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PubMed2001

Comparison of the deduced amino acid sequence of guinea pig adenovirus hexon protein with that of other mastadenoviruses.

PURPOSE: We sought to isolate, clone, and determine the nucleic acid sequence of the guinea pig adenovirus (GPAdV) hexon gene. From this, the amino acid sequence of the cloned portion was deduced and compared with a set of mastadenovirus hexons. METHODS: The DNA isolated from a histologic section of infected guinea pig lung was subjected to high-fidelity amplification, using degenerate primers complementary to a conserved nucleic acid sequence near the 3' end of the hexon gene of mastadenoviruses and a 5' primer from GenBank accession No. X95630 (GPAdV hexon gene partial sequence). The amplified product was cloned, the nucleic acid sequence was determined, and the amino acid sequence was deduced and compared with the hexon amino acid sequences of 25 mastadenoviruses. RESULTS: The cloned fragment comprised 1,603 base pairs (bp) [approximately 50%]) of the hexon. Of the initial 278 nucleic acids of the clone, 276 were identical with GenBank accession No. X95630, and the deduced amino acid sequences of both were identical. The deduced GPAdV hexon amino acid sequence from the clone aligned with structural regions NT, V1, DE1, and FG1 described for human adenovirus types 2 and 5. The GPAdV hexon had < 50% similarity in amino acid sequence, compared with hexons of 25 other mastadenoviruses. Analysis of regional peptide similarities revealed the GPAdV hexon to be more similar to animal mastadenoviruses and human subgroups A, C and F than to other human subgroups. CONCLUSIONS: The cloned portion of the GPAdV hexon contained a sequence nearly identical to that of GenBank accession No. X95630. Compared with the truncated amino acid sequences of human adenovirus types 2 and 5, the deduced GPAdV hexon amino acid sequence was similar in areas structurally conserved, but different in areas associated with type-specific antigenicity.

Adenoviridae Infections↗
PubMed2002

[Rapid identification of human testis spermatocyte apoptosis-related gene, TSARG2, by nested PCR and draft human genome searching].

Cloning apoptosis-related novel genes is a key to further understanding of apoptosis mechanism and the biology process of germ cells, and is of momentous significance on clarifying physiological and pathological process of spermatogenesis. To rapidly attain human novel gene full-length cDNA sequence, the gene-specific primers and the vector-specific primers were designed for nested PCR, and draft human genome searching was performed to rapidly identify the TSARG2 (GenBank accession number AY040204) 5' end from a human testis cDNA library, by using a cDNA fragment (GenBank accession number BE644542) as an electronic probe, which was significantly changed in cryptorchidism and represented a novel gene. Furthermore, a mouse homologue of this gene was identified (GenBank accession number AF395083) by lab on-line. TSARG2 with a 1 233 bp length was composed of 6 exons and spanned about 115 kb of genomic DNA, The putative protein encoded by this gene was 305 amino acid with a theoretical molecular weight of 34 751 dalton and did not share significant homology with any known protein in databases. TSARG2 was expressed in many tissues and mapped to chromosome 4q33-34.1 by database analyses. Therefore, we propose that nested-PCR and draft human genome searching are rapid, sensitive, accurate and efficient method for isolating gene 5' end, even full-length gene from cDNA library.

Amino Acid Sequence↗
PubMed2002

[Molecular cloning and analysis of bovine prolactin full-long genomic as well as cDNA sequences].

In this report, a full-length sequence of bovine prolactin (bPRL) genomic DNA with 9388 bp, which has been accepted by GenBank (Accession Number: AF426315), was firstly cloned by Long PCR procedures. This sequence consists of 5 exons, 4 introns, 854 bp of 5' upstream regulatory region and 69 bp of 3' UTR. Accession number of protein encoded by AF426315 sequence in GenBank is AAL28075 that is composed of 229 amino acid residues, in which signal sequence resides in 1-30 sites and mature polypeptide consists of 199 amino acid residues. The recombinant plasmid containing bPRL genomic DNA was then transfected into eukaryotic cells (COS-7), followed by RT-PCR procedure. An 804 bp of bPRL cDNA containing all the encoding region was obtained, indicating that the bPRL genomic DNA reported herein had its biological function at the transcriptional level. Results derived from information searching by Blast program revealed that there were various SNP sites in the sequences of bPRL mRNAs and ESTs collected in GenBank, which located mainly in downstream encoding region and 3' UTR. These SNP sites did not alter the related amino acids encoded. In addition, mRNA sequences encoding 5' signal sequence of bPRL gene was highly conserve.

