Table 1.

Ubiquitin dependent autophagy receptors and their function.

Autophagy Receptor	Substrates	Function and Associated Pathologies	Refs
SQSTM1/p62	General autophagy Protein aggregates Mitochondria Pathogens Lipids Peroxisomes Lysosomes	The most universal autophagy receptor, p62, is involved in cellular stress response and the clearance of protein aggregates, defective organelles as well as invading pathogens. Defects in p62 are associated with Paget disease of bone, amyotrophic lateral sclerosis, and frontotemporal lobar degeneration	[58,59,80,159,174,175]
NBR1	Protein aggregates Mitochondria Peroxisomes	NBR1 is involved in aggrephagy and mitophagy, but is the main receptor for pexophagy	[60,61,62,130,176]
OPTN	General autophagy Protein aggregates Mitochondria Pathogens	OPTN acts as an autophagy receptor for several substrates. Its phosphorylation by TBK1 enhances its function thus facilitating the clearance of Salmonella; it acts as primary mitophagy receptor; mutations in OPTN were found to cause amyotrophic lateral sclerosis, and OPTN in present in protein inclusions found in several neurodegenerative diseases	[53,78,146]
NDP52	Mitochondria Pathogens	NDP52 interacts with LC3-C via noncanonical LIR motif and facilitates autophagosome maturation. It is the primary mitophagy receptor and collaborates with p62 for pathogen clearance	[62,158,177]
TAX1BP1	MitochondriaPathogens Lysosomes	Promotes autophagy flux in activated T cells, and is recruited to damaged lysosomes facilitating their elimination	[143,178]
TOLLIP	Protein aggregates	Facilitates degradation of protein aggregates such as huntingtin-derived polyQ proteins	[95]