Accession Number : AD1047889


Title :   Identifying Neurofibromin Specific Regulatory Nodes for Therapeutic Targeting in NF1


Descriptive Note : Technical Report,30 Sep 2016,29 Sep 2017


Corporate Author : University of California, San Francisco San Francisco United States


Personal Author(s) : McCormick, Frank ; Markegard,Evan ; Tetsu,Osamu ; Mercado,Ellen


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1047889.pdf


Report Date : 01 Oct 2017


Pagination or Media Count : 29


Abstract : The overall goal of the project is to determine how neurofibromin is regulated, and to explore the hypothesis that loss of neurofibromin activity leads to up-regulation of specific receptors. We are building on our earlier discovery, that neurofibromin depends on the adapter protein SPRED1, to function, and we are utilizing the latest technical innovations including CRISPR technology to find genes that regulate neurofibromin SPRED function. To date we have demonstrated that oncogenic EGFR signaling disrupts Spred1-NF1 binding. Mass spectrometry was performed on cells overexpressing EGFRL858R to identify potential phosphorylation sites on Spred1 and NF1 that could disrupt Spred1-NF1 binding by steric hindrance. A serine phosphorylation site on Spred1 was identified in which a phosphomimetic and phosphodeficient mutant decreased or increased Spred1-NF1 binding, respectively. Therefore, phosphorylation of Spred1 at this site by a serine kinase downstream of oncogenic EGFR may disrupt Spred1-NF1 binding. Our findings provide one potential mechanism by which oncogenic EGFR signaling disrupts negative feedback to allow for constitutive Ras signaling. Furthermore, this work may elucidate a novel kinase therapeutic target for restoring NF1 mediated inhibition of Ras.


Descriptors :   mutations , therapy , genes , gene expression , proteins , kinases , nervous system , neoplasms


Subject Categories : Medicine and Medical Research


Distribution Statement : APPROVED FOR PUBLIC RELEASE