Cloning of the chicken immunoglobulin joining (J)-chain gene and characterization of its promoter region.
Three overlapping genomic clones of the chicken immunoglobulin joining (J) chain were isolated and then characterized using restriction enzyme analysis, Southern blot analysis with cDNA probes, and DNA sequencing. The gene consisted of four exons separated by a 2.6-kb intron 1, a 0.9-kb intron 2, and a 0.5-kb intron 3. A transcriptional initiation site was identified by a primer extension method using mRNA and cDNA, indicating that exon 1 was 86 bp encoding 20 amino acid residues. A TATA box was positioned at 29 approximately 25 bp upstream of exon 1. Exons, 2, and 3 consisted of 133 bp and 81 bp, encoding 43 and 26 amino acid residues of the mature protein, respectively. Exon 4 consisted of 202 bp encoding 66 amino acid residues and 1.2 kb of untranslated sequence. Deletion mutants of a 4.1-kb genomic fragment containing exon 1 showed high levels of promoter activities when examined in luciferase reporter assays following transfection into the DT-40 chicken B-cell line. These results suggest that the chicken J-chain gene consists of four exons and three introns and that the transcriptional regulatory elements may be present within 3.8 kb upstream of exon 1.
Takahashi
Tomihisa
T
Department of Pathology, Nihon University School of Dentistry, Tokyo, Japan. takahashi-tm@dent.nihon-u.ac.jp
Kimura
Masayo
M
Matsumoto
Naoyuki
N
Iwata
Arihiro
A
Ogura
Yoshitaka
Y
Yoshida
Toshiyuki
T
Kamei
Nobuhiro
N
Komiyama
Kazuo
K
Mestecky
Jiri
J
Moro
Itaru
I
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D001483:Base Sequence; D002417:Cattle; D002478:Cells, Cultured; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D005091:Exons / Q000235:genetics; D005803:Genes, Immunoglobulin; D017930:Genes, Reporter; D007133:Immunoglobulin Joining Region / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014158:Transcription, Genetic; D014162:Transfection
D007133:Immunoglobulin Joining Region; D011993:Recombinant Fusion Proteins