植物碱性亮氨酸拉链(bZIP)蛋白的研究进展(二)———DNA结合特性、基因表达、功能及应用

植物碱性亮氨酸拉链(bZIP)蛋白在高等植物基因表达与调控中起重要作用。本文介绍了植物bZIP蛋白与DNA结合特性,探讨了它们的基因表达和功能,综述了它们在分子生物学和基因工程研究中的应用。 Abstract:Plant basic leucine zipper (bZIP) proteins play an important role in the expression and regulation of higher plant genes.The DNA-binding properties of plant bZIP protein are introduced first in this article.Then their expression and function are discussed.Finally,their application to the studies of molecular biology and genetic engineering is reviewed.     

Special Issue on “Plant Genomics”

正We are very pleased to announce a special issue,to be published in the fall of 2018,on "Plant Genomics"in the journal Genomics,ProteomicsBioinformatics(GPB).The development of genomics has greatly accelerated and even renovated the plant research.The sequencing of plant genomes has greatly facilitated the research on gene functions.The     

Plant Proteins Are Smaller Because They Are Encoded by Fewer Exons than Animal Proteins

Protein size is an important biochemical feature since longer proteins can harbor more domains and therefore can display more biological functionalities than shorter proteins. We found remarkable differences in protein length, exon structure, and domain count among different phylo-genetic lineages. While eukaryotic proteins have an average size of 472 amino acid residues (aa), average protein sizes in plant genomes are smaller than those of animals and fungi. Proteins unique to plants are ?81 aa shorter than plant proteins conserved among other eukaryotic lineages. The smaller average size of plant proteins could neither be explained by endosymbiosis nor subcellular compartmentation nor exon size, but rather due to exon number. Metazoan proteins are encoded on average by ?10 exons of small size [?176 nucleotides (nt)]. Streptophyta have on average only ?5.7 exons of medium size (?230 nt). Multicellular species code for large proteins by increasing the exon number, while most unicellular organisms employ rather larger exons (>400 nt). Among sub-cellular compartments, membrane proteins are the largest (?520 aa), whereas the smallest proteins correspond to the gene ontology group of ribosome (?240 aa). Plant genes are encoded by half the number of exons and also contain fewer domains than animal proteins on average. Interestingly, endosymbiotic proteins that migrated to the plant nucleus became larger than their cyanobacterial orthologs. We thus conclude that plants have proteins larger than bacteria but smaller than animals or fungi. Compared to the average of eukaryotic species, plants have ?34%more but ?20%smal-ler proteins. This suggests that photosynthetic organisms are unique and deserve therefore special attention with regard to the evolutionary forces acting on their genomes and proteomes.     

Preliminary investigation of sequence-independent DNA binding proteins in rat skeletal muscle sarcoplasmic reticulum and their function

To observe the binding of plasmid DNA to non-nuclear DNA binding proteins in sar-coplasmic reticulum (SR) and the effects of this binding on SR function, sarcoplasmic reticulum proteins in rat skeletal muscle were isolated by differential centrifuge and sucrose density-gradient centrifuge. The results showed that there are two sequence-independent DNA binding proteins in SR proteins, the molecular weights of which are 83 and 58 ku, respectively. Ca2 uptake and release of SR were remarkably promoted by the binding of plasmid DNA to DNA binding proteins in SR, the mechanism is probably through increasing of Ca2 -ATPase activity in SR and changing of character of Ca2 release channel ryanodine receptors induced by the binding. These results suggest that there exist DNA binding proteins in SR and its binding to DNA may affect Ca2 transport of SR.     

Special Issue on “Plant Genomics”

正We are very pleased to announce a special issue,to be published in the spring of 2019,on‘‘Plant Genomics’’in the journal Genomics,ProteomicsBioinformatics(GPB).The development of genomics has greatly accelerated and even renovated the plant research.The sequencing of plant genomes has greatly facilitated the research on gene functions.The multiple released genomes further promote the research on genome evolution and its functional     

Special Issue on “Plant Genomics”

正We are very pleased to announce a special issue,to be published in the fall of 2018,on‘‘Plant Genomics’’in the journal Genomics,ProteomicsBioinformatics(GPB).The development of genomics has greatly accelerated and even renovated the plant research.The sequencing of plant genomes has greatly facilitated the research on gene functions.The multiple released genomes further promote the research on genome evolution and its functional     

