A bifactorial endosperm box (EB), which contains an endosperm motif (EM) and a GCN4 motif, was found in rice Wx promoter. EB was found in 5′ upstream region of many seed storage protein genes accounting for these gen...A bifactorial endosperm box (EB), which contains an endosperm motif (EM) and a GCN4 motif, was found in rice Wx promoter. EB was found in 5′ upstream region of many seed storage protein genes accounting for these genes expression exclusive in endosperm among various cereals. Many reports demonstrated that the bZIP transcription activators isolated from wheat, barley and maize, etc. regulate the gene expression through binding to the GCN4 motif. In this research, we showed that GCN4 sequence could be recognized by nuclear proteins extracted from immature rice seeds. Furthermore, a rice bZIP protein, REB was isolated by using PCR method and REB fusion protein was expressed in E. coli. The results of gel shift analysis showed that REB could recognize and bind to the GCN4 motif in the Wx gene in addition to binding to the target sequence in the promoter of α-globulin.展开更多
The stability of GCN4 leucine zipper and its four mutants in guanidine hydrochloride was detected to verify the contributions of different a position amino acid residues in polypeptide sequences to the forming and sta...The stability of GCN4 leucine zipper and its four mutants in guanidine hydrochloride was detected to verify the contributions of different a position amino acid residues in polypeptide sequences to the forming and stability of parallel coiled coils. The changes of the circular dichroism spectra show that the displace- ment of the a position polar asparagine and the increase of asparagine in the GCN4 leucine zipper can reduce the α-helix content of the coiled coil structure. The mutants are less stable than the natural peptide in guanidine hydrochloride. The results show that the interaction between the polar asparagine contributes to the conformational stability of the coiled coil. Both the conformation and the number of polar residues in the coiled coil also affect the α-helix content and its resistance to the denaturant. The conclusions provide evidence describing the folding process of proteins including coiled coils in vivo.展开更多
GCN4是转录调节蛋白质二聚体,它可以在氨基酸饥饿的条件下控制酵母中histidine的生物合成。GCN4DNA结合区域是碱性区域/leucine拉链（bZIP）结构。GCN4的leucine拉链结构二聚成coiled-coil结构。GCN4的碱性区域结构光滑地插入AP-1DNA片...GCN4是转录调节蛋白质二聚体,它可以在氨基酸饥饿的条件下控制酵母中histidine的生物合成。GCN4DNA结合区域是碱性区域/leucine拉链（bZIP）结构。GCN4的leucine拉链结构二聚成coiled-coil结构。GCN4的碱性区域结构光滑地插入AP-1DNA片段的两边并与DNA主沟的对面结合。脚印跟踪（foot-printing）和one/two hybrid system protocols被用来研究GCN4和AP-1结合的定量构效关系。Max2-Jun是来自GCN4的变体之一。Max2-Jun的检测和表达的初步结果（Agro gel和HPLC）以及Max2-Jun和Ebox/XRE1的初步结合实验（foot-printing）表明Max2-Jun可能伴随一些不需要的组分。这些不需要的组分可能不能从需要的DNA片段/蛋白质中除去并且可能影响（正的/负的）需要的结合作用。进一步的GCN4蛋白质模型系统的设计正在进行中。展开更多
This article provides a brief overview describing how two key signaling pathways, namely the integrated stress response and the mammalian target of rapamycin complex 1, work together to facilitate cellular adaptation ...This article provides a brief overview describing how two key signaling pathways, namely the integrated stress response and the mammalian target of rapamycin complex 1, work together to facilitate cellular adaptation to dietary amino acid insufficiency. A deeper understanding of these mechanisms is leading to identification of novel targets which aid in disease treatments, improve stress recovery and increase health span through slowed aging and enhanced metabolic fitness.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39893320).
文摘A bifactorial endosperm box (EB), which contains an endosperm motif (EM) and a GCN4 motif, was found in rice Wx promoter. EB was found in 5′ upstream region of many seed storage protein genes accounting for these genes expression exclusive in endosperm among various cereals. Many reports demonstrated that the bZIP transcription activators isolated from wheat, barley and maize, etc. regulate the gene expression through binding to the GCN4 motif. In this research, we showed that GCN4 sequence could be recognized by nuclear proteins extracted from immature rice seeds. Furthermore, a rice bZIP protein, REB was isolated by using PCR method and REB fusion protein was expressed in E. coli. The results of gel shift analysis showed that REB could recognize and bind to the GCN4 motif in the Wx gene in addition to binding to the target sequence in the promoter of α-globulin.
基金Supported by the National Natural Science Foundation of China (No. 30170199) and the Basic Research Foundation of Tsinghua University (No. JC2003050)
文摘The stability of GCN4 leucine zipper and its four mutants in guanidine hydrochloride was detected to verify the contributions of different a position amino acid residues in polypeptide sequences to the forming and stability of parallel coiled coils. The changes of the circular dichroism spectra show that the displace- ment of the a position polar asparagine and the increase of asparagine in the GCN4 leucine zipper can reduce the α-helix content of the coiled coil structure. The mutants are less stable than the natural peptide in guanidine hydrochloride. The results show that the interaction between the polar asparagine contributes to the conformational stability of the coiled coil. Both the conformation and the number of polar residues in the coiled coil also affect the α-helix content and its resistance to the denaturant. The conclusions provide evidence describing the folding process of proteins including coiled coils in vivo.
文摘GCN4是转录调节蛋白质二聚体,它可以在氨基酸饥饿的条件下控制酵母中histidine的生物合成。GCN4DNA结合区域是碱性区域/leucine拉链（bZIP）结构。GCN4的leucine拉链结构二聚成coiled-coil结构。GCN4的碱性区域结构光滑地插入AP-1DNA片段的两边并与DNA主沟的对面结合。脚印跟踪（foot-printing）和one/two hybrid system protocols被用来研究GCN4和AP-1结合的定量构效关系。Max2-Jun是来自GCN4的变体之一。Max2-Jun的检测和表达的初步结果（Agro gel和HPLC）以及Max2-Jun和Ebox/XRE1的初步结合实验（foot-printing）表明Max2-Jun可能伴随一些不需要的组分。这些不需要的组分可能不能从需要的DNA片段/蛋白质中除去并且可能影响（正的/负的）需要的结合作用。进一步的GCN4蛋白质模型系统的设计正在进行中。
基金funding by the National Institutes of Health grant HD070487the New Jersey Agricultural Extension Station and USDA NIFA NC1184 in support of work described in this article
文摘This article provides a brief overview describing how two key signaling pathways, namely the integrated stress response and the mammalian target of rapamycin complex 1, work together to facilitate cellular adaptation to dietary amino acid insufficiency. A deeper understanding of these mechanisms is leading to identification of novel targets which aid in disease treatments, improve stress recovery and increase health span through slowed aging and enhanced metabolic fitness.
