IDI2, a Second Isopentenyl Diphosphate Isomerase in Mammals

We recently described the identification of a novel isopentenyl diphosphate isomerase, IDI2 in humans and mice. Our current data indicate that, in humans, IDI2 is expressed only in skeletal muscle. Expression constructs of human IDI2 in Saccharomyces cerevisiae can complement isomerase function in a...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2007-03, Vol.282 (9), p.6668-6676
Main Authors: Clizbe, Daun B., Owens, Michelle L., Masuda, Kimberly R., Shackelford, Janis E., Krisans, Skaidrite K.
Format: Article
Language:English
Subjects:
Animals
Carbon-Carbon Double Bond Isomerases - genetics
Carbon-Carbon Double Bond Isomerases - metabolism
Catalysis
Cloning, Molecular
Genetic Complementation Test
Hemiterpenes
Humans
Isoenzymes
Isomerism
Kinetics
Mice
Peroxisomes - enzymology
PPAR alpha
Saccharomyces cerevisiae
Saccharomyces cerevisiae - genetics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We recently described the identification of a novel isopentenyl diphosphate isomerase, IDI2 in humans and mice. Our current data indicate that, in humans, IDI2 is expressed only in skeletal muscle. Expression constructs of human IDI2 in Saccharomyces cerevisiae can complement isomerase function in an idi1-deficient yeast strain. Furthermore, IDI2 has the ability to catalyze the isomerization of [14C]IPP to [14C]DMAPP. Enzyme kinetic analysis of partially purified IDI2 demonstrate the novel isozyme has a maximal relative specific activity of 1.2 × 10-1 ± 0.3 μmol min-1 mg-1 at pH 8.0 with a KIPPm value of 22.8 μm IPP. Both isozymes, IDI1 and IDI2 are localized to the peroxisome by a PTS1-dependent pathway. Finally, our data suggest that IDI2 is regulated independently from IDI1, by a mechanism that may involve PPARα.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M610922200