Animals↗
PubMed2003

[Cloning and tissue expression analysis of up-regulated cDNA fragment in human gastric cancer].

OBJECTIVE: To identify novel human gastric cancer-associated susceptibility gene for early diagnosis and treatment of gastric cancer. METHODS: A primer was designed for 3'-rapid amplification of cDNA end(RACE) and amplified fragments were cloned, then they were analyzed by sequencing. Compared with ESTs in Genbank, the EST fragment represented a novel gene. Combination of Northern blot and virtual Northern and multiple tissues Northern blot, expression of the cDNA in multiple normal and carcinoma tissues were analyzed. RESULTS: One of the important cDNA bands with poly(A) tail was cloned. This band was named W41. Sequence analysis showed that W41 consists of 533 bp. Basic local alignment search tool analysis revealed that W41 has low identity with any genes from GenBank. This sequence data was submitted to GenBank with accession No. AF 325202. Northern blot revealed that W41 presented higher expression in gastric cancer tissue than in normal tissue. Multiple tissue Northern blot revealed that W41 presented higher expression in multiple cancers than in normal tissues. Virtual Northern revealed that the cDNA presented higher expression in tumor series analysis of gene expression libraries than in normal. CONCLUSION: A novel human gastric cancer-associated cDNA fragment was identified.

Blotting, Northern↗
PubMed2003

[Cloning, sequencing and bioinformatics analysis of a new tumor suppressor gene ndr2 from mouse].

BACKGROUND & OBJECTIVE: Ndr2 (N-myc down stream regulator) gene in human is a new gene cloned with the human adult whole brain cDNA as template in 1999, which accession number is AF159092 in GenBank. Locating backward position of the N-myc gene in human chromosome, this gene was named Ndr2 gene. The previous experimental results showed Ndr2 gene probably is a tumor suppressor gene. To research the function of Ndr2 gene, the authors cloned the genomic sequence of ndr2 from mouse. METHODS: To clone Ndr2 genomic sequence by reverse transcription-polymerase chain reaction(RT-PCR) with the mouse genome library as template; automatic sequencing was performed using 310 Genetic Analyzer; homogeneous analysis was made using GenBank BLAST; open reading fragment(ORF) analysis was made using PC Gene and ORF Finder; domain analysis was made using ProDom system. RESULTS: A fragment (about 3310bp,identified by agarose gel electrophoresis) was obtained using RT-PCR with the mouse genome library as template. The fragment was cloned in pMD18-T vector. BLAST analysis showed that the sequence was highly homogeneous (with the homogeneity rate of 91.4%) with Ndr2 gene in human and non-homogeneous with genomic sequence database in mouse. ORF analysis showed that there was a complete coding region in it, which including 8 extrons and 7 introns; it can interpret a protein containing about 200 amino acid residuals. ProDom analysis showed there was a domain like acyl carrier protein(ACP) in it. CONCLUSION: The authors cloned Ndr2 gene in mouse and proved that the sequence is a new genome sequence in mouse genomic sequence database. At present, the genome sequence has been submitted to GenBank(the accession number: AY151387).

Adaptor Proteins, Signal Transducing↗
PubMed2003

[Molecular cloning of TSARG3 gene related to apoptosis in human spermatogenic cells].

