Molecular epidemiological study on pre-X region of hepatitis B virus and identification of hepatocyte proteins interacting with whole-X protein by yeast two-hybrid

AIM: To identify the pre-X region in hepatitis B virus (HBV)genome and to study the relationship between the genotype and the pre-X region. To investigate the biological function of whole-X (pre-X plus X) protein, we performed yeast two-hybrid to screen proteins in liver interacting with whole-X protein.METHODS: The pre-X region of HBV was amplified by polymerase chain reaction (PCR) method, and was cloned to pGEM Teasy vector. After the target region was sequenced, Vector 8.0 software was used to analyze the sequences. The whole-X bait plasmid was constructed by using yeast two-hybrid system 3. Yeast strain AH109 was transformed. After expression of the whole-X protein in AH109 yeast strains was proved, yeast two-hybrid screening was performed by mating AH109 with Y187 containing liver cDNA library plasmid. The mated yeast was plated on quadruple dropout medium and assayed for α-gal activity. The interaction between whole-X protein and the protein obtained from positive colonies was further confirmed by repeating yeast two-hybrid. After extracting and sequencing of plasmid from blue colonies, we carried out analysis by bioinformatics. RESULTS: After sequencing, 27 of 45 clones (60%) were found encoding the pre-X peptide. Eighteen of twenty-seven clones (66.7%) of pre-X coding sequences were found from genotype C. Five positive colonies that interacted with whole-X protein were obtained and sequenced; namely, fetuin B, UDP glycosyltransferase 1 family-polypeptide A9, mannose-P-dolichol utilization defect 1, fibrinogen-B beta polypeptide, transmembrane 4 superfamily member 4CD81 (TM4SF4).CONCLUSION: The pre-X gene exists in HBV genome.Genes of proteins interacting with whole-X protein in hepatocytes were successfully cloned. These results brought some new clues for studying the biological functions of whole-X protein.

Screening of genes of proteins interacting with p7 protein of hepatitis C virus from human liver cDNA library by yeast two-hybrid system

AIM: To investigate the biological function of p7 protein and to look for proteins interacting with p7 protein in hepatocytes.METHODS: We constructed p7 protein bait plasmid by doning the gene of p7 protein into pGBKT7, then transformed it into yeast AH109 (a type). The transformed yeast was mated with yeast Y187 (α type) containing liver cDNA library plasmid, pACT2 in 2xYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x-α-gal for selection and screening. After extracting and sequencing of plasmids from blue colonies, we performed sequence analysis by bioinformatics.RESULTS: Fifty colonies were selected and sequenced.Among them, one colony was Homo sapiens signal sequence receptor, seven colonies were Homo sapiens H19, seven colonies were immunoglobulin superfamily containing leucine-rich repeat, three colonies were spermatid peri-nuclear RNA binding proteins, two colonies were membrane-spanning 4-domains, 24 colonies were cancer-associated antigens, four colonies were nucleoporin 214 ku and two colonies were CLL-associated antigens.CONCLUSION: The successful cloning of gene of protein interacting with p7 protein paves a way for the study of the physiological function of p7 protein and its associated protein.

Screening of hepatocyte proteins binding to complete S protein of hepatitis B virus by yeast-two hybrid system

AIM: To investigate the biological function of complete S protein and to look for proteins interacting with complete S protein in hepatocytes.METHODS: We constructed bait plasmid expressing complete S protein of HBV by cloning the gene of complete S protein into pGBKT7, then the recombinant plasmid DNA was transformed into yeast AH109 (a type). The transformed yeast AH109 was mated with yeast Y187 (α type) containing liver cDNA library plasmid in 2xYPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/Trp-Leu-His-Ade) containing X-α-gal for selection and screening. After extracting and sequencing of plasmids from positive (blue) colonies, we underwent sequence analysis by bioinformatics.RESULTS: Nineteen colonies were selected and sequenced.Among them, five colonies were Homo sapiens solute carrier family 25, member 23 (SLC25A23), one was Homo sapiens calreticulin, one was human serum albumin (ALB)gene, one was Homo sapiens metallothionein 2A, two were Homo sapiens betaine-homocysteine methyltransferase,three were Homo sapiensNa+ and H+ coupled amino acid transport system N, one was Homo sapiens CD81 antigen (target of anti-proliferative antibody 1) (CD81), three were Homo sapiens diazepam binding inhibitor, two colonies were new genes with unknown function.CONCLUSION: The yeast-two hybrid system is an effective method for identifying hepatocyte proteins interacting with complete S protein of HBV. The complete S protein may bind to different proteins i.e., its multiple functions in vivo.

