title: Structural and biochemical consequences of NF1 associated nontruncating mutations in the Sec14-PH module of neurofibromin.
abstract: Neurofibromatosis type 1 (NF1) is a common genetic disorder caused by alterations in the tumor suppressor gene NF1. Clinical manifestations include various neural crest derived tumors, pigmentation anomalies, bone deformations, and learning disabilities. NF1 encodes the Ras specific GTPase activating protein (RasGAP) neurofibromin, of which the central RasGAP related domain as well as a Sec14-like (residues 1560-1699) and a tightly interacting pleckstrin homology (PH)-like (1713-1818) domain are currently well defined. However, patient-derived nontruncating mutations have been reported along the whole NF1 gene, suggesting further essential protein functions. Focusing on the Sec14-PH module, we have engineered such nontruncating mutations and analyzed their implications on protein function and structure using lipid binding assays, CD spectroscopy and X-ray crystallography. Although lipid binding appears to be preserved among most nontruncating mutants, we see major structural changes for two of the alterations. Judging from these changes and our biochemical data, we suggest the presence of an intermolecular contact surface in the lid-lock region of the protein.
authors.affiliation: European Molecular Biology Laboratory (EMBL), Structural and Computational Biology Unit, Heidelberg, Germany. welti@embl.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Welti
authors.forename: Sonja
authors.initials: S
authors.lastname: Kühn
authors.forename: Igor
authors.initials: I
authors.lastname: D'Angelo
authors.forename: Britta
authors.initials: B
authors.lastname: Brügger
authors.forename: Dieter
authors.initials: D
authors.lastname: Kaufmann
authors.forename: Klaus
authors.initials: K
authors.lastname: Scheffzek
mesh_terms: D002478:Cells, Cultured; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D017353:Gene Deletion; D020404:Glycerophospholipids / Q000378:metabolism; D006801:Humans; D009154:Mutation; D009456:Neurofibromatosis 1 / Q000235:genetics*; D025542:Neurofibromin 1 / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D017510:Protein Folding
chemical_list: D020404:Glycerophospholipids; D025542:Neurofibromin 1