OBJECTIVE: To clone a novel gene which is related to human testis spermatogenesis apoptosis. METHODS: To rapidly attain human novel gene full-length cDNA sequence from a human testis cDNA library,the gene-specific primers and the vector-specific primers were designed for nested polymerase chain reaction. Sequencing was performed and the result was analysed. RESULTS: The present authors discovered the TSARG3 gene(GenBank accession number AF419291) from a human testis cDNA library, using a cDNA fragment (GenBank accession number BE644537) as an electronic probe, which was significantly changed in cryptorchidism and represented a novel gene. Furthermore, a mouse homologue of this gene was identified (GenBank accession number AF419292) by using the same method. CONCLUSION: A novel gene named TSARG3 was cloned. It is considered that the function of the new gene is related to human testis spermatogenesis apoptosis.

Amino Acid Sequence↗
PubMed2003

[Cloning and sequencing of ACC oxidase gene from sugarcane].

The plant hormone ethylene is not only responsible for the initiation of fruit ripening, senescence and dormancy but also for regulating many other plant developmental processes, such as seed germination, root initiation, growth, floral differentiation, sex differentiation and responding to environment stresses. One of the rate-limiting steps for ethylene biosynthesizing in plant is catalyzed by 1-aminocyclopropane-1-carboxylate (ACC) oxidase. Understanding of ethylene expressive pattern in plant is an entrance to understand the roles of ethylene on plant. In this paper, two degenerate oligonucleotide primers were designed, coding for two conservative amino acid regions in ACC oxidase protein family, the sequences of the two primers were TAGAGCTCGATGC[TA]TG [CT]GA[GA]AA[AC]TGGGG and CGTCTAGAGCTTC[GA]AATCTTGGCTCCTT respectively. A PCR amplification was performed on sugarcane (Saccharum L. Hybrid cv. ROC16) DNA template, and produced a fragment of 940 bp. By using the program of BLAST on NCBI GenBank database, the sequence presented a very high match with the ACC oxidase genes from other plants, 63 searched out sequences were all ACC oxidase genes. After alignment on PCgene program, the identities of the cloned fragment with ACC oxidase genes from rice and bamboo were both reaching about 88%. So we can concluded that the cloned sequence was a member of ACC oxidase genes fragment from sugarcane. The sequence has been submitted to the GenBank database, the accession number is AF442821. According to the ACC oxidase protein family, a 'intron' of 103 bp was excluded and the sequence coded 279 amino acids, which spanned 88% of the putative whole sequence in length. Alignment and phylogenetic analysis of the amino acid sequence deduced from this fragment and the ACC oxidase sequences of other plants retrieved from GenBank were carried out by using PCgene program. The putative amino acid sequence shared a homology of 86% with the ACC oxidases of bamboo and rice, 74.6% with banana, 70% with tomato and potato and 68% with melon and carnation, which showed that the homology of sugarcane ACC oxidase with monocot was higher than with dicot. The results of phylogenetic analysis showed that ACC oxidase from sugarcane and ACC oxidases from rice clustered together firstly, and then came those from banana, ACC oxidases of dicot from potato, tomato, petunia, melon, Arabidopsis thaliana and carnation came subsequently. It indicated that sugarcane ACC oxidase had a closer phylogenetic affinities to the monocot ACC oxidase sequences than to the dicot ACC oxidases sequences. The clustering results of ACC oxidase molecules accorded with morphological classification system.

Amino Acid Oxidoreductases↗
PubMed2003

Severe acute respiratory syndrome-associated coronavirus genotype and its characterization.

