Table 1.

The conventional pathway for protein secretion and its energy requirements.

Process	Associated proteins	References
Protein synthesis	Aminoacyl-tRNA synthetases, initiation factors, elongation factors, termination factors, ribosomes	(43)
Protein translocation	SRP, SRP receptor, SEC61, SEC62, SEC63, BiP, GRP170, SIL1, TRAM, TRAP	(4, 40)
Protein folding	OGT, exoglucosidases I and II, calnexin, calreticulin, GT, PDIA3, BiP, GRP-94	(41, 44)
Protein quality control	ER α1,2-mannosidase, EDEMs 1/2/3, BiP, PDIs, OS-9, XTP-3B, SEL1L, ubiquitin activating enzyme (E1), ubiquitin conjugating enzyme (E2), ubiquitin ligase (E3, HRD1), SEC61, derlins, ATPase VCP/p97, 26S proteasome	(41, 45, 46)
COPII and COPIvesicle assembly	SAR1, ARF, SEC12, SEC16, SEC23, SEC24, SEC13, SEC31, COPI subunits, GEFs, GAPs	(47, 48)
Vesicle fusion	Receptors, Rab GTPases, Rab effectors SNARE proteins, SM proteins, SNAP, NSF	(2)
Vesicle transport	Kinesin, dynein, myosins	(9, 49)
Exocytosis	Rab GTPases, Rab effectors SNARE proteins, SM proteins, SNAP, NSF, actin, myosins	(50, 51)

Relevant molecules involved in the different steps of the conventional secretion pathway are listed. Proteins that catalyze ATP hydrolysis are highlighted in bold letters.