人白细胞硫氧还蛋白还原酶的分子克隆和序列分析

目的：克隆人白细胞硫氧还蛋白还原酶（thioredoxin reductase,TR)编码区的cDNA并进行序列分析。方法：采用RT－PCR方法获得TR基因cDNA，选择阳性克隆并测序。结果：通过分子克隆和序列分析，发现TR基因长1554bp,ORF为1494bp，编码498个氨基酸，结论：确定了中国人白细胞TR的cDNA序列，并据此推导出相应的氨基酸序列。     

Molecular cloning and nucleotide sequence analysis of a novel human papillomavirus (Type 82) associated with vaginal intraepithelial neoplasia

The genome of a novel human papillomavirus (HPV-82) was cloned from a vaginal intraepithelial neoplasia grade I. In our series of 291 biopsy specimens, HPV-82 was identified in one case each of cervical intraepithelial neoplasia grade II and grade III by blot hybridization. The histological localization of HPV-82 DNA in the three lesions was confirmed by in situ hybridization. The results indicated that HPV-82 is an etiologic agent for vaginal and cervical intraepithelial neoplasia. By nucleotide sequence similarity of L1 open reading frame (ORF), HPV-82 was closely related to HPV-26, -51, and -69. To know the precise relationship between the HPVs, we determined the complete sequence of HPV-82, as well as that of HPV-69. Sequencing revealed that the four HPVs had no initiation codon in the E5 ORF and had extensive nucleotide sequence similarities in all ORFs. In addition, they exhibited unique frame position patterns for ORFs, different from those of the other genital HPVs.     

Molecular cloning of human RP105

RP105 is a 105-kDa type I membrane protein of the leucine-rich repeat (LRR) family. Anti-RP105 sensitizes B cells to antigen-receptor-mediated apoptosis, but protects B cells from radiation-induced apoptosis and stimulates B cell proliferation. The sequence of the mouse RP105 has been reported. Here, we report the characterization of the human RP105. The 2.6-kb cDNA encodes a protein of 661 amino acids which displays 78% homology with mouse RP105. The 22 LRR and the 9 potential N-linked glycosylation sites within the extracellular region are conserved. While previous studies have shown that RP105 is expressed on surface IgM⁺IgD⁺⁺ B cells in mice, human RP105 was shown to be expressed on all subsets of mature B cells and dendritic cells. Human RP105 gene was mapped to the long arm of chromosome 5, where numerous cytokines and receptors have been localized.     

Acyl-CoA:dihydroxyacetonephosphate acyltransferase: cloning of the human cDNA and resolution of the molecular basis in rhizomelic chondrodysplasia punctata type 2

Rhizomelic chondrodysplasia punctata (RCDP) is a genetic disorder which is clinically characterized by rhizomelic shortening of the upper extremities, typical dysmorphic facial appearance, congenital contractures and severe growth and mental retardation. Patients with RCDP can be subdivided into three subgroups based on biochemical analyses and complementation studies. The largest subgroup contains patients with mutations in the PEX7 gene encoding the PTS2 receptor. This results in multiple peroxisomal abnormalities which includes a deficiency of acyl-CoA:dihydroxyacetonephosphate acyltransferase (DHAPAT), alkyl-dihydroxyacetonephosphate synthase (alkyl-DHAP synthase), peroxisomal 3-ketoacyl-CoA thiolase and phytanoyl-CoA hydroxylase, although there are differences in the extent of the deficiencies observed. Patients in the two other subgroups have been reported to be either deficient in the activity of DHAPAT (RCDP type 2) or alkyl-DHAP synthase (RCDP type 3) while no other abnormalities could be observed. To examine whether the gene encoding DHAPAT is mutated in patients with RCDP type 2, we determined the N-terminal amino acid sequence of the enzyme isolated from human placenta. Using this sequence as a query, we identified a 2040 bp open reading frame (ORF) in the human database of expressed sequence tags. Expression of this ORF in the yeast Saccharomyces cerevisiae showed that we have identified the DHAPAT cDNA. The deduced amino acid sequence revealed no PTS2 consensus sequence. In contrast DHAPAT appears to contain a putative PTS1 at the extreme C-terminus. All RCDP type 2 patients analyzed were found to contain mutations in their DHAPAT cDNA. This demonstrates that RCDP type 2 is the result of mutations in DHAPAT.      