Screening of hepatocyte proteins binding to NS5ABP37 protein by yeast-two hybrid system

Objective To investigate the biological function of NS5ABP37 and to look for proteins interacting with NS5ABP37 protein in hepatocytes.Methods We constructed bait plasmid expressing NS5ABP37 protein of hepatitis C virus(HCV)by cloning the gene of NS5ABP37 protein into pGBKT7,then the recombinant plasmid DNA was transformed into yeast AH109(α type).The transformed yeast AH109 was mated with yeast Y187(α type)containing liver cDNA library plasmid in 2×YPDA medium.Diploid yeast was plated on synthetic dropout nutrient medium(SD/-Trp-Leu-His-Ade)containing X-α-gal for selection and screening.After extracting and sequencing of plasmids from positive(blue)colonies,we made a sequence analysis by bioinformatics.Results We screened twenty-five proteins binding to NS5ABP37,including Homo sapiens cyclin I(CCNI)gene,Homo sapiens matrix metallopeptidase 25(MMP25)and Homo sapiens talin 1.Conclusion The yeast-two hybrid system is an effective method for identifying hepatocyte proteins interacting with NS5ABP37 of HCV.And the biological function of NS5ABP37 may be associated with glycometabolism,lipid metabolism and apoptosis.

Shared and discrete interacting partners of ELL1 and ELL2 by yeast two-hybrid assay

ELL2 (eleven-nineteen lysine-rich leukemia transcription elongation factor), a component of a larger complex with pTEFb (cyclin T and CDK9) and AF4, is up-regulated in plasma cells where it influences mRNA processing by increasing exon skipping and enhancing proximal poly (A) site use. ELL2 is needed to produce the secretory-specific Ig heavy chain mRNA while ELL1 mRNA does not change in abundance with B cell stages. To investigate the potential interactions of other proteins with the ELL1 and ELL2 proteins, we preformed yeast two-hybrid studies. HSP40 and Testin were found to bind to ELL2 in its amino-terminal half. PCNA binds to ELL2 in a region encompassing amino acids 186 - 344. The potent transcription factors HIF1 α and ZNF622 interact with both ELL1 and 2 in the central, proline rich region. Meanwhile, BBS2 and ING3 interact with ELL1 but not ELL2 in this central proline-rich region. Many of the ELL-interacting-proteins uncovered in the two-hybrid screen are tumour suppressors that may work through the ELL: pTEFb complex to suppress or activate sets of genes in plasma cells.

Construction of a Three-frame Yeast Two-hybrid cDNA Library of Fusarium oxysporum

A specialized test of two-hybrid library type three-frame cDNA yeast for Muskmelon Fusarium oxysporum using the switching mechanism at the 5'end of RNA template(SMART)technology was constructed to screen for interaction protein genes for wilt disease and to further research the molecular mechanisms of Fusarium oxysporum pathogenesis to explain the interactions between plant and pathogen.A 500-bp cDNA was purified and extracted using SMART and LD-PCR technology to synthesize ds cDNA and was then homogenized and purified to remove the fragments.After processing,the ds cDNA was connected to three types of reading frame pGADT7-SfiI carriers,and the three connection products in E.coli Electrocell were used to build the primary cDNA library.The titer of three ORF cDNA primary library storage capacities was 2.6×10^6,1.8×10^6 and 3×10^6 cfu;the PCR identification of the ORF 1 and 2 gene recombination rate was 94%,the ORF 3 gene recombination rate was 100%,and the insert length distribution was 0.5-4.0 kb as a single band.To reach the quality requirements for library construction,three kinds of reading frame cDNA primary libraries were mixed and amplified,and the plasmid was transformed into the Y187 yeast strain.The titer of the Y187 yeast library was determined to be 3.5×107 cfu?mL-1,and the base of the yeast library was approximately 1 600 000 cfu.The results showed that the construction of muskmelon Fusarium-specific two-hybrid library type three-frame cDNA yeast had a higher reservoir capacity and recombination rate and met the yeast two-hybrid screening requirements.

