Cloning and characterization of ovine immunoglobulin G Fc receptor III (FcγRIII).
Receptors for the Fc regions of immunoglobin G (IgG) play a critical role in immunoregulation and immune defenses against pathogens. In this study, we describe the cloning, eukaryotic expression and IgG subclass specificity of ovine Fc gamma receptor III (FcγRIII). The newly cloned ovine FcγRIII cDNA contains a 940 bp open-reading frame (ORF), and is predicted to encode a 250 amino acid transmembrane glycoprotein composed of two immunoglobulin-like extracellular domains, a transmembrane region and a short cytoplasmic tail. The overall identity of the ovine FcγRIII amino acid sequence to its cattle, pig and human counterparts was 83.2%, 62.0%, 60.7%, respectively. Overlapping PCR was performed with the extracellular domain of ovine FcγRIII and the transmembrane and intracellular region of ovine Fc gamma chain to construct a chimeric receptor. Rosetting analysis showed that transfected COS-7 cells required Fc receptor gamma chain for the expression of FcγRIII on the surface. COS-7 cells expressing FcγRIII were able to bind chicken erythrocytes sensitized with ovine IgG1, but not IgG2. Identification of ovine FcγRIII will further our understanding of the ovine immune system.
College of Pharmacy Science and Technology, Tianjin University, Tianjin 300072, PR China.
Yunchao
Y
Liu
Songlin
S
Qiao
Aiping
A
Wang
Junbiao
J
Chang
Yumei
Y
Chen
Suzhen
S
Yang
Ruiguang
R
Deng
Gaiping
G
Zhang
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002645:Chickens; D002522:Chlorocebus aethiops; D004912:Erythrocytes / Q000276:immunology; D005786:Gene Expression Regulation / Q000502:physiology; D007074:Immunoglobulin G / Q000378:metabolism; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D017452:Receptors, IgG / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins; D012756:Sheep / Q000378:metabolism*
D007074:Immunoglobulin G; D017452:Receptors, IgG; D011994:Recombinant Proteins