To construct a high-quality Panax ginseng cDNA library, transcription factors binding to the P. ginseng PgD14 gene promoter were screened by yeast one-hybrid, and proteins interacting with the P. ginseng Pgpht2-1 gene-encoded protein were screened by yeast two-hybrid. In this study, root tissues of P. ginseng were used as materials. Gateway technology was used to construct the P. ginseng yeast one-hybrid library, and duplex-specific nuclease(DSN) homogenization technology was used to construct the P. ginseng yeast two-hybrid library. The pAbAi-PgD14-Pro961 vector was used as bait to screen candidate transcription factors that might bind to the PgD14 gene promoter from the yeast one-hybrid library, and the pGBKT7-Pgpht2-1 vector was used as bait to screen candidate proteins that might interact with the Pgpht2-1 gene-encoded protein from the yeast two-hybrid library. The yeast one-hybrid library had a size of 1.20×10~7 CFU, a recombination rate of 100%, and an average inserted fragment length of more than 1 000 bp. The yeast two-hybrid library had a size of 1.832×10~5 CFU, a recombination rate of 100%, and an average inserted fragment length of about 1 000 bp. The recombinant vectors pAbAi-PgD14-Pro961 and pGBKT7-Pgpht2-1 were transformed into Y1HGold and AH109 strains, respectively, and interacting proteins were screened by yeast one-hybrid and yeast two-hybrid. As a result, 54 transcription factors that could bind to the PgD14 gene promoter of P. ginseng and 42 proteins that may interact with the protein encoded by the Pgpht2-1 gene were identified. This study successfully constructed the P. ginseng yeast one-hybrid and yeast two-hybrid cDNA libraries, laying a foundation for subsequent studies on the functions of the P. ginseng PgD14, Pgpht2-1, and other genes.
Panax/metabolism* ; Two-Hybrid System Techniques ; Plant Proteins/metabolism* ; Gene Library ; Plant Roots/chemistry* ; Protein Binding ; Transcription Factors/metabolism* ; Promoter Regions, Genetic

OBJECTIVE: To screen proteins interacting with ring finger protein 216(RNF216) through yeast two hybrid experiment, and further clarify the role of RNF216 in the pathogenesis of gonadotropin-releasing hormone deficiency. METHODS: A recombinant expression vector pGBKT7-RNF216 was constructed and transformed into yeast Y2HGold, which was hybridized with a human cDNA library in order to screen proteins interacting with RNF216. The interaction was verified in yeast Y2HGold. RESULTS: A recombinant expression vector pGBKT7-RNF216 was successfully constructed and expressed in yeast Y2HGold. Filamin B (FLNB) was identified by yeast two hybrid experiment, and their interaction was verified in yeast Y2HGold. CONCLUSION An interaction between FLNB and RNF216 was identified through yeast two hybrid experiment. RNF216 may affect the proliferation and migration of GnRH neurons by regulating FLNB or FLNB/FLNA heterodimers.
Gene Library ; Gonadotropin-Releasing Hormone/genetics* ; Humans ; Proteins ; Two-Hybrid System Techniques ; Ubiquitin-Protein Ligases/genetics*

5-HT₆ receptor (5-HT₆R) is implicated in cognitive dysfunction, mood disorder, psychosis, and eating disorders. However, despite its significant role in regulating the brain functions, regulation of 5-HT₆R at the molecular level is poorly understood. Here, using yeast two-hybrid assay, we found that human 5-HT₆R directly binds to neuro-oncological ventral antigen 1 (Nova-1), a brain-enriched splicing regulator. The interaction between 5-HT₆R and Nova-1 was confirmed using GST pull-down and co-immunoprecipitation assays in cell lines and rat brain. The splicing activity of Nova-1 was decreased upon overexpression of 5-HT₆R, which was examined by detecting the spliced intermediates of gonadotropin-releasing hormone (GnRH), a known pre-mRNA target of Nova-1, using RT-PCR. In addition, overexpression of 5-HT₆R induced the translocation of Nova-1 from the nucleus to cytoplasm, resulting in the reduced splicing activity of Nova-1. In contrast, overexpression of Nova-1 reduced the activity and the total protein levels of 5-HT₆R. Taken together, these results indicate that when the expression levels of 5-HT₆R or Nova-1 protein are not properly regulated, it may also deteriorate the function of the other.
Animals ; Brain ; Cell Line ; Cytoplasm ; Eating ; Gonadotropin-Releasing Hormone ; Humans ; Immunoprecipitation ; Mood Disorders ; Psychotic Disorders ; Rats ; RNA Precursors ; RNA-Binding Proteins ; Serotonin ; Two-Hybrid System Techniques

