Molecular cloning of a novel pathogen-inducible cDNA encoding a putative acyl-CoA synthetase from Capsicum annuum L.
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.
Lee
S J
SJ
School of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Suwon, Korea.
Suh
M C
MC
Kim
S
S
Kwon
J K
JK
Kim
M
M
Paek
K H
KH
Choi
D
D
Kim
B D
BD
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D002212:Capsicum / Q000201:enzymology / Q000235:genetics*; D003001:Cloning, Molecular; D003066:Coenzyme A Ligases / Q000235:genetics*; D018076:DNA, Complementary; D008969:Molecular Sequence Data; D010802:Phylogeny; D010946:Plants, Medicinal; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D003066:Coenzyme A Ligases