The human acetylcholinesterase c-terminal T30 peptide activates neural growth through an alpha 7 nicotinic acetylcholine receptor mTOR pathway
Acetylcholinesterase (AChE) is a highly conserved enzyme responsible for the regulation of acetylcholine signaling within the brain and periphery. AChE has also been shown to participate in non-enzymatic activity and contributing to development and aging. In particular, enzymatic cleavage of the carboxy terminal region of the synaptic AChE isoform, AChE-T, is shown to generate a bioactive T30 peptide that binds to the 7 nicotinic acetylcholine receptor (nAChR) at synapses. Here, we explore intracellular mechanisms of T30 signaling within the human cholinergic neural cell line SH-SY5Y using high performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometry (ESI-MS/MS). Proteomic analysis of cells exposed to (100nM) T30 for 3-days reveals significant changes within proteins important for cell growth. Specifically, bioinformatic analysis identifies proteins that converge onto the mammalian target of rapamycin (mTOR) pathway signaling. Functional experiments confirm that T30 regulates neural cell growth via mTOR signaling and 7 nAChR activation. In addition, T30 was found promote mTORC1 pro-growth signaling through an increase in phosphorylated elF4E, and a decrease in autophagy LC3B-II level. Taken together, our findings define mTOR as a novel pathway activated by the T30 cleavage peptide of AChE and suggest a role for mTOR signaling in cholinergic aspects of brain development, as well as disease.