National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease
HHSN261200800001E
米国
Department of Energy (United States)
DE-AC05-00OR22725
米国
引用
ジャーナル: J Biol Chem / 年: 2020 タイトル: Biochemical and structural analyses reveal that the tumor suppressor neurofibromin (NF1) forms a high-affinity dimer. 著者: Mukul Sherekar / Sae-Won Han / Rodolfo Ghirlando / Simon Messing / Matthew Drew / Dana Rabara / Timothy Waybright / Puneet Juneja / Hugh O'Neill / Christopher B Stanley / Debsindhu Bhowmik / ...著者: Mukul Sherekar / Sae-Won Han / Rodolfo Ghirlando / Simon Messing / Matthew Drew / Dana Rabara / Timothy Waybright / Puneet Juneja / Hugh O'Neill / Christopher B Stanley / Debsindhu Bhowmik / Arvind Ramanathan / Sriram Subramaniam / Dwight V Nissley / William Gillette / Frank McCormick / Dominic Esposito / 要旨: Neurofibromin is a tumor suppressor encoded by the gene, which is mutated in Rasopathy disease neurofibromatosis type I. Defects in lead to aberrant signaling through the RAS-mitogen-activated ...Neurofibromin is a tumor suppressor encoded by the gene, which is mutated in Rasopathy disease neurofibromatosis type I. Defects in lead to aberrant signaling through the RAS-mitogen-activated protein kinase pathway due to disruption of the neurofibromin GTPase-activating function on RAS family small GTPases. Very little is known about the function of most of the neurofibromin protein; to date, biochemical and structural data exist only for its GAP domain and a region containing a Sec-PH motif. To better understand the role of this large protein, here we carried out a series of biochemical and biophysical experiments, including size-exclusion chromatography-multiangle light scattering (SEC-MALS), small-angle X-ray and neutron scattering, and analytical ultracentrifugation, indicating that full-length neurofibromin forms a high-affinity dimer. We observed that neurofibromin dimerization also occurs in human cells and likely has biological and clinical implications. Analysis of purified full-length and truncated neurofibromin variants by negative-stain EM revealed the overall architecture of the dimer and predicted the potential interactions that contribute to the dimer interface. We could reconstitute structures resembling high-affinity full-length dimers by mixing N- and C-terminal protein domains The reconstituted neurofibromin was capable of GTPase activation , and co-expression of the two domains in human cells effectively recapitulated the activity of full-length neurofibromin. Taken together, these results suggest how neurofibromin dimers might form and be stabilized within the cell.