Screening of FOXP3-interacted proteins by yeast two-hybrid technique

屏蔽由酵母与 Treg 说明因素 forkhead 盒子蛋白质 P3 (FOXP3 ) 交往的蛋白质的目的二混血儿的系统。方法人的 FOXP3 基因被巢 RT-PCR 从外部血 mononuclear 细胞(PBMC ) 放大并且插入了到 plasmid pGBKT7 构造诱饵向量，然后，在宿主酵母紧张 AH109 的诱饵向量的自我激活和毒性被观察。此后，一个人的肝 cDNA 图书馆被诱饵向量屏蔽。积极克隆被营养素缺乏的文化和 back-hybridizing 外面选择。从候选人的序列积极克隆被生物信息学方法爆炸并且分析。编码 FOXP3 的构造诱饵向量没在酵母 AH109 被发现自我激活和毒性的结果。与 FOXP3 交往了包括肿瘤蛋白质 D52，拼接的三蛋白质因素 3b 子单元 1 并且假想蛋白质，被识别。与 FOXP3 交往的结论三新候选人蛋白质被这酵母外面选择二混血儿的系统和图书馆，它可以在 Treg 便于 FOXP3 的进一步的学习。

Construction and Identification of a Yeast Two-Hybrid Bait Vector and Its Effect on the Growth of Yeast Cells and the Self-Activating Function of Reporter Genes for Screening of HPV18 E6-Interacting Protein

By using a yeast two-hybrid system,a yeast two-hybrid bait vector was constructed and identified for screening of the HPV18 E6-interacting proteins,and its effects on the growth of yeast cells and the activation of reporter genes were investigated.Total mRNA extracted from Hela cells was reversely transcribed into cDNA.Fragment of HPV18 E6 cDNA was amplified using RT-PCR and directly ligated to the pGBKT7 vector.The recombinant plasmid was confirmed by restriction endonuclease analysis and DNA sequencing.Th...

Screening proteins that interact with mutant superoxide dismutase 1 from familial amyotrophic lateral sclerosis using a yeast two-hybrid system

The present study screened a human fetal brain cDNA library to find the proteins that interact with mutant superoxide dismutase 1 （SOD1） using a yeast two-hybrid system. Using BLAST software, 15 real proteins which interacted with mutant SOD1 were obtained, including 8 known proteins （protein tyrosine-phosphatase non-receptor type 2, TBCl D4, protein kinase family, splicing factor, arginine/serine-rich 2, SRC protein tyrosine kinase Fyn, β-sarcoglycan; glycine receptor a2, microtubule associated protein/microtubule affinity-regulating kinase 1, ferritin H chain）, and 7 unknown proteins. Results demonstrated interaction of mutant SOD1 with microtubule associated protein/microtubule affinity-regulating kinase 1 and β-sarcoglycan.

