Acetyl-CoA flux maintains intracellular crosstalk and modulats engagement of the secretory pathway

ABSTRACT: Nε-lysine acetylation has emerged as a central mechanism to maintain quality control and protein homeostasis within the Endoplasmic Reticulum (ER) and secretory pathway. The ER acetylation machinery includes AT-1/SLC33A1, a membrane transporter that translocates acetyl-CoA from the cytosol to the ER lumen, and ATase1 and ATase2, two ER membrane-bound acetyltransferases that acetylate ER cargo proteins. Dysfunctional AT-1, as caused by loss-of-function mutations or gene duplication events, results in neurodevelopmental or neurodegenerative disorders. Experiments in our lab have demonstrated that these human diseases can be effectively recapitulated in mouse models. In this thesis, we used two models of dysregulated acetyl-CoA flux: AT-1S113R/+, a model of AT-1 haploinsufficiency, and AT-1 sTg, a model of systemic overexpression of AT-1. First, we examined upstream processes of cytosol-to-ER acetyl-CoA flux by evaluating the cytosolic pool of acetyl-CoA. The aberrant AT-1 models demonstrated distinct metabolic reprogramming of lipid metabolism and mitochondria bioenergetics. Dysregulated acetyl-CoA flux resulted in global changes at the level of the proteome and the acetyl-proteome. Second, we examined the downstream consequences of cytosol-to-ER acetyl-CoA flux. Specifically, we investigated the engagement and functional organization of the secretory pathway and used N-glycoproteomics to determine the quality of secreted proteins. Aberrant AT-1 models demonstrated reorganization of the ER, Golgi, and ERGIC, as well as a delay in glycoproteins clearing the Golgi apparatus. Additionally, AT-1 sTg mice showed a marked delay in protein trafficking to the cell surface. The N-glycoproteome revealed significant alterations, highlighting changes in the quality of the secretome.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Brain

SUBMITTER: Yusi Cui  

LAB HEAD: Lingjun Li

PROVIDER: PXD019770 | Pride | 2021-09-09

REPOSITORIES: Pride