Protein quality control by the proteasome and autophagy: A regulatory role of ubiquitin and liquid-liquid phase separation

•The ubiquitin-proteasome system (UPS) and autophagy are part of the cellular quality control network to maintain the integrity of the cellular proteome.•Ubiquitin and ubiquitin-binding proteins play a crucial role in proteasomal and autophagosomal degradation, in determining the pathway choice and in the crosstalk between the UPS and autophagy.•Liquid-liquid phase separation has emerged as an additional player in the spatiotemporal regulation of protein quality control in a ubiquitin-dependent manner.