehydrogenase; Subcellular-localization; Diabetic Complications; Aldehyde Reductase; Potassium Channels; Insulin-secretion; Active-site
Keywords plus
Language
english
Publication Year
2015
Prepublished in Year
HGF-reported in Year
2015
ISSN (print) / ISBN
0021-9258
e-ISSN
1083-351X
ISBN
Book Volume Title
Conference Title
Conference Date
Conference Location
Proceedings Title
Quellenangaben
Volume: 290,
Issue: 10,
Pages: 6531-6545
Article Number: ,
Supplement: ,
Series
Publisher
American Society for Biochemistry and Molecular Biology
Publishing Place
Bethesda
Day of Oral Examination
0000-00-00
Advisor
Referee
Examiner
Topic
University
University place
Faculty
Publication date
0000-00-00
Application date
0000-00-00
Patent owner
Further owners
Application country
Patent priority
Reviewing status
Peer reviewed
POF-Topic(s)
30201 - Metabolic Health
30504 - Mechanisms of Genetic and Environmental Influences on Health and Disease
90000 - German Center for Diabetes Research
Research field(s)
Genetics and Epidemiology
Immune Response and Infection
PSP Element(s)
G-505600-001
G-501793-001
G-501900-061
Grants
Copyright
Erfassungsdatum
2015-03-26