Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. Two kinds of intermediates, sitosterol and campesterol, play a crucial role ...Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. Two kinds of intermediates, sitosterol and campesterol, play a crucial role in cell elongation, cellulose biosynthesis, and accumulation. To illuminate the effects of sitosterol and campesterol on the development of cotton （Gossypiurn hirsuturm L.） fibers through screening cotton fiber EST database and contigging the candidate ESTs, two key genes GhSMT2-1 and GhSMT2-2 controlling the sitosterol biosynthesis were cloned from developing fibers of upland cotton cv. Xuzhou 142. The full length of GhSMT2-1 was 1,151 bp, including an 8 bp 5＇-untranslated region （UTR）, a 1,086 bp open reading frame （ORF）, and a 57 bp 3＇-UTR. GhSMT2-1 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The full length of GhSMT2-2 was 1,166 bp, including an 18 bp 5＇-UTR, a 1,086 bp ORF, and a 62 bp 3＇-UTR. GhSMT2-2 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The two deduced amino acid sequences had high homology with the SMT2 from Arabidopsis thaliana and Nicotiana tabacurn. Furthermore, the typical conserved structures characterized by the sterol C-24 methyltransferase, such as region I （LDVGCGVGGPMRAI）, region II （IEATCHAP）, and region III （YEWGWGQSFHF）, were present in both deduced proteins. Southern blotting analysis indicated that GhSMT2-1 or GhSMT2-2 was a single copy in upland cotton genome. Quantitative real-time RT-PCR analysis revealed that the highest expression levels of both genes were detected in 10 DPA （day post anthesis） fibers, while the lowest levels were observed in cotyledon and leaves. The expression level of GhSMT2-1 was 10 times higher than that of GhSMT2-2 in all the organs and tissues detected. These results indicate that the homologue of sterol C-24 methyltransferase gene was cloned from upland cotton and both GhSMT2 genes play a crucial role in fiber elongation. The role of GhSMT2-1 may be more important than that of GhSMT2-2.展开更多
Leishmaniasis is a vector-borne parasitic neglected tropical disease caused by a group of about 30 different species of the genus Leishmania.It is transmitted by the bite of female phlebotomies sand fly.Three main cli...Leishmaniasis is a vector-borne parasitic neglected tropical disease caused by a group of about 30 different species of the genus Leishmania.It is transmitted by the bite of female phlebotomies sand fly.Three main clinical manifestations of leishmaniasis include cutaneous,visceral,and mucocutaneous leishmaniasis.Visceral leishmaniasis(VL)caused by Leishmania donovani,is an infection of reticuloendothelial system and fatal if untreated.Cholesterol,a sterol that is prominent in the mammalian cell membranes whereas stigmasterol and ergosterol are more prevalent in plants,yeast,and protozoa,respectively.Ergosterols which is absent in human being,is an important constituent of parasite membrane.Sterol C-24 reductase(LdSR)enzyme catalyzes the final step in the ergosterol biosynthesis pathway.The inhibition of biosynthesis of ergosterol may lead to decreased cell viability and growth.Here,we performed the molecular docking-based virtual screening of a library of natural ligands against LdSR to identify a potential inhibitor to fight leishmaniasis.Capsaicin,prenyletin,flavan-3-ol,resveratrol,and gingerol showed the top binding affinity towards LdSR.Based upon ADME properties and bioactivity score,gingerol showed the best lead-likeness and drug-likeness properties.Hence,we further annotated its leishmanicidal properties.We found that gingerol inhibited the growth and proliferation of promastigotes as well as intra-macrophagic amastigotes.Gingerol exerted its antileishmanial action through the induction of reactive oxygen species(ROS)in concentration-dependent manner.Gingerol induced ROS led to apoptosis.Overall,this study described that gingerol would act as possible inhibitor to LdSR.展开更多
基金supported by the National Natural Science Foundation of China(No.30370904 and 30671258)the National High Technology Research and Development Program(863 Project)of China(No.2006AA10Z121)the Program for New Century Excellent Talents in University(No.NCET-07-0712).
