RRC ID 21142
Author Kera K, Takahashi S, Sutoh T, Koyama T, Nakayama T.
Title Identification and characterization of a cis,trans-mixed heptaprenyl diphosphate synthase from Arabidopsis thaliana.
Journal FEBS J
Abstract In eukaryotes, dolichols (C(70-120)) play indispensable roles as glycosyl carrier lipids in the biosynthesis of glycoproteins on endoplasmic reticulum. In addition to dolichols, seed plants have other types of Z,E-mixed polyisoprenoids termed ficaprenol (tri-trans,poly-cis-polyprenol, C(45-75)) and betulaprenol (di-trans,poly-cis-polyprenol, C(30-45) and C(≥70)) in abundance. However, the physiological significance of these polyprenols has not been elucidated because of limited information regarding cis-prenyltransferases (cPTs) which catalyze the formation of the structural backbone of Z,E-mixed polyisoprenoids. In the comprehensive identification and characterization of cPT homologues from Arabidopsis thaliana, AtHEPS was identified as a novel cis,trans-mixed heptaprenyl diphosphate synthase. AtHEPS heterologously expressed in Escherichia coli catalyzed the formation of C(35) polyisoprenoid as a major product, independent of the chain lengths of all-trans allylic primer substrates. Kinetic analyses revealed that farnesyl diphosphate was the most favorable for AtHEPS among the allylic substrates tested suggesting that AtHEPS was responsible for the formation of C(35) betulaprenol. AtHEPS partially suppressed the phenotypes of a yeast cPT mutant deficient in the biosynthesis of dolichols. Moreover, in A. thaliana cells, subcellular localization of AtHEPS on the endoplasmic reticulum was shown by using green fluorescent protein fused proteins. However, a cold-stress-inducible expression of AtHEPS suggested that AtHEPS and its product might function in response to abiotic stresses rather than in cell maintenance as a glycosyl carrier lipid on the endoplasmic reticulum.
Volume 279(20)
Pages 3813-27
Published 2012-10-1
DOI 10.1111/j.1742-4658.2012.08742.x
PMID 22883514
MeSH Abscisic Acid / pharmacology Alkyl and Aryl Transferases / classification Alkyl and Aryl Transferases / genetics Alkyl and Aryl Transferases / metabolism* Arabidopsis / cytology Arabidopsis / enzymology* Arabidopsis / genetics Arabidopsis Proteins / genetics Arabidopsis Proteins / metabolism* Biocatalysis Blotting, Western Cations, Divalent / pharmacology Cells, Cultured Cold Temperature Endoplasmic Reticulum / enzymology Gene Expression Regulation, Enzymologic / drug effects Gene Expression Regulation, Plant / drug effects Genetic Complementation Test Green Fluorescent Proteins / genetics Green Fluorescent Proteins / metabolism Kinetics Microscopy, Confocal Mutation Phylogeny Plant Growth Regulators / pharmacology Polyisoprenyl Phosphates / metabolism Recombinant Proteins / metabolism Reverse Transcriptase Polymerase Chain Reaction Saccharomyces cerevisiae / enzymology Saccharomyces cerevisiae / genetics Saccharomyces cerevisiae / growth & development Sesquiterpenes / metabolism Substrate Specificity Transferases / classification Transferases / genetics Transferases / metabolism*
IF 4.392
Times Cited 23
Arabidopsis / Cultured plant cells, genes rpc00008 pda07581