Table 1 Proteins required for the autophagy and Cvt pathways

Cargo selection and tethering

Cvt9

Cvt pathway-specific; coiled-coil protein, required to bring prApe1-Cvt19 to the preautophagosomal structure, interacts with Apg1

Cvt19

Cvt pathway-specific; receptor for prApe1

VFT

Cvt pathway-specific; composed of Vps51, Vps52, Vps53 and Vps54. Tethering complex for endosome to late Golgi trafficking; required for localizing prApe1-Cvt19-Cvt9 to the PAS

Tlg2

Cvt pathway-specific; syntaxin homologue

Vps45

Cvt pathway-specific; Sec1 homologue

Vesicle formation/completion

PtdIns 3-kinase complex

Apg6/Vps30

Required for both PtdIns 3-kinase complexes; forms a complex with Vps34 and Vps15 and either Apg14 or Vps38

Apg14/Cvt12

Forms complex with Apg6, Vps34 and Vps15

Vps34

PtdIns 3-kinase

Vps15

Protein kinase required for Vps34 function

Conjugation systems

Apg5

Conjugated with Apg12

Apg7/Cvt2

E1-like activation enzyme for both Apg12 and Aut7

Aut7/Apg8/Cvt5

Ubiquitin-like modifier, conjugated to phosphatidylethanolamine (PE), regulates autophagosome size, needed for Cvt vesicle formation

Apg10

E2 protein conjugating enzyme for Apg12-Apg5

Apg12

Ubiquitin-like modifier, forms Apg12-Apg5 conjugate

Apg16

Coiled-coil protein that binds Apg12-Apg5 conjugate

Aut1/Apg3

E2 protein conjugating enzyme for Aut7-PE

Aut2/Apg4

Cysteine protease processes Aut7 and Aut7-PE

Regulatory machinery

Apg1/Aut3/Cvt10

Serine/threonine kinase; interacts with Apg13

Apg13

Autophagy-specific; phosphoprotein that is dephosphorylated under starvation conditions and interacts with Apg1

Apg17

Autophagy-specific; interacts with Apg1, Cvt13 and Cvt20

Cvt13

Cvt pathway-specific; forms a complex with Cvt20 and Apg1

Cvt18

Localized to the vacuole and perivacuolar compartment

Cvt20

Cvt pathway-specific; forms a complex with Cvt13 and Apg17

Vac8

Cvt pathway-specific; armadillo repeat protein, involved in vacuole inheritance, and nucleus-vacuole

junctions, interacts with Apg13

Apg9 complex

Apg2

Interacts with Apg9

Apg9/Aut9/Cvt7

Integral membrane protein, interacts with Apg2

Early Sec pathway

Sec12

Autophagy-specific; required for recruitment of Sar1 and vesicle formation at the endoplasmic reticulum

Sec16

Autophagy-specific; vesicle coat protein that interacts with Sec23

Sec23

Autophagy-specific; GTPase-activating protein

Sec24

Autophagy specific; vesicle coat component that interacts with Sec23

Docking and fusion

Vam3

Syntaxin homologue, vacuolar t-SNARE

Vti1

cis-Golgi v-SNARE, also found on vacuole

Vam7

SNAP-25 homologue, vacuolar t-SNARE

HOPS

Class C Vps complex composed of Vps11, 16, 18, 33, 39, and 41

Ccz1

Forms a complex with Mon1, interacts with Ypt7

Mon1

Forms a complex with Ccz1

Ypt7

Rab GTPase

Sec18

ATPase, yeast NSF

Sec17

α-SNAP

Vesicle breakdown

Cvt17/Aut5

Integral membrane protein, a putative lipase

Aut4

Integral membrane protein, a permease homologue

Pep4

Vacuolar proteinase A

Prb1/Cvt1

Vacuolar proteinase B