title: Molecular cloning and characterization of the full-length cDNA encoding the porcine CD28.
abstract: CD28 is one of the most important co-stimulatory molecules required for effective activation of resting T cells in human and mouse. However, there are few studies on porcine CD28 (pCD28) until now. In the present study, we cloned and characterized the full-length cDNA of CD28 from the miniature pig. The open reading frame (ORF) sequence of pCD28 gene was organized into four exons, which were predicted to be in correspondence with the signal sequence, immunoglobulin variable-like (IgV) domain, transmembrane domain and cytoplasmic tail, respectively. We also identified the putative ligand binding site of CD28 within the IgV domain and the consensus motifs (one "YMNM" motif and two proline-rich motifs) within the cytoplasmic domain. Porcine CD28 was confirmed to be expressed on the cell membrane as indicated by indirect immunofluorescence assay (IFA). The putative promoter region of pCD28 was also cloned by the modified nested PCR and the cloned region could successfully drive the expression of yellow fluorescent protein (YFP) expression in porcine peripheral blood mononuclear cells (PBMCs). The present study is the first report of cloning and characterization of CD28 in porcine. Our work provided fundamental information for further researches on the structure and function of CD28 in porcine.
authors.affiliation: National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Huali
authors.initials: H
authors.lastname: Su
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhao
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Huang
authors.forename: Xianyong
authors.initials: X
authors.lastname: Liu
authors.forename: Xun
authors.initials: X
authors.lastname: Suo
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D018106:CD28 Antigens / Q000235:genetics* / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics* / Q000276:immunology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D012313:RNA / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D013552:Swine; D013556:Swine, Miniature / Q000235:genetics* / Q000276:immunology
chemical_list: D018106:CD28 Antigens; D018076:DNA, Complementary; D012313:RNA