Cloning And Bioinformatics Analysis Of A Full-length CDNA And Partial DNA Of Porcine CR1-like Gene

Objective:In this study, landrace pig was regarded as the research object. For further study of the porcine erythrocyte immune function, we discussed the CRl-like gene in molecular level, and analyzed the characteristics of the gene.Method:The full-length cDNA sequence of the porcine CRl-like gene was acquired from the bone marrow by RT-PCR and RACE and the promoter region of the gene was cloned from the full blood by PCR. Finally, the sequences were analyzed in depth by bioinformatics method.Results:Our results indicated that CRl-like cDNA was 4391bp in length, containing 37bp 5’-untranslated region, an open reading frame of 3996bp by encoding 1331 amino acids and 385bp 3’-untranslated region. The putative amino acid sequence of porcine CRl-like protein consisted of an extracellular portion which had 19 conserved SCR domains, a 23 amino acids transmembrane region and a 44 amino acids cytoplasmic tail. The deduced porcine CR1-like protein was a single polypeptide with the predicted molecular mass of 146.6 kDa and theoretical isoelectric point of 7.95. Porcine CRl-like protein had been predicted to consist of 8 N-glycosylation sites and 76 phosphorylation sites but no O-glycosylation site and signal peptide was found in this protein. The CR1-like protein was rich of alpha helix (1.73%), beta turn (5.26%), beta sheet (18.86%) and radom coil (74.15%) secondary structures. The multiple sequence alignments and phylogenetic analysis indicated that porcine CRl-like shared a low similarity with other mammals. Besides, the researchers also cloned partial genomic sequence of porcine CRl-like gene which located before the first exon. The transcription factor binding site and the CpG island region were analyzed.Conclusion:We cloned porcine CR1-like full length cDNA with the accession number KF286608 in Genebank and its promoter region of CRl-like gene first. The bioinformatics analysis confirmed that the porcine CRl-like was not conserved, and it possessed the basic structure and characteristics of complement receptor.