OBJECTIVE: To study the severe acute respiratory syndrome (SARS)-associated coronavirus genotype and its characteristics. METHODS: A SARS-associated coronavirus isolate named ZJ01 was obtained from throat swab samples taken from a patient in Hangzhou, Zhejing province. The complete genome sequence of ZJ01 consisted of 29,715 bp (GenBank accession: AY297028, version: gi: 30910859). Seventeen SARS-associated coronavirus genome sequences in GenBank were compared to analyze the common sequence variations and the probability of co-occurrence of multiple polymorphisms or mutations. Phylogenetic analysis of those sequences was done. RESULTS: By bioinformatics processing and analysis, the 5 loci nucleotides at ZJ01 genome were found being T, T, G, T and T, respectively. Compared with other SARS-associated coronavirus genomes in the GenBank database, an A/G mutation was detected besides the other 4 mutation loci (C:G:C:C/T:T:T:T) involved in this genetic signature. Therefore a new definition was put forward according to the 5 mutation loci. SARS-associated coronavirus strains would be grouped into two genotypes (C:G:A:C:C/T:T:G:T:T), and abbreviated as SARS coronavirus C genotype and T genotype. On the basis of this new definition, the ZJ01 isolate belongs to SARS-associated coronavirus T genotype, first discovered and reported in mainland China. Phylogenetic analysis of the spike protein gene fragments of these SARS-associated coronavirus strains showed that the GZ01 isolate was phylogenetically distinct from other isolates, and compared with groups F1 and F2 of the T genotype, the isolates of BJ01 and CUHK-W1 were more closely related to the GZ01 isolate. It was interesting to find that two (A/G and C/T) of the five mutation loci occurred in the spike protein gene, which caused changes of Asp to Gly and Thr to Ile in the protein, respectively. CONCLUSION: Attention should be paid to whether these genotype and mutation patterns are related to the virus's biological activities,epidemic characteristics and host clinical symptoms.

Genotype↗
PubMed2004

[Study on the molecular epidemiology of beta-lactamase TEM gene in isolated Streptococcus pneumoniae].

OBJECTIVE: To investigate the beta-lactamase TEM gene of isolated Streptococcus pneumoniae (Sp) in Suzhou area. METHODS: Twenty-three strains of Sp were collected from respiratory tract secretions of children with respiratory diseases in Nov 2002 to Apr 2003 at Children's Hospital of Suzhou University (reference strain ATCC49619) to build TEM polymerase chain reaction (PCR) system (reference strain E. coli. 9-j53R1 with TEM gene) TEM gene of 23 strains was detected to comparo the sequences with published TEM gene sequences in GenBank for analyzing TEM gene model. RESULTS: Twenty-one strains had TEM gene with a positive rate of 91.3% (21/23). TEM-129 gene were confirmed from No.17 (SR017, penicillin resistance) TEM sequence. New discovered TEM-129 sequence had a modification (ATG[M]-->ATA[I]) at No.182 code and published (GenBank: www.ncbi.nlm.nih.gov/nucleotide, AY452662). TEM-1 genes were confirmed from other TEM sequences. New discovered TEM-1 gene of isolated Sp had been published (GenBank: www.ncbi.nlm.nih.gov/nucleotide, AY392531) too. CONCLUSION: Isolated Sp had TEM gene (TEM-129, EM-1 genotype) with a positive rate of 91.3%. The result enriched the understanding of isolated Sp with penicillin resistance.

Base Sequence↗
PubMed2004

[Molecular cloning of a protein antigen gene of Cysticercus cellulosae].

OBJECTIVE: To immunoscreen one protein antigen gene from a cDNA library of Cysticercus cellulosae. METHODS: A eDNA library of C. cellulosae was constructed after cDNA was synthesized, and immunoscreened using rabbit anti-C. cellulosae polyclone antibody. The gene structure and its possible function were analyzed by comparing with the sequences available in the GenBank, after the insert of positive clone was subcloned to pBluescript SK plasmid and the nucleotide sequence of the cDNA was determined by dideoxynucleotide chain termination method using a Taq DyeDeoxy Terminator Cycle Sequencing Kit. The amino acid sequence was deduced from nucleotide sequence using GENETYX software. Homological search of the nucleotide sequences was done using BLAST in GenBank. RESULTS AND CONCLUSION: A cDNA clone of 1320 bp was isolated. The clone contained one open reading frame composed of 1260 bp encoding 420 amino acids, in which two potential glycosylation sites were found. The partial nucleotide sequence of the gene fragment showed high homology with the essential spectrin gene of Caenorhabditis elegans and the erythrocyte surface antigen gene of Plasmodium falciparum, when the gene fragment was homologically analyzed in GenBank.

Amino Acid Sequence↗
PubMed2005

[Acquisition and analysis of 149 ESTs and 18 novel genes of Schistosoma japonicum].

