Molecular cloning of a novel pathogen-inducible cDNA encoding a putative acyl-CoA synthetase from Capsicum annuum L

• Published in: Plant molecular biology 2001-08, Vol.46 (6), p.661-671
• Main Authors: Lee, Sang Jik, Suh, Mi-Chung, Kim, Shinje, Kwon, Jin-Kyung, Kim, Minwoo, Paek, Kyung-Hee, Choi, Doil, Kim, Byung-Dong
• Format: Article
• Language: English
• Subjects: acyl coenzyme A; acyl-CoA synthetase; Amino Acid Sequence; amino acid sequences; Amino acids; Bacteria; Base Sequence; biolistics; Blotting, Southern; Capsicum - enzymology; Capsicum - genetics; Capsicum annuum; CaSIG4 gene; cDNA libraries; clones; Cloning; Cloning, Molecular; Coenzyme A Ligases - genetics; complementary DNA; DNA, Complementary; gene fusion; genes; leaves; long-chain-fatty-acid-CoA ligase; messenger RNA; Molecular Sequence Data; molecular weight; onions; open reading frames; pepper; Phylogeny; Plant tissues; Plants, Medicinal; plasma membrane; Polymerase Chain Reaction; Proteins; regulatory sequences; salicyclic acid; salicylic acid; sequence homology; Sequence Homology, Amino Acid; tissues; Xanthomonas campestris; Xanthomonas vesicatoria
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1023/A:1011677028605

By means of differential display, a pool of salicylic acid (SA)-induced mRNAs were identified and subsequently their cDNAs were isolated from a cDNA library prepared from SA-induced leaf tissues of hot pepper. One of these cDNA clones, designated CaSIG4, was 1900 bp and contained an open reading frame encoding 523 amino acids with a calculated molecular mass of 56.3 kDa. The predicted amino acid sequence of CaSIG4 showed high sequence similarity to the AMP-binding protein family of both prokaryotic and eukaryotic acyl-CoA synthetases. CaSIG4 transcripts accumulated rapidly after SA treatment and in response to both incompatible and compatible interactions with Xanthomonas campestris pv. vesicatoria race 1. To investigate the cis-acting elements mediating CaSIG4 expression, the CaSIG4 5′-flanking region was isolated by inverse PCR. Database searches indicated that a potential cis-regulatory element is almost identical to the consensus core sequences ACC(A/T)ACC(A/C) which are conserved among promoters of other phenylpropanoid biosynthetic genes. The subcellular localization of the CaSIG4 protein was studied by using a soluble modified GFP gene fusion delivered into epidermal cells of onion by biolistic bombardment. The CaSIG4-smGFP fusion protein was localized to the plasma membrane. Taken together, CaSIG4 encoding a putative acyl-CoA synthetase could function as a plasma membrane-bound protein with a role in signaling in plant defense.