Abstract：Natural resistance-associated macrophage protein 1(NRAMP1) can defense the invasion of the intracellular bacteria such as Mycobacterium and Brucella to improve the ability of resisting disease. In this study we cloned a NRAMP1 isoform from the spleen of Qinchuan Bos Taurus. Sequence analysis showed that NRAMP1 isoform had a third intron in comparison with NRAMP1, which resulted in the protein only containing 200 amino acids because the translation stopped in the third intron. In order to get further study on the expression of NRAMP1-ISO, we constructed the prokaryotic expression vector pET-41-NRAMP1-ISO and the eukaryotic expression vector pEGFP-NRAMP1-ISO. The prokaryotic expression vector pET-41-NRAMP1-ISO could efficiently express in the BL21 Escherichia coli under different concentrations of the IPTG. The eukaryotic expression vector pEGFP-NRAMP1-ISO could both express in the nucleus and the cytoplasm of the bovine fibroblast while NRAMP1 was normally expressed around the lysosome membrane in the cytoplasm. Semi-quantitative RT-PCR showed that NRAMP1-ISO gene was highly expressed in the heart, spleen and lung while lowly expressed in the brain, pancreas and the genital ridge. The results provided the useful imformation for further anzlyzing the function of NRAMP1-ISO gene.
