title: Different functions and expression profiles of curcin and curcin-L in Jatropha curcas L.
abstract: To date, two types of ribosome-inactivating proteins (RIPs) have been found in Jatropha curcas. One is curcin, which has been isolated from the endosperm, and the other is curcin-L, which is expressed in leaves upon stress treatment. Phylogenetic analysis of the predicted amino acid sequences of the RIPs in plants revealed that these belong to a major subfamily and are close to trichosanthin (TCS). Studies on the mRNA and protein levels showed that both curcin and curcin-L have an organ-specific expression pattern. Curcin is only expressed and accumulated in the endosperm; its expression begins in the globular embryo period and peaks during the mature embryo period. In contrast, curcin-L is only expressed in the leaves, but its expression is induced by certain conditions such as treatment with phytohormones or polyethylene glycol, exposure to high and low temperatures, and fungal infection. Analysis of the 5' flanking regions of curcin and curcin-L revealed that the 5' flanking region of curcin-L has three major inserted fragments, which are not present in the corresponding region of curcin. Comparison of characteristic cis-elements suggests the presence of several motifs that are involved in the endosperm-specific expression in the 5' flanking region of curcin, while in curcin-L some stress- and defense-responsive motifs are found to be mainly located in the three inserted fragments. Comparison of the antifungal activity of the two RIPs showed that the one of curcin-L is higher than that of curcin. Differences in the expression and activity of curcin and curcin-L suggest that these two RIPs have different functions.
authors.affiliation: College of Life Sciences, Sichuan University, Chengdu 610064, P.R. China. qin_ever@hotmail.com
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Qin
authors.forename: Caixia
authors.initials: C
authors.lastname: Shao
authors.forename: Pei
authors.initials: P
authors.lastname: Hou
authors.forename: Jihai
authors.initials: J
authors.lastname: Gao
authors.forename: Ningfei
authors.initials: N
authors.lastname: Lei
authors.forename: Luding
authors.initials: L
authors.lastname: Jiang
authors.forename: Shengliang
authors.initials: S
authors.lastname: Ye
authors.forename: Chunbao
authors.initials: C
authors.lastname: Gou
authors.forename: Shaoyin
authors.initials: S
authors.lastname: Luo
authors.forename: Xiaojiang
authors.initials: X
authors.lastname: Zheng
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Gu
authors.forename: Xihong
authors.initials: X
authors.lastname: Zhu
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Fang
authors.initials: F
authors.lastname: Chen
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D000935:Antifungal Agents / Q000494:pharmacology; D017931:DNA Primers; D018744:DNA, Plant / Q000235:genetics; D056625:Endosperm / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D031286:Jatropha / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000378:metabolism; D054789:Ribosome Inactivating Proteins, Type 1 / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D020121:5' Untranslated Regions; D000935:Antifungal Agents; D017931:DNA Primers; D018744:DNA, Plant; D011994:Recombinant Proteins; D054789:Ribosome Inactivating Proteins, Type 1; C515388:curcin protein, Jatropha curcas