Brown HLD, Kaun KR, Edgar BA. The small GTPase Rheb affects central brain neuronal morphology and memory formation in Drosophila.
PLoS One 2012;
7:e44888. [PMID:
23028662 PMCID:
PMC3446999 DOI:
10.1371/journal.pone.0044888]
[Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 08/14/2012] [Indexed: 01/26/2023] Open
Abstract
Mutations in either of two tumor suppressor genes, TSC1 or TSC2, cause tuberous sclerosis complex (TSC), a syndrome resulting in benign hamartomatous tumors and neurological disorders. Cellular growth defects and neuronal disorganization associated with TSC are believed to be due to upregulated TOR signaling. We overexpressed Rheb, an upstream regulator of TOR, in two different subsets of D. melanogaster central brain neurons in order to upregulate the Tsc-Rheb-TOR pathway. Overexpression of Rheb in either the mushroom bodies or the insulin producing cells resulted in enlarged axon projections and cell bodies, which continued to increase in size with prolonged Rheb expression as the animals aged. Additionally, Rheb overexpression in the mushroom bodies resulted in deficiencies in 3 hr but not immediate appetitive memory. Thus, Rheb overexpression in the central brain neurons of flies causes not only morphological phenotypes, but behavioral and aging phenotypes that may mirror symptoms of TSC.
Collapse