The study is aimed to construct high quality Salvia miltiorrhiza cDNA library and obtain the SmJAZ8 gene of S. miltiorrhiza by yeast two-hybrid system. In this study， full-length cDNA was synthesized from roots， stems， leaves， flowers and hairy roots of S. miltiorrhiza. The full-length cDNA library was synthesized by SMART method and constructed with DSN homogenization technique. The results showed that the library capacity was 1.45×10⁶， the recombination rate was 100%， and the average size of the insert was 500-2 000 bp. The recombinant vector of pDEST-pGADT7-SmJAZ8 was constructed and transformed into Y2HGold strain. The interaction protein was screened by yeast two-hybrid system. The DnaJ protein and UBQ protein were screened by yeast two-hybrid system. This study has successfully constructed a full-length cDNA library of S. miltiorrhiza， and laid the foundation for the follow-up study on functional gene screening and gene function of S. miltiorrhiza.
Co-Repressor Proteins ; genetics ; DNA, Complementary ; Gene Library ; Plant Proteins ; genetics ; Salvia miltiorrhiza ; genetics ; Two-Hybrid System Techniques

Bacterial two-hybrid system is a newly developed method for studying protein-protein interactions. However, in our studies of the interaction of regulatory proteins in Streptomyces, it was found that the bacterial two-hybrid system is not sensitive enough by the blue-and-white selection on X-gal plate. To overcome this drawback, the reason of false positive clone was firstly determined, which was the disturbance of other direct or indirect regulation on lacZ promoter. Then the disturbance was diluted by introducing multicopy lacZ promoter, which drive another reporter gene gfp. By such design, the sensitivity of the modified bacterial two-hybrid system was significantly inproved and the two different reporters also help to decrease the rate of the false positive clones. Further the evaluation of the modifiedd bacterial two-hybrid system indicated that the sensitivity was significantly improved.
Bacteria ; Genes, Reporter ; Promoter Regions, Genetic ; Protein Interaction Mapping ; methods ; Two-Hybrid System Techniques

To construct a bait expression vector containing the duck circovirus Cap gene for use in the yeast two-hybrid system, the whole cap codon-optimized gene was inserted into pGBKT7 vector and confirmed by PCR, restriction enzyme digestion, and sequence analysis. After transformation into a Y2HGold yeast strain, the expression of Cap protein was analyzed by Western blotting. Toxicity and self-activation of the bait protein were detected using different dropout minimal base. PCR reaction, restriction enzyme digestion, and sequencing analyses indicated that the duck circovirus Cap gene was correctly inserted into pG- BKT7. Western blotting showed that the whole Cap protein was expressed. The recombinant bait protein had no toxicity and self-activation. Therefore, the bait vector with the Cap gene was constructed successfully, providing a foundation for future screening for interacting proteins in the yeast two-hybrid system.
Animals ; Capsid Proteins ; genetics ; metabolism ; Circovirus ; classification ; genetics ; isolation & purification ; Cloning, Molecular ; Ducks ; Genetic Vectors ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; Saccharomyces cerevisiae ; genetics ; metabolism ; Two-Hybrid System Techniques

OBJECTIVETo identify protein-protein interaction partners of PER1 (period circadian protein homolog 1), key component of the molecular oscillation system of the circadian rhythm in tumors using bacterial two-hybrid system technique.

METHODSHuman cervical carcinoma cell Hela library was adopted. Recombinant bait plasmid pBT-PER1 and pTRG cDNA plasmid library were cotransformed into the two-hybrid system reporter strain cultured in a special selective medium. Target clones were screened. After isolating the positive clones, the target clones were sequenced and analyzed.

RESULTSFourteen protein coding genes were identified, 4 of which were found to contain whole coding regions of genes, which included optic atrophy 3 protein (OPA3) associated with mitochondrial dynamics and homo sapiens cutA divalent cation tolerance homolog of E. coli (CUTA) associated with copper metabolism. There were also cellular events related proteins and proteins which are involved in biochemical reaction and signal transduction-related proteins.

CONCLUSIONIdentification of potential interacting proteins with PER1 in tumors may provide us new insights into the functions of the circadian clock protein PER1 during tumorigenesis.

