My laboratory uses genetic approaches to study genes that cause nervous system and other tumors. Through family linkage studies and loss of heterozygosity analysis, we localized and cloned the neurofibromatosis 2 tumor suppressor which we named merlin, for its similarity with moesin, ezrin and radixin, membrane-cytoskeleton linker proteins (ERMs). Absence of functional merlin is associated with the initiation of schwannomas and meningiomas in both familial and sporadic cases. Loss of merlin is also a frequent event in malignant mesothelioma and can cause osteosarcomas and other malignant tumors in mice. We are now concentrating on biochemical/cell biological approaches to delineating the normal function of merlin in relation to the ERMs, the proteins with which it interacts, the signaling pathways on which it impinges and the effects of disease producing mutations on these activities. We are also exploring the potential for merlin replacement in deficient tumor cells. The group is also engaged in collaborative studies of the neurofibromatosis 1 protein, neurofibromin, and its relationship to ras and protein kinase A signaling pathways in Drosophila and man and in attempts to identify new tumor suppressor genes (e.g. in meningioma and colon cancer) using rearrangements in primary tumor cells.