Publication Date:
2019
Description:
〈p〉Mutations in RAS signaling pathway components cause diverse neurodevelopmental disorders, collectively called RASopathies. Previous studies have suggested that dysregulation in RAS–extracellular signal–regulated kinase (ERK) activation is restricted to distinct cell types in different RASopathies. Some cases of Noonan syndrome (NS) are associated with gain-of-function mutations in the phosphatase SHP2 (encoded by 〈i〉PTPN11〈/i〉); however, SHP2 is abundant in multiple cell types, so it is unclear which cell type(s) contribute to NS phenotypes. Here, we found that expressing the NS-associated mutant SHP2〈sup〉D61G〈/sup〉 in excitatory, but not inhibitory, hippocampal neurons increased ERK signaling and impaired both long-term potentiation (LTP) and spatial memory in mice, although endogenous SHP2 was expressed in both neuronal types. Transcriptomic analyses revealed that the genes encoding SHP2-interacting proteins that are critical for ERK activation, such as GAB1 and GRB2, were enriched in excitatory neurons. Accordingly, expressing a dominant-negative mutant of GAB1, which reduced its interaction with SHP2〈sup〉D61G〈/sup〉, selectively in excitatory neurons, reversed SHP2〈sup〉D61G〈/sup〉-mediated deficits. Moreover, ectopic expression of GAB1 and GRB2 together with SHP2〈sup〉D61G〈/sup〉 in inhibitory neurons resulted in ERK activation. These results demonstrate that RAS-ERK signaling networks are notably different between excitatory and inhibitory neurons, accounting for the cell type–specific pathophysiology of NS and perhaps other RASopathies.〈/p〉
Print ISSN:
1945-0877
Electronic ISSN:
1937-9145
Topics:
Biology
,
Medicine
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