Improved methods for cloning and detection in the yeast two hybrid assay

The yeast two-hybrid (Y2H) mating assay is a powerful method for detecting protein-protein interactions. Firstly, the gene of interest is cloned into specific Y2H vectors. Although multiple innovations in cloning methods were made in the past two decades, the conventional cloning method of restriction-enzyme (RE) digestion followed by ligation is still widely used. Unfortunately, many researchers, especially new-comers, often encounter difficulties in cloning a gene into a desired vector. Secondly, interaction between two proteins is commonly detected by growth of the diploids in specific media. This step takes about two weeks. Here, we describe improved cloning and detection procedures for the Y2H assay that accelerate the research progress. The changes in procedures involve running an agarose gel after the doubly digested vector and insert are ligated in the cloning step to determine the efficiency of RE digestion and ligation, and performing an additional replica-plating on plates for earlier assessment of interaction in the detection step. We show an example of Y2H interaction between Trs23 and Trs120 (respective subunits of TRAPP I and TRAPP II), as a proof of concept. By following the improved methods described here, the chances of successful cloning increased and the time for the whole Y2H experimental process is significantly shorter.

Screening of Host Proteins Interacting with PorcineEpidemic Diarrhea Virus (PEDV) N Protein by YeastTwo-hybrid System

[Objective] The paper was to obtain host proteins interacting with porcine epidemic diarrhea virus （PEDV） N protein. [Method] The re-combinant vector pGBKT7-N of PEDV N gene was constructed and used as the bait plasmid to screen the proteins interacting with N protein ofPEDV from the cDNA library of porcine alveolar macrophage （PAM） by yeast two-hybrid method. [Result] There was no toxicity and self activationof bait protein in yeast hybridization system, and six proteins （FTH1, LGALS3, CORO1C, SNRPG, KRTAP5-3, ZNF598） interacting with N proteinwere indentified. It was confirmed that LGALS3 and SNRPG had specific interaction with N protein by return experiment and co-immunoprecipitation（CoIP） test. [Conclusion] The study lays a foundation for further studying the function of PEDV N protein and the pathogenic mechanism of PEDV.

Screening and identification of binding proteins to interferon-α from a cDNA library by yeast-two hybrid system

The aim of this study is to screen proteins interacting with interferon-α (IFN-α). The IFN-α gene was amplified by polymerase chain reaction (PCR) and cloned into pGBKT7 vector, then the resulted pGBKT7-IFN-α vector was transformed into yeast strain AH109. The transformed yeast AH109 was mated with yeast Y187 containing liver cDNA library plasmid in 2×YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade and SD/-Trp-Leu-His) containing X-α-gal for selection. After plasmid extraction and enzyme cutting analysis, the blue colonies were subjected to sequence analysis and the results were analyzed by bioinformatics. The results showed that IFN-α was successful cloned into the pGBKT7 vector. IFN-α was expressed and there was no self-activation and toxicity in AH109. Thirty-four positive colonies were obtained after yeast-two hybrid technique screening. After sequence analysis, eight clones were found to have a binding effect with IFN-α protein. IFN-α was successfully cloned into the pGBKT7 vector. IFN-α protein was expressed and there was no self-activation and toxicity in AH109. Eight proteins that interacted with IFN-α, including vitronectin, fibrinogen A alpha polypeptide, HIV-1 Tat interactive protein 2, arginase, NADH dehydrogenase 1 beta subcomplex, transferrin receptor 2 alpha (TFR2), HCC-1, alcohol dehydrogenase IB (ADH1B) have been identified as IFN-α-binding proteins.

