Cloning, mapping, and characterization of a human homologue of the yeast longevity assurance gene LAG1

We have identified LASS2, a previously unknown human homologue of the yeast longevity assurance gene LAG1. The LASS2 transcript is highly expressed in liver and kidney, which is very different from the expression of the previ ously identified human LAG1 homologue LAG1Hs-1. Radiation hybrid mapping st udies indicated that LASS2 is located on chromosome 1q11. Yeast two-hybrid screening and glutathione S-transferase pull-down assays showed that the LA SS2 protein interacts with several membrane-associated receptors or transpo rters. Furthermore, LASS2 protein was able to inhibit the colony formation of human hepatoma cells in vitro, which suggests that this gene may be invo lved in the regulation of cell growth.