Cloning and functional characterization of an acyl-acyl carrier protein thioesterase (JcFATB1) from Jatropha curcas.
A full-length cDNA of an acyl-acyl carrier protein (ACP) thioesterase (TE) (EC 3.1.2.14), named JcFATB1, was isolated from the woody oil plant Jatropha curcas L. The deduced amino acid sequence of the cDNA shares about 78% identity with FATB TEs, but only about 33% identity with FATA TEs from other plants. The deduced sequence also contains two essential residues (H(317) and C(352)) for TE catalytic activity and a putative chloroplast transit peptide at the N-terminal. Southern blot analysis revealed that a single copy of JcFATB1 is present in the J. curcas genome, and semi-quantitative PCR analysis showed that JcFATB1 was expressed in all tissues that were examined, most strongly in seeds, in which its expression peaked in late developmental stages. Seed-specific overexpression of the JcFATB1 cDNA in Arabidopsis resulted in increased levels of saturated fatty acids, especially palmitate, and in reduced levels of unsaturated fatty acids. The findings suggest that JcFATB1 from this woody oil plant can function as a saturated acyl-ACP TE and could potentially modify the seed oil of J. curcas to increase its levels of palmitate.
Wu
Ping-Zhi
PZ
Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Li
Jun
J
Wei
Qian
Q
Zeng
Ling
L
Chen
Ya-Ping
YP
Li
Mei-Ru
MR
Jiang
Hua-Wu
HW
Wu
Guo-Jiang
GJ
D000595:Amino Acid Sequence; D031286:Jatropha / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013869:Thiolester Hydrolases / Q000145:classification / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*
D013869:Thiolester Hydrolases; C018748:oleoyl-(acyl-carrier-protein) hydrolase