橡胶树形成层组织的酵母双杂交cDNA文库构建及HbHDA6互作蛋白筛选

次生乳管是天然橡胶合成和贮存的场所,是由橡胶树树干树皮中维管形成层细胞分裂分化而来。次生乳管的数量与天然橡胶产量直接相关,而这些乳管的数量取决于形成层分化次生乳管的频率(乳管分化能力),是橡胶树产量育种的主要指标。前期研究中,我们发现组蛋白去乙酰化酶(HDA)抑制剂曲古抑菌素A(TSA)能诱导橡胶树乳管分化且组蛋白去乙酰化酶基因(HbHDA6)能够参与橡胶树乳管分化调控。由于组蛋白乙酰化修饰调控橡胶树次生乳管分化的分子机制尚未阐明,因此该文使用冠菌素(COR)诱导橡胶树形成层分化产生次生乳管的实验系统,以分离形成层组织为材料,构建酵母双杂交cDNA文库,以HbHDA6基因为诱饵来筛选酵母双杂交文库,确定与HbHDA6相互作用的蛋白。结果表明:(1)利用Gateway技术构建的均一化COR诱导橡胶树形成层组织的酵母双杂交cDNA文库,初级文库的容量为6.34×10^(6)CFU·mL^(-1),总单克隆数为1.27×10^(7),文库重组率为100%;次级文库的容量为7.72×10^(6)CFU·mL^(-1),总单克隆数为1.54×10^(7),文库重组率为100%。初级文库和次级文库的插入片段平均长度分别为1.1 kb和1.2 kb。(2)成功构建了筛选HbHDA6互作蛋白的pGBKT7-HbHDA6诱饵载体,并确认无自激活活性。(3)使用该诱饵载体对构建的酵母双杂交cDNA文库进行筛选,并通过NCBI_BLAST比对和去除重复以后,获得了22个与HbHDA6发生互作的蛋白,包括CLP1、ERF3、ERF4、HSP82、LARP6a、APT5、PP2A、FBA6等。该研究成果为解析组蛋白乙酰化修饰调控橡胶树次生乳管分化的分子机制提供了理论基础,为转基因改良橡胶树的产胶潜力提供了候选基因,为高性能天然橡胶遗传改良育种提供了新线索。

大豆GmNF-YA13互作蛋白的筛选及鉴定

大豆GmNF-YA13蛋白是一个核转录因子Y(NF-Y),在干旱和高盐响应过程中均发挥重要作用。为研究其抗旱和耐盐的作用机理,寻找GmNF-YA13的互作蛋白,构建pGBKT7-GmNF-YA13诱饵载体,采用酵母双杂交筛选大豆酵母文库,并进行X-α-gal染色验证。结果显示:酵母双杂交获得85个阳性克隆,测序分析后得到36个候选的互作蛋白。功能预测显示互作蛋白主要参与生长发育、胁迫响应、能量代谢、转录调控和信号转导等生物过程。选择GmUVR8、GmCML41、GmFbox13和GmFBA与诱饵pGBKT7-GmNF-YA13进行一对一验证,只有GmFBA能与GmNF-YA13发生相互作用,预示GmNF-YA13功能的发挥需要GmFBA的参与。该结果可为NF-YA抗逆分子网络的研究提供基础。

长足大竹象信息素结合蛋白CbuqPBP2互作蛋白的筛选与验证

【目的】筛选长足大竹象(Cyrtotrachelus buqueti)信息素结合蛋白CbuqPBP2的互作蛋白,为实现利用信息物质对长足大竹象种群持续控制提供参考。【方法】利用GST pull-down联合质谱技术,对长足大竹象信息素结合蛋白CbuqPBP2的互作蛋白进行筛选、鉴定和分析,并采用酵母双杂交试验验证了CbuqPBP2与信息素结合蛋白CbuqPBP1的特异性互作。【结果】GST pull-down共筛选出45个与长足大竹象信息素结合蛋白CbuqPBP2特异性结合的候选互作蛋白,包括CbuqPBP1、ND2、CYTB。这些互作蛋白主要参与细胞过程、定位、代谢过程、应激反应以及生物调控等多个生物学过程。使用酵母双杂交体系,构建了pGADT7-PBP1重组猎物质粒与pGBKT7-PBP2重组诱饵质粒,通过诱饵质粒毒性检测和自激活检测,表明重组诱饵质粒对Y2HGold酵母菌无毒性作用。共转化验证结果显示,诱饵质粒pGBKT7-PBP2共转化酵母菌株能够在TDO培养基上生长。【结论】CbuqPBP2和CbuqPBP1之间有相互作用,不同信息素结合蛋白间的互作对深入理解长足大竹象嗅觉感受机制提供了新的思路。

