Abstract
In higher plants, a variety of Z,E-mixed polyisoprenoids have been detected. However, the physiological roles of these compounds and the mechanism of chain length determination of cis-prenyltransferases (CPTs) which catalyze the formation of Z,E-mixed polyisoprenoids have been hardly elucidated. In order to understand the catalytic mechanisms of CPTs and the physiological roles of Z,E-mixed polyisoprenoids in higher plants, we cloned and characterized genes encoding CPTs in Arabidopsis thaliana.
In Arabidopsis genomic sequences, we found 9 genes that have high homology to CPT genes. By RT-PCR analysis, the expression pattern of the genes in various tissues was shown. According to the expression pattern, 7 cDNAs were isolated. Expression of these cDNAs in yeast rer2 strain, which is deficient in CPT activity, suppressed temperature-sensitive phenotype of the mutant. Moreover, the crude extract from these yeast strains harboring each cDNA from Arabidopsis showed actual prenyltransferase activity, catalyzing the formation of C50-C100 polyprenyl diphosphates.