文摘Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. Two kinds of intermediates, sitosterol and campesterol, play a crucial role in cell elongation, cellulose biosynthesis, and accumulation. To illuminate the effects of sitosterol and campesterol on the development of cotton （Gossypiurn hirsuturm L.） fibers through screening cotton fiber EST database and contigging the candidate ESTs, two key genes GhSMT2-1 and GhSMT2-2 controlling the sitosterol biosynthesis were cloned from developing fibers of upland cotton cv. Xuzhou 142. The full length of GhSMT2-1 was 1,151 bp, including an 8 bp 5＇-untranslated region （UTR）, a 1,086 bp open reading frame （ORF）, and a 57 bp 3＇-UTR. GhSMT2-1 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The full length of GhSMT2-2 was 1,166 bp, including an 18 bp 5＇-UTR, a 1,086 bp ORF, and a 62 bp 3＇-UTR. GhSMT2-2 gene encoded a polypeptide of 361 amino acid residues with a predicted molecular mass of 40 kDa. The two deduced amino acid sequences had high homology with the SMT2 from Arabidopsis thaliana and Nicotiana tabacurn. Furthermore, the typical conserved structures characterized by the sterol C-24 methyltransferase, such as region I （LDVGCGVGGPMRAI）, region II （IEATCHAP）, and region III （YEWGWGQSFHF）, were present in both deduced proteins. Southern blotting analysis indicated that GhSMT2-1 or GhSMT2-2 was a single copy in upland cotton genome. Quantitative real-time RT-PCR analysis revealed that the highest expression levels of both genes were detected in 10 DPA （day post anthesis） fibers, while the lowest levels were observed in cotyledon and leaves. The expression level of GhSMT2-1 was 10 times higher than that of GhSMT2-2 in all the organs and tissues detected. These results indicate that the homologue of sterol C-24 methyltransferase gene was cloned from upland cotton and both GhSMT2 genes play a crucial role in fiber elongation. The role of GhSMT2-1 may be more important than that of GhSMT2-2.
基金Deanship of Scientific Research at Majmaah University,Al Majmaah,11952,Saudi Arabia for supporting this work under the Group Project No.RGP-2019-31.
文摘Leishmaniasis is a vector-borne parasitic neglected tropical disease caused by a group of about 30 different species of the genus Leishmania.It is transmitted by the bite of female phlebotomies sand fly.Three main clinical manifestations of leishmaniasis include cutaneous,visceral,and mucocutaneous leishmaniasis.Visceral leishmaniasis(VL)caused by Leishmania donovani,is an infection of reticuloendothelial system and fatal if untreated.Cholesterol,a sterol that is prominent in the mammalian cell membranes whereas stigmasterol and ergosterol are more prevalent in plants,yeast,and protozoa,respectively.Ergosterols which is absent in human being,is an important constituent of parasite membrane.Sterol C-24 reductase(LdSR)enzyme catalyzes the final step in the ergosterol biosynthesis pathway.The inhibition of biosynthesis of ergosterol may lead to decreased cell viability and growth.Here,we performed the molecular docking-based virtual screening of a library of natural ligands against LdSR to identify a potential inhibitor to fight leishmaniasis.Capsaicin,prenyletin,flavan-3-ol,resveratrol,and gingerol showed the top binding affinity towards LdSR.Based upon ADME properties and bioactivity score,gingerol showed the best lead-likeness and drug-likeness properties.Hence,we further annotated its leishmanicidal properties.We found that gingerol inhibited the growth and proliferation of promastigotes as well as intra-macrophagic amastigotes.Gingerol exerted its antileishmanial action through the induction of reactive oxygen species(ROS)in concentration-dependent manner.Gingerol induced ROS led to apoptosis.Overall,this study described that gingerol would act as possible inhibitor to LdSR.