Base Sequence ; Cell Line, Tumor ; Escherichia coli ; genetics ; metabolism ; Humans ; Molecular Sequence Data ; Neoplasms ; genetics ; metabolism ; Period Circadian Proteins ; genetics ; metabolism ; Protein Binding ; Proteins ; genetics ; metabolism ; Two-Hybrid System Techniques

In order to identify host factors which interact with the movement protein (MP) of Apple chlorotic leaf spot virus (ACLSV), ACLSV MP was cloned into the bait vector pGBKT7 and used to screen a cDNA library of Malus sylvestris cv. R12740-7A, which had previously been constructed by yeast two-hybrid sequencing transformation. The protein functions of the identified host factors were determined according to their gene annotations in GenBank. The result showed that the bait plasmid pGBKT7-MP showed no virulence or self-activating effect on yeast strain Y2H Gold. Sixty-nine interactor proteins were identified, which were divided into the following 10 classes according to their described functions: hydrolases; pathogenesis-related proteins; DNA binding proteins; phosphatases; ligases; proteins with catalytic activity; phenylalanine ammonialyases; peroxidases; NAD binding proteins; and proteins of unknown function. Bioinformatic analysis of gene homology suggested that phosphatases, pathogenesis-related proteins and glyceraldehyde-3-phosphate dehydrogenase A may play an important role in the interaction between virus and host. This study may provide a theoretical basis for the further study of viral pathogenesis and virus-host interaction mechanisms.
Flexiviridae ; genetics ; metabolism ; Malus ; genetics ; metabolism ; virology ; Molecular Sequence Data ; Plant Diseases ; genetics ; virology ; Plant Proteins ; genetics ; metabolism ; Plant Viral Movement Proteins ; genetics ; metabolism ; Protein Binding ; Two-Hybrid System Techniques

OBJECTIVETo identify the binding site position of the hepatitis B virus (HBV) X protein (HBx) functional interaction with the cytochrome C oxidase subunit III (COX III, a key regulator of mitochondrial function) by using a yeast two-hybrid system.

METHODSTwo fragments of HBx mutants (X1 1-72aa and X2 1-117aa) were amplified by PCR and inserted into the bait plasmid pAS2-1.The resultant mutant plasmids were transfected into yeast cells using the lithium acetate-method.PCR and gene sequencing were used to confirm that the mutant fragments were expressed properly in yeast cells.Western blotting was used to verify that the mutant proteins were translated accurately in the yeast cells.Filter assay was used to exclude autoactivated mutants.Hybridization in solid medium and beta-gal activity detection were used to determine the precise position of the binding site for HBx and COX III interaction.

RESULTSThe two mutant plasmids containing HBx 1-72aa and 1-117aa respectively were successfully constructed and the mutants were both properly expressed and translated in yeast cells; no autoactivated mutants were detected throughout the experimental process.The binding site of HBx and COX III was found to be encompass the amino acids 72 through 117 of HBx.

CONCLUSIONAmino acids 72 through 117 of HBx are the key domain of the HBx functional interaction With COX III; this domain may represent a useful target for molecular-based therapies to treat HBV-related diseases.

Electron Transport Complex IV ; metabolism ; Hepatitis B virus ; metabolism ; Plasmids ; Polymerase Chain Reaction ; Protein Binding ; Trans-Activators ; metabolism ; Transfection ; Two-Hybrid System Techniques

OBJECTIVEThe protozoan Toxoplasma gondii expresses large amounts of a 37 kDa Type 2C serine-threonine phosphatase, the so-called TgPP2C which has been suggested to contribute to parasite growth regulation. Ectopic expression in mammalian cells also indicated that the enzyme could regulate growth and survival. In this study, we aimed to investigate the interaction of TgPP2C with human SSRP1 (structure-specific recognition protein 1) and the effects of TgPP2C on cell viability.

METHODSThe yeast two hybrid system, His-tag pull-down and co-immunoprecipitation assays were used to confirm the interaction of TgPP2C with SSRP1 and determine the binding domain on SSRP1. The evaluation of cell apoptosis was performed using cleaved caspase-3 antibody and Annexin-V/PI kit combined with flow cytometry.

RESULTSWe identified human SSRP1 as an interacting partner of TgPP2C. The C-terminal region of SSRP1 including the amino acids 471 to 538 was specifically mapped as the region responsible for interaction with TgPP2C. The overexpression of TgPP2C down-regulated cell apoptosis and negatively regulated apoptosis induced by DRB, casein kinase II (CKII) inhibitor, through enhanced interaction with SSRP1.

CONCLUSIONTgPP2C may be a parasitic factor capable of promoting cell survival through interaction with the host protein SSRP1, thereby creating a favorable environment for parasite growth.

Apoptosis ; Blotting, Western ; DNA-Binding Proteins ; genetics ; metabolism ; Flow Cytometry ; HeLa Cells ; High Mobility Group Proteins ; genetics ; metabolism ; Humans ; Immunoprecipitation ; Phosphoprotein Phosphatases ; genetics ; metabolism ; Protein Phosphatase 2C ; Toxoplasma ; enzymology ; Transcriptional Elongation Factors ; genetics ; metabolism ; Two-Hybrid System Techniques