TY - JOUR
T1 - Identification and characterization of a cis,trans-mixed heptaprenyl diphosphate synthase from Arabidopsis thaliana
AU - Kera, Kota
AU - Takahashi, Seiji
AU - Sutoh, Tsuyoshi
AU - Koyama, Tanetoshi
AU - Nakayama, Toru
PY - 2012/10
Y1 - 2012/10
N2 - In eukaryotes, dolichols (C70-120) 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 C35 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 C35 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.
AB - In eukaryotes, dolichols (C70-120) 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 C35 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 C35 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.
KW - Arabidopsis thaliana
KW - cis-prenyltransferase
KW - dolichol
KW - isoprenoid biosynthesis
KW - polyprenol
UR - http://www.scopus.com/inward/record.url?scp=84867100495&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84867100495&partnerID=8YFLogxK
U2 - 10.1111/j.1742-4658.2012.08742.x
DO - 10.1111/j.1742-4658.2012.08742.x
M3 - Article
C2 - 22883514
AN - SCOPUS:84867100495
VL - 279
SP - 3813
EP - 3827
JO - FEBS Journal
JF - FEBS Journal
SN - 1742-464X
IS - 20
ER -