OBJECTIVE: To acquire and analyze adult stage Schistosoma japonicum (Chinese strain) expressed sequence tags and new genes from an adult S. japonicum cDNA library, and to search new vaccine candidates and drug targets. METHODS: A cDNA library was constructed from adult stage S. japonicum. Clones were selected randomly from the cDNA library and were sequenced. ESTs and new genes were acquired after analysis in GenBank databases by BLAST and other programs. All ESTs and new genes were submitted to GenBank and received accession numbers. RESULTS: 149 ESTs were acquired from a total 382 clones that were randomly selected from the adult S. japonicum cDNA library. All ESTs were successfully submitted to the dbEST at Genbank. Some of them were homologous with sequences of male, female, egg, schistosomula, cercaria and miracidia of S. japonicum. 18 new genes of adult S. japonicum were acquired. Some genes were housekeeping genes and some genes might be interesting as vaccine candidates or drugs targets. CONCLUSIONS: The EST strategy is a rapid, efficient and economical method to acquire ESTs and to discover new genes of adult stage S. japonicum from cDNA libraries.

Animals↗
PubMed2004

[Construction of cDNA library from NPC tissue and screening of antigenic genes].

To obtain the NPC-associated antigens, a powerful new method, SEREX (serological identification of antigen by recombinant cDNA expression library), was used for identifying the antigens eliciting humoral immune response. Before performing serological analysis, a high quality cDNA library derived from human nasopharyngeal carcinoma (NPC) tissue was constructed. The primary library consisted of 3.64 x 10(6) recombinants and the recombinant rate was 94%. For better preserving the cDNA library, it was amplified. As a result, the titer of the amplified cDNA library was 3.8 x 10(9) pfu/mL. With SEREX method, immunoscreening for the detection of reactive clones in the human NPC tissue cDNA library was performed with autologous serum. As a result, 23 positive clones encoding antigenic genes were obtained after immunoscreening, and the nucleotide sequences of cDNA inserts were determined and analyzed with BLAST software in GenBank. Results showed that the 23 reactive clones were derived from 16 different genes. 10 of 16 genes had high homologous to the genes known in GenBank, such as RPL31, S100 A2, MT2A, etc. However, there were also 6 genes with low homology to the genes known in GenBank. Furthermore, 3 of 6 genes may be novel genes. The associations of these genes to NPC and the roles that they played in the occurrence and development of NPC should be revealed by further research.

Antigens, Neoplasm↗
PubMed2005

[Molecular cloning of full-long cDNA sequences encoding hairless gene in the Kunming mouse].

The mouse hairless gene is a crucial nuclear receptor gene associated with the structure of hair and skin. It encodes a putative zinc finger transcription factor, and is a transcriptional corepressor for thyroid hormone receptors. Hairless gene plays a critical role in maintaining the delicate balance between cell proliferation, differentiation, and apoptosis in the hair follicle as well as in the interfollicular epidermis, and is concerned with the control of hair growth cycling. This study was designed to clone and analyze the cDNA encoding Hr from Kunming mouse. The RT-PCR method was developed to clone the Hr cDNA. A full-length cDNA and CDS sequences of Kunming mouse were 4104bp and 3546bp, respectively, which has been accepted by GenBank (Accession Number: AY547391). Accession number of protein encoded by AY547391 sequence in GenBank is AAT45233 , composed of 1181 amino acid residues. The Hr cDNA of Kunming mouse was cloned and sequenced for the first time. The identities of CDS of Hr gene were 99.9%, 94.4%, 83.1%, 78.1%, 81.9% and 82.1% by homologous comparison among Kunming mouse and other six species, and that were 99.9%, 92.2%, 81.7%, 70.8%, 79.9% and 80.1% respectively in amino acid sequences. The results suggested a high degree of conservation and thus functional significance of the Hr gene among different mammalian taxons. The results derived from information searching by Blast program revealed that there were 4 SNP sites and one deletion mutation in the sequences of hairless gene mRNAs between Kunming mice and that collected in GenBank. Three SNP sites did not alter the related amino acids encoded. Two SNP proved to be polymorphism mutant sites with amino acids changes. The results provided new data for SNPs in Hr gene.

