Characterization of cDNA and genomic clones encoding 3-hydroxy-3-methylglutaryl-coenzyme A reductase from Hevea brasiliensis

Abstract

Hevea brasiliensis is the major producer of natural rubber which is cis-1,4-polyisoprene. The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) is involved in the biosynthesis of rubber and other plant products. We have used a hamster HMGR cDNA clone as a heterologous hybridization probe to isolate and characterize cDNA and genomic clones of HMGR from H. brasiliensis. Sequence analysis revealed that these clones fall into two different classes, HMGR1 and HMGR2. Comparison of the two classes shows 86% nucleotide sequence homology and 95% amino acid homology. The carboxy-termini of Hevea HMGRs are highly homologous to those of hamster, yeast and Arabidopsis HMGR. The amino-terminus of Hevea HMGR contains two potential membrane-spanning domains as in Arabidopsis HMGR while seven such domains are found in the HMGRs of other organisms. The apparent molecular mass of Hevea HMGR was estimated in western blot analysis to be 59 kDa. Northern blot analysis indicated that the HMGR1 transcript of 2.4 kb is more highly-expressed in laticifer than in leaf. Genomic Southern analysis using 3'-end cDNA probes indicates the presence of at least two HMGR genes in Hevea.

Cloning and Characterization of Mevalonate Pathway Genes in a Natural Rubber Producing Plant,Hevea brasiliensis

“…X54658), and HMGR3 (accession no. M74800) have been reported, [6][7][8] but the sequence information for HMGR2 was incomplete, so it was not dealth with in the current study. HMGR showed 77% identity to HMGR3.…”

“…[1][2][3] Molecular biology studies have recently reported the sequences of the HMGS genes 4,5) and HMGR genes 6,7) and the sequences of the genes of the entire MVA pathway 8) in H. brasiliensis. In addition, large-scale transcriptome analyses of the latex of H. brasiliensis have been performed, 9,10) but molecular biological characterization of the MVA pathway as a whole has been inadequate.…”

Isolation and Characterization of cDNAs Encoding Wheat 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase

“…cDNAs and genomic HMGR clones have been isolated from Drosophila (Gertler et al, 1988), yeast (Basson et al, 1988), sea urchin (Woodward et al, 1988), hamster (Chin et al, 1984), and human (Luskey and Stevens, 1985). Recently, with the use of hamster and yeast probes plant HMGR cDNAs and genomic clones have been isolated from Arabidopsis (Caelles et al, 1989;Leamed and Fink, 1989), tomato (Narita and Gruissem, 1989;Narita et al, 1991), and Hevea (Chye et al, 1991). Sequence similarities among HMGR genes of expression of wheat (Triticum aestivum) HMGR genes because of the potential uses of their molecular components.…”

Sequence comparison of a segment of the gene for 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase in zygomycetes

“…MmHMGl clones could be isolated from both M. mucedo strains, whereas MmHMG2 was obtained exclusively from CBS 109. 16 Interestingly, the DNA of A. glauca gives two additional PCR bands (Fig. lA, lane 2).…”