Table 1.

Yeast Cvt pathway proteins and their hypothetical human functional homologs

Yeast protein	Function	Interactors	Human protein	Function	Interactors
Atg1	Kinase required for vesicle and PAS formation	Atg1, Atg8, Atg11, Atg13, Atg14, Atg17, Atg18, Atg21, Atg29, Slx5	ULK1/2	Kinase that regulates autophagy156	mAtg13
Atg8	Vesicle component, phagophore expansion, vesicle fusion	Atg1, Atg3, Atg4, Atg7, Atg19, Atg32, Vam3	LC3	Recruited to the phagophore membrane and remains associated with completed vesicle102	p62/SQSTM1
Atg11	Directs receptor-bound cargo to the PAS for packaging into vesicles; required for recruiting other proteins to the PAS	Atg1, Atg9, Atg11, Atg12, Atg17, Atg19, Atg20, Atg29, Atg32	Huntingtin aa 1743–3144	Regulation of early endosome motility89	HAP40/Rab5 complex
			FIP200	Regulation of cell growth, proliferation, cell migration, apoptosis, microtubule dynamics, stress response156,157	mAtg13, ULK1/2, PIASy, p53, FAK, TSC1, Pyk2, ASK1 stathmin, TRAF2
Atg13	Regulatory subunit of Atg1 complex, required for vesicle formation, involved in Atg9/23/27 cycling	Vac8, Atg1, Atg17	mAtg13	Plays an essential role in autophagosome formation, phosphorylated by ULK and mTOR156,158	ULK1/2, FIP200, Atg101
Atg17	Scaffold protein responsible for PAS site organization, stimulates Atg1 kinase activity	Atg1, Atg9, Atg11, Atg12, Atg13, Atg17, Atg24, Atg29, NIP100	Atg101	Important for stability and phosphorylation of ULK and mAtg13158	mAtg13
Atg19	Cvt pathway receptor protein delivers cargo to PAS	Atg8, Atg11, Ubi4	p62/SQSTM1 NBR1	Shuttle proteins transport ubiquitinated proteins to lysosome54,55,93,102,159	LC3, Huntingtin, ubiquitin
Atg20	Sorting nexin for Cvt pathway and endosomal sorting	Atg11, Atg24	Optineurin	Membrane trafficking, cellular morphogenesis59	Huntingtin, Rab8
Atg23	Peripheral membrane protein required for Atg9/Atg27 shuttling/membrane trafficking	Atg9, Atg27	Huntingtin aa 1–586	Contains polyQ repeat, vesicle/membrane trafficking, localizes to microtubules59,77,85,160	HAP-1, Optineurin, p53, Sp1, Akt, CBP, SH3GL3, RasGaP, PSD-95, HIP-1, HYP-J, PACSIN, actin
Atg24	Sorting nexin involved in Cvt pathway and in retrieval of late-Golgi SNAREs from post-Golgi endosomes to the trans-Golgi network	Atg17, Atg20, Cog6, NIP100	HAP-1	Adaptor protein, mediates vesicle trafficking62,161	Huntingtin (171–230) PCM-1, kinesin-like protein, neurofilament M, p150glued
Vac8	Vacuole inheritance, the Cvt pathway, mitophagy, PMN, vacuole/vacuole fusion	Atg13, Vam3, Act1	Huntingtin aa 807–1653	DNA-damage response signal protein45	Cdk5
Vam3	Integral vacuolar membrane protein required for vacuolar assembly and protein trafficking, Golgi to vacuole transport, vesicular fusion, PMN	Atg8, Vac8, Vam3, Vam7	LAMP-2A	Integral lysosomal membrane protein involved in vesicular trafficking and lysosome biogenesis70,150,162	UCH-L1/Hsc70/Hsp90 complex
NIP100	Large subunit of dynactin complex	Atg24	p150glued	Large subunit of dynactin complex62	HAP-1

Select direct interactions listed. Yeast protein data obtained from the Saccharomyces Genome Database: www.yeastgenome.org.