Cloning and characterization of ovine immunoglobulin G Fc receptor II (FcgammaRII).
Immunoglobulin G (IgG) Fc receptors (FcgammaRs) bind to immune complexes through interactions with the Fc region of IgG to initiate or inhibit the defense mechanism of the leukocytes on which they are expressed. In this study, we describe the cloning, sequencing and characterization of ovine FcgammaRII. By screening a translated expression sequence tag (EST) database with the protein sequence of bovine IgG Fc receptor II, we identified a putative ovine homologue. Using rapid amplification of cDNA ends (RACE), we isolated the cDNA encoding ovine FcgammaRII from peripheral blood leucocyte RNA. The ovine FcgammaRII cDNA contains an 894bp open-reading frame, encoding a 297 amino acid transmembrane glycoprotein composed of two immunoglobulin-like extracellular domains, a transmembrane region and a cytoplasmic tail with an immunoreceptor tyrosine-based inhibitory motif (ITIM). The glycoprotein encoded by the cloned cDNA was then expressed on the surface of COS-7 cells and immunoglobulin-binding assays show that it binds ovine IgG1, but not IgG2. Identification of the ovine FcgammaRII will aid in the understanding of the molecular basis of IgG-FcgammaR interaction.
Liu
Yunchao
Y
Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China.
Wang
Aiping
A
Qiao
Songlin
S
Zhang
Gaiping
G
Xi
Jun
J
You
Leiming
L
Tian
Xiaohui
X
Li
Qiaomu
Q
Zhang
Lina
L
Guo
Junqing
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002417:Cattle; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D030541:Databases, Genetic; D020224:Expressed Sequence Tags; D015870:Gene Expression; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017452:Receptors, IgG / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012756:Sheep / Q000235:genetics* / Q000276:immunology*; D013045:Species Specificity; D014162:Transfection
D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D017452:Receptors, IgG; D011994:Recombinant Proteins