木薯花叶病毒AC4蛋白与AtPARN互作研究

木薯(Manihot esculenta Crantz)作为重要的热带作物,是全球六大粮食作物之一,并为全球近七亿人口提供主粮,然而病毒侵染引起的病害在全球范围内严重威胁木薯产业的发展。木薯花叶病毒病(cassava mosaic disease,CMD)是最有威胁的病害之一,造成严重的经济损失。斯里兰卡木薯花叶病毒(SriLankancassavamosaicvirus,SLCMV)是引发木薯花叶病的病原物之一,SLCMV是典型的双组分双生病毒,其基因组由DNA-A和DNA-B两个环状组分组成。无义介导的mRNA降解(nonsense-mediatedmRNAdecay,NMD)是真核细胞mRNA降解的主要途径之一,也是真核生物普遍存在的抗病毒防御机制。越来越多的研究显示,NMD不仅是真核生物重要的mRNA数量、质量调控机制,还与转录后基因沉默(post transcriptional gene silencing,PTGS)同样能降解病毒RNA,是真核生物普遍存在的抗病毒防御机制。NMD的mRNA衰减过程包括PTC的识别、脱腺苷酸、脱帽和最后的核酸外切酶降解4个过程,UPF1、PARN、DCP2和XRN4分别是上述4个过程中的关键蛋白。病毒是专性寄生生物,必须逃避或耐受寄主细胞的降解,才能成功感染。聚腺苷酸特异性核糖核酸酶[poly(A)-specific ribonuclease,PARN]是NMD信号通路的一个关键因子。目前,关于SLCMV抵御寄主NMD的分子机制尚不明确。本研究采用酵母双杂交(yeast two-hybrid system)和荧光双分子互补(bimolecular fluorescence complementation,BiFC)试验证明斯里兰卡木薯花叶病毒(SLCMV)编码的沉默抑制子AC4与拟南芥PARN相互作用。据此推测SLCMV AC4蛋白可能通过与AtPARN相互作用而抑制寄主NMD的病毒防御功能帮助病毒逃避或耐受寄主细胞的降解。研究结果为阐明木薯花叶病毒调控寄主NMD抗病毒防御功能的分子机理奠定基础。

橡胶树HbPIP2;3的亚细胞定位与多聚化分析

水通道蛋白是一类高效转运水分子的膜内在蛋白,其在生物膜上以四聚体的形式起作用。天然橡胶在橡胶树的乳管细胞中特异合成,并在割胶过程以胶乳的形式被排出。胶乳系乳管细胞的胞质成分,其含水量高达70%,水分通过调节胶乳的粘稠度和乳管膨压进而影响橡胶树的产排胶能力,是决定胶乳产量的关键因素。前期研究显示,橡胶树乳管的水分平衡主要由质膜内在蛋白(plasma membrane intrinsic protein,PIP)特别是HbPIP2;3介导。为揭示HbPIP2;3调控乳管水分平衡的分子机制,本研究采用RT-PCR技术对其861 bp的编码区进行分离。序列分析显示:HbPIP2;3预测编码286个氨基酸,理论分子量为30.58 kDa,等电点为8.50,不稳定系数为31.68,总平均疏水指数为0.449,为稳定的疏水型碱性蛋白;该蛋白含有保守的MIP结构域,其中包括6个典型的跨膜螺旋和2个半螺旋;基于同源建模的3D结构预测显示其可以形成同源四聚体。生物信息学预测和在烟草叶片中的亚细胞定位分析显示,HbPIP2;3定位在细胞膜,这同时也得到了双分子荧光互补(bimolecular fluorescence complementation,BiFC)实验的证实。BiFC实验显示,HbPIP2;3可在细胞膜上形成同源四聚体,这进一步得到酵母双杂交结果的验证。本研究结果表明,HbPIP2;3可通过同源四聚体的方式调控乳管的水分平衡,但是否存在异源互作模式还有待进一步研究。

