Novel subcellular regulatory mechanisms of protein homeostasis and its implications in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron degenerative disorder. Protein aggregates induce various forms of neuronal dysfunction and represent pathological hallmarks in ALS patients. Reducing protein aggregates could be a promising therapeutic strategy for ALS. While most studies have focused on cytoplasmic protein homeostasis, neurons adaptively reduce aggregates across subcellular compartments during stress through previously uncharacterized mechanisms. Here, we summarize novel compartment-specific proteostatic mechanisms: (1) the ERAD/RESET pathways, (2) HSPs-mediated nuclear sequestration, (3) mitochondrial aggregate import (MAGIC), (4) neurite-localized UPS/autophagosome and NMP, and (5) exopher-mediated extracellular disposal. These mechanisms collectively ensure cellular stress adaptation and provide novel therapeutic targets for ALS treatment.