Avian interleukin-12beta (p40): cloning and characterization of the cDNA and gene.
We isolated the chicken interleukin-12 (ChIL-12) p40 cDNA from a concanavalin A (ConA)-stimulated spleen cDNA library using the PCR with primers based on a partial 3' EST sequence in a chicken EST library. The cDNA encodes a polypeptide of 315 amino acids (aa), with a predicted mature peptide of 300 aa. ChIL-12 p40 has 46% and 41% amino acid identity with human (HuIL-12) and murine IL-12 (MuIL-12) p40, respectively. We also isolated a partial turkey IL-12 (TuIL-12) p40 cDNA sequence with 95% predicted aa identity with ChIL-12 p40. The structures of the ChIL-12 p40 gene and its promoter were determined by direct sequencing of a chicken BAC identified by hybridization with the cDNA. The gene structures of HuIL-12, MuIL-12, and ChIL-12 p40 all differ. The promoter of the ChIL-12 p40 gene shares some (an ETS consensus sequence, a C/EBP binding site, and a TATA box) but not all (an NF-kappaB binding site and a GA12 site are absent) of the transcription factor binding sites identified in the human and murine promoters. IL-12 p40 mRNA expression was identified in a wide variety of tissues and in B, T, and macrophage cell lines by RT-PCR.
Balu
Sucharitha
S
Institute for Animal Health, Compton, Berkshire RG20 7NN, U.K. sucharitha.balu@bsrc.ac.uk
Kaiser
Pete
P
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D019143:Evolution, Molecular; D007178:Inbreeding; D018664:Interleukin-12 / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D014422:Turkeys / Q000235:genetics*
D018076:DNA, Complementary; D012333:RNA, Messenger; D018664:Interleukin-12