Structure-Function Relationships in Merlin, the Product of the NF2 Causal Gene

Abstract

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the lime for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of Information, Including suggestions for reducing this burden to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302 and to PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)University of Virginia Charlottesville, VA 22904 E-Mail: Zsd4n@virginia. edu SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)U 12b. DISTRIBUTION CODENeurofibromatosis type 2 (NF2) is a debilitating, inherited disorder characterized by tumors of the brain and central nervous system. It is caused by the lack of a functional product of the NF2 gene, known as merlin. Merlin serves as a linker protein between the cell membrane and the cytoskeleton. During the tenure of this grant, we used X-ray crystallography to determine the structure of the N-terminal FERM domain of merlin and we analyzed its functional implications. We also investigated structure-funtion relationships in syntenin, a scaffolding protein that binds to merlin. The structure of the PDZ tandem of syntenin was determined at 1.9 Ä resolution, and we also determined the structure of the 2 nd PDZ domain of syntenin to 0.73 Ä, making it one of the highest resolution protein structures determined thus far. Furthermore, the structures of numerous complexes of syntenin with peptide ligands were determined to gain a better understanding of peptide recognition by PDZ domains. This lead to the formulation of the "combinatorial" model of peptide recognition, which helps explain non-canonical PDZ domain specificities. Biophysical and biochemical techniques were used to characterize the interaction of the PDZ domains with peptides derived from syntenin binding partners including merlin, syndecan, and the interleukin 5 receptor a-subunit. SUBJECT TERMSNF2, merlin, crystallography, syntenin, protein-protein interactions Syndecan, interleukin 5 receptor CC, PDZ domain. Cover. SECURITY CLASSIFICATION OF REPORT UnclassifiedSF 298.Introduction. Body 5 Key Research Accomplishments 20Reportable Outcomes 21 Conclusions 24References 29Appendices 33 IntroductionNeurofibromatosis type 2 (NF2), characterized by tumors of the brain and central nervous system, is a debilitating, inherited disorder affecting 1 in 40,000 people (Evans et al., 2000). Genetic studies revealed that the disorder is caused by mutations in the NF2 gene which codes for a protein known as merlin or schwannomin (Lutchman and Rouleau, 1996). Merlin is a member of the ERM (Ezrin, Radixin, and Moesin) family of proteins, but it is unique in that it acts as a tumor suppressor . Merlin exists in two different splice forms with different C-termini, has no catalytic ac...