[The cloning and expression of a novel mouse gene mLPTS and its subcellular localization]

A novel mouse gene mLPTS was cloned by EST assembling, RT-PCR and DNA sequencing. The gene fragment for mLPTS is 1244 bp in length, encoding a protein of 332 amino acids. The amino acid sequence of mLPTS has 78% homologue with that of LPTS gene, which is a novel liver cancer-related gene identified through positional candidate cloning stratage by our laboratory. The expression of LPTS gene was ubiquitous in normal human tissues, whereas levels appeared to be significantly reduced, or sometime undetectable in HCC cells and neoplastic tissues, and it might be involved in the negative regulation of cell proliferation. The expression of mLPTS gene was found in all mouse tissues analyzed, same with that of LPTS gene in human. There was only one transcript for mLPTS gene in mouse tissues. The phylogenetic tree was constructed through the amino acids sequence analysis and the study of the sequence homologue among different species. Next, mLPTS gene was cloned into green fluorescent protein eukarytic expression vector and then transfected into CHO cell line. The green fluorescent was mostly limited in the nucleolus, showing that the gene products of mLPTS in eukaryocytes were located in the nucleolus.