人白细胞分化抗原CD59基因克隆及序列分析

为了获得人ＣＤ５９ｃＤＮＡ完整序列,以建立表达人ＣＤ５９分子的小鼠Ｔ细胞模型,更深入地探补体ＭＡＣ及ＣＤ５９分子与Ｔ细胞活化的关系。方法通过设计和合成成引物,提取细胞总ＲＡＮ进行逆转录反应,经ＰＣＲ扩增目的片段,并将基克隆于ＰＵＣ１８及ＰＵＣ１９质粒上,测定其ＤＮＡ序列。     

Molecular basis of human dentin diseases

In recent years, substantial progress has been made regarding the molecular etiology of human structural tooth diseases that alter dentin matrix formation. These diseases have been classified into two major groups with subtypes: dentin dysplasia (DD) types I and II and dentinogenesis imperfecta (DGI) types I-III. Genetic linkage studies have identified the critical loci for DD-II, DGI-II, and DGI-II to human chromosome 4q21. Located within the common disease loci for these diseases is cluster of dentin/bone genes that includes osteopontin (OPN), bone sialoprotein (BSP), matrix extracellular phosphoglycoprotein (MEPE), dentin matrix protein 1 (DMP1), and dentin sialophosphoprotein (DSPP). To date, only mutations within dentin sialophosphoprotein have been associated with the pathogenesis of dentin diseases including DGI types-II and -III and DD-II. In this article, we overview the recent literature related to these dentin genetic diseases, their clinical features, and molecular pathogenesis.     

Molecular basis of type I (tryrosinase-related) oculocutaneous albinism: Mutations and polymorphisms of the human tyrosinase gene

Type I (tyrosinase related) oculocutaneous albinism (OCA) results from mutations of the tyrosinase gene on chromosome 11q that lead to reduced or absent melanin pigment synthesis. The phenotype of Type I OCA is broad, ranging from a total lack to only a moderate reduction of melanin, and the phenotypic variation is associated with different mutant alleles at the tyrosinase locus. A total of 36 mutations have been identified in Type I OCA including 24 missense, 4 nonsense, and 8 frameshift mutations. The majority of affected individuals have been compound heterozygotes with different maternal and paternal alleles. Six polymorphic sites for haplotype analysis have been identified in the tyrosinase gene including 2 in the promoter region, 2 in the coding region associated with alternative amino acids in the protein, and 2 RFLPs in the first intron. © 1993 Wiley-Liss, Inc.     

Molecular cloning and sequencing of feline CD56 (N-CAM)

We isolated feline CD56 cDNA to investigate the primary structure of CD56 of feline leukocytes. Sequencing analysis revealed that an open reading frame (2538 bp) encoded a homologue of a 140-kDa isoform of CD56. The predicted amino acid sequence showed 97.3% homology with that of humans.     

Molecular cloning of a novel human papillomarvirus (type 58) from an invasive cervical carcinoma

A novel human papillomavirus type (HPV) was cloned from an invasive cervical carcinoma. The viral clone showed no homology with other known prototypes of HPV (HPV-1 through HPV-57), except HPV-33 by Southern blot analysis under stringent conditions. It showed less than 20% homology to HPV-33 by reassociation kinetic analysis. The restriction endonuclease map of the clone was different from those of other HPV types and its predicted genome organization surmised by hybridization with subgenomic fragment probes of HPV-33 DNA showed the typical HPV genome organization. The results indicate that this clone is a new type of HPV, designated as HPV-58, distinct from the other known types of HPV. HPV-58 was detected in none of 6 specimens of cervical condylomata acuminata, in 7 of 58 specimens of cervical intraepithelial neoplasia, and in 4 of 50 specimens of invasive cervical carcinoma studied in Nagano prefecture, Japan.