Amino Acid Sequence↗
PubMed2006

Construction of cDNA library from NPC tissue and screening of antigenic genes.

To construct cDNA library of nasopharyngeal carcinoma (NPC) and obtain the NPC associated or specific antigens from it, we used a powerful new method to identify the antigens eliciting humoral immune response, which is SEREX (serological identification of antigen by recombinant cDNA expression library). Autologous serum of NPC patient was used to screen the reactive clones in the human NPC tissue cDNA library consisted of 3.64 million recombinants. The 23 exact positive clones were subcloned to monoclonality and the size of cDNA inserts was identified by PCR. Then the nucleotide sequence of cDNA inserts was determined, and the sequence alignments were performed with BLAST software on GenBank database. They represented 16 different antigens. A detailed sequence analysis showed that 10 of 16 genes were high homologous to genes known in GenBank, such as RPL31, S100 A2, MT2A, etc. However, there were also 6 genes with low homology to genes in GenBank. Furthermore, 3 of 6 genes may be novel genes. The associations of these genes to NPC and the roles that they played in the occurrence and development of NPC should be further revealed.

Antigens, Neoplasm↗
PubMed2006

[Cloning and analysis of gene encoding wheat translation initiation factor, eIF5A].

Eukaryotic translation initiation factor 5A (eIF5A) is involved in cell proliferation, senescence, development and environmental response. In this paper, DNA and cDNA of Chinese Spring was amplified by PCR with special primers, two special fragments of 1 679 bp and 1 910 bp were obtained with DNA as template and one special fragment of 636 bp was yielded with cDNA as template. Which were named eIF5a1 (GenBank number: DQ167202), eIF5a2 (Genbank number: DQ167201) and eIF5a3, respectively. The complete sequence (768 bp) of eIF5a3 (Genbank number: DQ167203) was obtained using GeneRacer kit. Nucleotide sequence analysis shows that eIF5a1 and eIF5a2 share identical transcriptions of 636bp which have only 6 nucleotides difference. Putative amino acid sequences analysis revealed that there was only one or two amino acid difference in eIF5a1, eIF5a2 and eIF5a3. Phylogenic analysis indicated that the eIF5A of wheat were relation to corn, rice, tomato and potato closely. In additional, eIF5a2 is located on chromosome 2B using Langdon D-genomic disomic substitution lines and the expression of eIF5A was also investigated by Semi-quantitative PCR.

Amino Acid Sequence↗
PubMed2006

[Cloning, expression and identification of catalase of Helicobacter pylori].

AIM: To construct the recombinant plasmid containing catalase (KatA) of Helicobacter pylori (Hp), analyze its nucleic acid sequence, express it in E. coli and study its antigenicity. METHODS: KatA fragments were amplified from Hp chromosomal DNA by PCR. Its T-A was cloned, sequenced and compared with other HP strains on the GenBank. Then the gene cloned into pGEX-4T-1 fusion expression vector was expressed in E. coli and purified by GST-affinity chromatography. The purified product was used to identify 29 stains of mouse anti Hp monoclonal antibodies and analyze antigenicity with serum of Hp-infected patients by Western blot. RESULTS: KatA fragments were composed of 1,515 bp (GenBank No. DQ333889) and the nucleotide homology with other Hp strains on the GenBank was 96%-97%. 85 kDa of the recombinant KatA-pGEX-4T-1 was expressed in E. coli. 4 of 29 anti-Hp mouse monoclonal antibodies were against KatA. Western blot analysis proved that KatA was specifically recognized in the serum of Hp-infected patients. CONCLUSION: The recombinant KatA has original antigenicity. It is of great value to clinical sero-diagnosis and vaccine study of Hp.

Antibodies, Monoclonal↗
PubMed2006

[Study on the molecular background of Del phenotype in Chinese population].