Special Issue on ‘‘Plant Genomics”

正We are very pleased to announce a special issue, to be published in the summer of 2019,on ‘‘Plant Genomics’’ in the journal Genomics, ProteomicsBioinformatics (GPB).The development of genomics has greatly accelerated and even renovated the plant research.The sequencing of plant genomes has greatly facilitated the research on gene functions. The multiple released genomes further promote the research on genome evolution and its functional     

Special Issue on “Plant Genomics”

正We are very pleased to announce a special issue,to be published in the spring of 2019,on"Plant Genomics"in the journal Genomics,ProteomicsBioinformatics(GPB).The development of genomics has greatly accelerated and even renovated the plant research.The sequencing of plant genomes has greatly facilitated the research on gene functions.The multiple released genomes further promote the research on genome evolution and its functional     

Special Issue on “Plant Genomics”

正We are very pleased to announce a special issue,to be published in Summer 2018,on "Plant Genomics" in the journal Genomics,ProteomicsBioinformatics(GPB).The development of genomics has greatly accelerated and even renovated the plant research.The sequencing of plant genomes has greatly facilitated the research on gene functions.The multiple released genomes further promote the research on genome evolution and its functional     

植物凝集素的功能

植物凝集素是来源于植物的一类能凝集细胞和沉淀单糖或多糖复合物的非免疫来源的非酶蛋白质。由于其对于单糖或糖复合物特异性结合的能力,使得其在如信号转导、免疫反应、植物防御等诸多信号过程中均具有重要作用。同时植物凝集素具有细胞凝集、抗病毒、抗真菌及诱导细胞凋亡或自噬等多种能力,因此在生命科学、医学及农业方面均有较好的研究价值和应用前景。综述了植物凝集素的研究历史和凝集素的主要功能,并对现阶段凝集素的重点应用做简要介绍。     

植物凝集素的超级家族

凝集素是一类专一、可逆地和糖类结合的蛋白质,迄今已经分离纯化并测定了氨基酸序列的凝集素已有不少,一些凝集素以及它们与配体糖相互结合的复合物的高级结构也已经给出,许多工作已深入到基因水平．就目前已有的知识,说明植物凝集素是一个庞大的蛋白质家族．     

Plant lectins,from ancient sugar‐binding proteins to emerging anti‐cancer drugs in apoptosis and autophagy

Ubiquitously distributed in different plant species, plant lectins are highly diverse carbohydrate‐binding proteins of non‐immune origin. They have interesting pharmacological activities and currently are of great interest to thousands of people working on biomedical research in cancer‐related problems. It has been widely accepted that plant lectins affect both apoptosis and autophagy by modulating representative signalling pathways involved in Bcl‐2 family, caspase family, p53, PI3K/Akt, ERK, BNIP3, Ras‐Raf and ATG families, in cancer. Plant lectins may have a role as potential new anti‐tumour agents in cancer drug discovery. Thus, here we summarize these findings on pathway‐ involved plant lectins, to provide a comprehensive perspective for further elucidating their potential role as novel anti‐cancer drugs, with respect to both apoptosis and autophagy in cancer pathogenesis, and future therapy.     

植物凝集素的分子生物学研究

植物凝集素是一类具有高度特异性糖结合活性的蛋白,含有一个或多个可与单糖或寡聚糖特异可逆结合的非催化结构域。它的糖结合特异性主要针对外源寡糖,主要生理功能是介异植物的防御反应。到目前为止已克隆了２２２个植物凝集素基因。作者就植物凝集素的分类、性质、功能、凝集素基因的克隆和凝集素的翻译后加工过程作一综述。     

Plant lectins: occurrence,biochemistry, functions and applications

Growing insights into the many roles of glycoconjugates in biorecognition as ligands for lectins indicates a need to compare plant and animal lectins. Furthermore, the popularity of plant lectins as laboratory tools for glycan detection and characterization is an incentive to start this review with a brief introduction to landmarks in the history of lectinology. Based on carbohydrate recognition by lectins, initially described for concanavalin A in 1936, the chemical nature of the ABH-blood group system was unraveled, which was a key factor in introducing the term lectin in 1954. How these versatile probes are produced in plants and how they are swiftly and efficiently purified are outlined, and insights into the diversity of plant lectin structures are also given. The current status of understanding their functions calls for dividing them into external activities, such as harmful effects on aggressors, and internal roles, for example in the transport and assembly of appropriate ligands, or in the targeting of enzymatic activities. As stated above, attention is given to intriguing parallels in structural/functional aspects of plant and animal lectins as well as to explaining caveats and concerns regarding their application in crop protection or in tumor therapy by immunomodulation. Integrating the research from these two lectin superfamilies, the concepts are discussed on the role of information-bearing glycan epitopes and functional consequences of lectin binding as translation of the sugar code (functional glycomics).     

