Proteostatic Signaling & Control of Protein Synthesis

The tremendous diversity and complexity of proteins invariably results in protein misfolding, to which cells have evolved numerous mechanisms of mitigating. Degrading misfolded proteins is perhaps the most intuitive strategy, but also critical to managing proteostasis are the elaborate mechanisms of translational control. Attenuated rates of translation ameliorate protein misfolding by downregulating the flux of new protein and conserving ATP. Loss of translational control, particularly in neurons, constitutes a major proteostatic dysfunction capable of causing or exacerbating neurodegeneration, while interventions aimed at downregulating protein synthesis are generally neuroprotective. In this review, I examine the critical neuronal signaling networks employed to control translation with an emphasis on current research. This includes the Unfolded Protein Response (UPR), the mitochondrial UPR (mtUPR), mTORC1 signaling, and stress granule formation.