Quantitative proteomic analysis reveals apoE4-dependent phosphorylation of the actin regulating protein VASP

ABSTRACT: Apolipoprotein (apo) E4 is the major genetic risk factor for Alzheimer’s Disease (AD). While neurons generally produce a minority of the apoE in the central nervous system, neuronal expression of apoE increases dramatically in response to stress and is sufficient to drive pathology. Currently, the molecular mechanisms of how apoE4 expression may regulate pathology are not fully understood. Here we expand upon our previous studies measuring the impact of apoE4 on protein abundance to include the analysis of protein phosphorylation and ubiquitylation signaling in isogenic Neuro-2a cells expressing apoE3 or apoE4. We find that apoE4 expression results in the dramatic increase in VASP S235 phosphorylation in a PKA-dependent manner. This phosphorylation results in the loss of VASP interactions with numerous actin cytoskeletal and microtubular proteins. Reduction of VASP S235 phosphorylation via PKA inhibition results in a significant increase in filopodia formation and neurite outgrowth in apoE4-expressing cells to levels beyond that of apoE3. Our results highlight the pronounced and diverse impact of apoE4 on multiple modes of protein regulation and identify potential therapeutic targets to restore apoE4-related cytoskeletal defects.

INSTRUMENT(S): Orbitrap Fusion Lumos, Orbitrap Fusion

ORGANISM(S): Mus Musculus (mouse)

SUBMITTER: Danielle Swaney  

LAB HEAD: Danielle Swaney

PROVIDER: PXD041205 | Pride | 2023-04-08

REPOSITORIES: Pride