植物外源凝集素及其在植物基因工程中的应用

植物外源凝集素及其基因研究近年来发展迅速 ,尤其是在植物基因工程中 ,植物外源凝集素越来越受到重视。本文介绍了植物外源凝集素的分类、分布、多样性、基本组成与结构、凝集素基因同源性、表达及生物学功能等。重点讨论了凝集素基因在植物基因工程中的应用     

Could plant lectins become promising anti‐tumour drugs for causing autophagic cell death?

Plant lectins, a group of highly diverse carbohydrate‐binding proteins of non‐immune origin, are ubiquitously distributed through a variety of plant species, and have recently drawn rising attention due to their remarkable ability to kill tumour cells using mechanisms implicated in autophagy. In this review, we provide a brief outline of structures of some representative plant lectins such as concanavalin A, Polygonatum cyrtonema lectin and mistletoe lectins. These can target autophagy by modulating BNIP‐3, ROS‐p38‐p53, Ras‐Raf and PI3KCI‐Akt pathways, as well as Beclin‐1, in many types of cancer cells. In addition, we further discuss how plant lectins are able to kill cancer cells by modulating autophagic death, for therapeutic purposes. Together, these findings provide a comprehensive perspective concerning plant lectins as promising new anti‐tumour drugs, with respect to autophagic cell death in future cancer therapeutics.     

A database analysis of jacalin-like lectins: sequence-structure-function relationships

Lectins are known to be important for many biological processes, due to their ability to recognize cell surface carbohydrates with high specificity. Plant lectins have been model systems to study protein-carbohydrate recognition, because individually they exhibit high sensitivity and as a group large diversity in recognizing carbohydrate structures. Although extensive studies have been carried out for legume lectins that have led to interesting insights into the sequence determinants of sugar recognition in them, frameworks with such specific correlations are not available for other plant lectin families. This study reports a large-scale data acquisition and extensive analysis of sequences and structures of beta-prism-I or jacalin-related lectins (JRLs) and shows that hypervariability in the binding site loops generates carbohydrate recognition diversity, a strategy analogous to that in legume lectins. Analyses of the size, conformation, and sequence variability in key regions reveal the existence of a common theme, encoded as a set of structural features over a common scaffold, in defining specificity. This study also points to the remarkable range of domain architectures, often arising out of gene duplication events in lectins of this family. The data analyzed here also indicate a spectacular variety of quaternary associations possible in this family of lectins that have implications for glycan recognition. These results thus provide sequence-structure-function correlations, an understanding of the molecular basis of carbohydrate recognition by beta-prism-I lectins, and also a rationale for engineering specific recognition capabilities in relevant molecules.     

植物糖生物学与糖链植物疫苗

植物糖生物学是研究植物与糖类互作机制、植物体内糖链与糖缀合物结构及生物学功能的科学,具体涉及糖信号、糖蛋白及其糖链功能、糖基转移酶及植物凝集素等研究方向。依据相关文献及实际研究经验,简要综述植物糖生物学的最新研究进展,其中重点介绍糖链植物疫苗并阐述其应用情况及作用机制。     

植物凝集素研究进展

植物凝集素广泛分布于植物界,它可以根据不同性质进行分类,按进化及结构相关性可以分为七个家族;豆科凝集素,单子叶植物甘露糖结构凝集素,含橡胶素结构域的几丁质结合凝集素,2型核糖体失活蛋白,葫芦科韧皮部凝集素,木菠萝素相关凝集素和苋科凝集素,在长期的进化过程中,它们形成几种不同的结合模体来识别一些外源多糖,在植物中未发现合适的内源性多糖受体。植物凝集素在生物学研究,农业和医学上有广泛的应用。