Prokaryotic expression, purification of a novel candidate tumor suppressor gene FUS1 and characterization of its polyclonal antibodies

摘要

FUS1 is a novel candidate tumor suppressor gene identified in human chromosome 3p21.3. Its expression showed significantly reduction or even loss in lung cancer and other types of cancers. In order to further investigate the biological function of FUS1 protein, FUS1 cDNA from MRC-5 cells was amplified by RT-PCR and cloned into prokaryotic expression vector pQE-30. The recombinant expression plasmids were transformed into M15 strain and grown at 20℃ or 37℃. SDS–PAGE analysis revealed that the accumulation of the recombinant protein FUS1 (rFUS1) in inclusion body forms reached maxium amount when induced with 0.5 mM IPTG for 5 h at 37℃. The inclusion bodies were solubilized in 2M urea and purified by a 6 ×His tagged affinity column under denaturing condition. The purified rFUS1 was identified by electrospray ionization-mass spectrometry (ESI-MS) and tested for purity by HPLC chromatography. The purified rFUS1 proteins were then used to immunize rabbits to obtain anti-human FUS1 polyclonal antibodies, which were suitable to detect both the recombinant exogenous FUS1 and the endogenous FUS1 from tissues and cells by western blot and immunohistochemistry, Available purified rFUS1 proteins and self-prepared polyclonal antibodies against FUS1 may provide effective tools for further studies on biological function and application of FUS1.