OBJECTIVE: To elucidate the molecular background of Del phenotype in the Chinese population and explore new Del alleles. METHODS: Five hundred and fifteen RhD negative blood samples was tested by Rh typing test, indirect antiglobulin test and adsorption and elution assay to screen the Del phenotype. DNA of all the Del samples was analysed by multiplex polymerase chain reaction (MPX PCR) for the presence of RHD and by sequence-specific primer polymerase chain reaction (PCR-SSP) for Del alleles: RHD 1227A and RHD 885T. Samples which showed the negative result by PCR-SSP, were additionally analysed by genomic DNA sequencing and cDNA sequencing. RESULTS: Seventy-nine Del samples were found by adsorption and elution assay. All these samples had RHD exons 3, 4, 5, 6, 7 and 9. Except 4 Del samples, other 75 Del samples carried the RHD 1227A allele. None of the samples had the RHD 885T allele. Four novel RHD alleles were found in these four Del sample. There were RHD 3G-->A (GenBank DQ310735), RHD 28C-->T, RHD 53T-->C (GenBank DQ451877,DQ451878), RHD 251T-->C (GenBank DQ310734). CONCLUSION: fnRh blood group system is very complex. New D variation phenotypes and new RHD alleles may be discovered ceaselessly.

Alleles↗
PubMed2006

Screening of genes for proteins interacting with the PS1TP5 protein of hepatitis B virus: probing a human leukocyte cDNA library using the yeast two-hybrid system.

BACKGROUND: The hepatitis B virus (HBV) genome includes S, C, P and X regions. The S region is divided into four subregions of pre-pre-S, pre-S1, pre-S2 and S. PS1TP5 (human gene 5 transactivated by pre-S1 protein of HBV) is a novel target gene transactivated by the pre-S1 protein that has been screened with a suppression subtractive hybridization technique in our laboratory (GenBank accession: AY427953). In order to investigate the biological function of the PS1TP5 protein, we performed a yeast two-hybrid system 3 to screen proteins from a human leukocyte cDNA library interacting with the PS1TP5 protein. METHODS: The reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify the gene of PS1TP5 from the mRNA of HepG2 cells and the gene was then cloned into the pGEM-T vector. After being sequenced and analyzed with Vector NTI 9.1 and NCBI BLAST software, the target gene of PS1TP5 was cut from the pGEM-T vector and cloned into a yeast expression plasmid pGBKT7, then "bait" plasmid pGBKT7-PS1TP5 was transformed into the yeast strain AH109. The yeast protein was isolated and analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting hybridization. After expression of the pGBKT7-PS1TP5 fusion protein in the AH109 yeast strain was accomplished, a yeast two-hybrid screening was performed by mating AH109 with Y187 containing a leukocyte cDNA library plasmid. The mated yeast was plated on quadruple dropout medium and assayed for alpha-gal activity. The interaction between the PS1TP5 protein and the proteins obtained from positive colonies was further confirmed by repeating the yeast two-hybrid screen. After extracting and sequencing of plasmids from blue colonies we carried out a bioinformatic analysis. RESULTS: Forty true positive colonies were selected and sequenced, full length sequences were obtained and we searched for homologous DNA sequences from GenBank. Among the 40 positive colonies, 23 coding genes with known functions were obtained, including Homo sapien leukocyte adhesion protein p150, 95, interleukin 2 receptor gamma chain, PALM2-AKAP2 protein (PALM2-AKAP2), eukaryotic translation initiation factor 4A, beta-2-microglobin, solute carrier family 9 (sodium/hydrogen exchanger), calreticulin, asialoglycoprotein receptor 1 (ASGR1), MHC class II lymphocyte antigen, cytochrome c oxidase subunit 1, lymphocyte antigen 86 (LY86) and lymphocyte cytosolic protein 1. One novel gene with unknown function was found and named as PS1TP5BP1. After being electronically spliced, it was deposited in GenBank (accession number: DQ471327). CONCLUSIONS: Genes of proteins interacting with PS1TP5 were successfully screened from leukocyte cDNA library. These results suggested that PS1TP5 was closely correlated with immunoregulation, carbohydrate metabolism, signal transduction, the formation of hepatic fibrosis and initiation and development of tumors and also brought some new clues for further studying the biological functions of the pre-S1 protein.

Amino Acid Sequence↗