title: Molecular cloning and expression of the porcine high-affinity immunoglobulin G Fc receptor (FcgammaRI).
abstract: Receptors for the Fc region (FcgammaRs) of immunoglobulin G (IgG) play a crucial role in the immune system and host protection against infection. In this study, we describe the cloning, sequencing, and expression of the high-affinity IgG receptor from pig. By screening a translated Expressed Sequence Tags database with the human FcgammaRI (CD64) protein sequence, we identified a putative porcine homologue. Subsequent polymerase chain reaction amplification confirmed that the identified full-length cDNA was expressed in porcine cells. Rosetting analysis shows that COS-7 cells transfected with a plasmid containing the cloned cDNA were able to bind chicken erythrocytes sensitized with porcine IgG. Scatchard analysis indicated that monomeric IgG bound to transiently transfected cells with an affinity of approximately 4x10(7) M(-1). The porcine FcgammaRI cDNA is 1,038 nucleotides long and is predicted to encode a 346-amino-acid transmembrane glycoprotein composed of three Ig-like domains, a transmembrane region, and a short cytoplasmic tail. The overall identity of the porcine FcgammaRI to its human and mouse counterparts at the level of the amino acid sequence was 75% and 57%, respectively. Identification of porcine FcgammaRI will aid in the understanding of the molecular basis of the porcine immune system and further studies of the receptor function.
authors.affiliation: College of Animal and Veterinary Sciences, Henan Institute of Science and Technology, Xinxiang, China.
authors.forename: Gaiping
authors.initials: G
authors.lastname: Zhang
authors.forename: Songlin
authors.initials: S
authors.lastname: Qiao
authors.forename: Qingmei
authors.initials: Q
authors.lastname: Li
authors.forename: Xuannian
authors.initials: X
authors.lastname: Wang
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Duan
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Xiao
authors.forename: Chun
authors.initials: C
authors.lastname: Xia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D017452:Receptors, IgG / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D012397:Rosette Formation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013552:Swine / Q000235:genetics* / Q000276:immunology*; D014162:Transfection
chemical_list: D018076:DNA, Complementary; D017452:Receptors, IgG