橡胶树水通道蛋白HbPIP2;7的亚细胞定位与多聚化分析

天然橡胶在橡胶树的乳管细胞中特异性合成。用于割胶的成熟乳管与邻近的薄壁细胞之间不存在胞间连丝,故乳管的水分转入只能通过细胞膜定位的PIP水通道蛋白来实现。为探讨乳管水分平衡的分子机制,研究对1个高丰度表达的PIP基因HbPIP2;7进行了克隆,在此基础上对其编码蛋白的亚细胞定位和多聚化特性进行了分析。结果表明:HbPIP2;7的编码区全长837 bp,预测编码278 AA,理论分子量为29.56 kDa、等电点为9.11、不稳定系数为29.89、总平均疏水指数为0.526,含有1个保守的MIP结构域及6个典型的跨膜螺旋,预测以四聚体的形式起作用。生物信息学预测和在烟草中的亚细胞定位分析均显示,HbPIP2;7定位在细胞膜。双分子荧光互补和酵母双杂交实验均表明,HbPIP2;7不能形成同源多聚体,推测HbPIP2;7主要通过异源互作的方式参与橡胶树乳管的水分平衡。

陆地棉抗黄萎病基因GhENODL6互作蛋白筛选

研究发现陆地棉ENODL6基因具有抗黄萎病功能。为进一步揭示其在棉花抗黄萎病过程中发挥的作用,通过Nimble Cloning技术将GhENODL6插入酵母表达载体pNC-GBKT7,构建了重组质粒pNC-GBKT7-ENODL6。重组质粒转入酵母菌Y2HGold后可在DDO培养基上正常生长,但不能生长于QDO/X/A培养基,表明GhENODL6蛋白对酵母宿主无毒害作用,没有自激活活性。将携带pNC-GBKT7-ENODL6诱饵载体的Y2HGold酵母菌与cDNA文库进行杂交筛选,结果获得一个能够显示蓝色的菌落。通过PCR扩增,在蓝色酵母菌中获得一段526 bp的非载体插入片段,与陆地棉基因组内基因WRKY47序列高度一致。通过同源扩增,从陆地棉中克隆到WRKY47开放读码框,全长1 587 bp,编码528个氨基酸残基。再次利用酵母双杂交技术确认了WRKY47与GhENODL6之间存在互作关系。综上,构建了重组载体pNC-GBKT7-ENODL6,并鉴定到与GhENODL6互作的蛋白WRKY47。

白菜种子cDNA酵母文库的构建及BrTTG1互作蛋白的筛选及分析

【目的】通过构建白菜种子的cDNA文库,筛选WDR 40蛋白TRANSPARENT TESTA GLABRA 1(TTG1)的互作蛋白,探究TTG1参与MBW三元复合体调控种皮原花青素形成的分子机制。【方法】以棕籽白菜自交系‘B147’的种子为材料,提取总RNA并建立cDNA文库,通过gateway技术构建诱饵载体pGBKT7-TTG1并进行酵母双杂交筛库。【结果】酵母文库库容为1.2×10^(7)CFU,文库滴度是5.0×10^(7)CFU/mL,插入片段平均长度大于1000 bp,诱饵载体在酵母中无自激活活性。通过构建的诱饵载体pGBKT7-TTG1与构建的cDNA文库杂交,共获得了38个阳性互作蛋白,功能预测显示其中一个蛋白注释为MYB转录因子,注释为MYB73,序列分析结果显示该基因含有R2R3-MYB型抑制子保守基序C1和C2,推测该基因为白菜中参与种皮颜色形成的R2R3-MYB型抑制子,暗示着白菜中可能存在不同MYB转录因子参与的调控网络,影响着原花青素的形成。【结论】本研究构建了白菜种子组织的酵母双杂交cDNA文库,获得了38个TTG1阳性互作蛋白,首次挖掘到了可能影响白菜种皮颜色原花青素形成的R2R3-MYB型抑制子MYB73,为后期探究白菜种皮原花青素的调控网络奠定良好的基础。