Lpts Lpts And Preparation Of Antibody - Interacting Protein Lbp2 Gene Cloning And Functional Study Of

LPTS , identified previously by allelic-loss mapping and positional candidate cloning,is a human putative tumor suppressor gebe bcated at chromosome 8p23, can suppress the tumor cell growth and inhibit telomerase activity .We used the purified 6His-LPTS fusion protein to immune rabbits to produce polyclonal antibodies against LPTS and purified the polyclonal antibodies by chromatography. The analyse results of western blotting and immuno fluorescene assay indicated that the poly-antibody can associate with LPTS specificity and its activity is well.We used a yeast two-hybrid systerm with LPTS as the bait to identify LPTS associated proteins. After screening the human brain cDNA library, we identified several proteins associated with LPTS, one of which is named LPTS binding-protein 2. For insight into the function of LBP2, we cloned the LBP2 gene and prepared the poly-antibodies against LBP2. The results of CoIP and GST-Pulldown assay indicated that LBP2 interacts with LPTS in both vivo and vitro,which demonstrate the result of yeast two-hybrid assay. The subcellular localization study revealed that LBP2 colocalizate with LPTS protein and distributed in nucleolus and on telomere in cells. LBP2 and its amino terminus inhibit telomerase in vitro,but its C-terminus does,nt do it. LBP2 also interacts with hTERT in vivo.Our results demonstrate that LBP2 is a LPTS-binding protein and involved in the telomerase activity regulation.