A synchronized symphony: Intersecting roles of ubiquitin proteasome system and autophagy in cellular degradation.

ABSTRACT

Eukaryotic cells have evolved dynamic quality control pathways and recycling mechanisms for cellular homeostasis. We discuss here, the two major systems for quality control, the ubiquitin-proteasome system (UPS) and autophagy that regulate cellular protein and organelle turnover and ensure efficient nutrient management, cellular integrity and long-term wellbeing of the plant. Both the pathways rely on ubiquitination signal to identify the targets for proteasomal and autophagic degradation, yet they use distinct degradation machinery to process these cargoes. Nonetheless, both UPS and autophagy operate together as an interrelated quality control mechanism where they communicate with each other at multiple nodes to coordinate and/or compensate the recycling mechanism particularly under development and environmental cues. Here, we provide an update on the cellular machinery of autophagy and UPS, unravel the nodes of their crosstalk and particularly highlight the factors responsible for their differential deployment towards protein, macromolecular complexes and organelles.