Table 1.

Ubiquitin conjugation, binding and processing proteins in ERAD

Protein (human)	Other names	Protein (yeast)	Function	Ub-related domains	Other domains	L	M	C	TM
Uba1		Uba1p	Ubiquitin-activating enzyme					X	–
Ube2j1, Ube2j2	Ubc6e	Ubc6p	Ubiquitin-conjugating enzyme	UBCc			X	X	TA
Ube2g2		Ubc7p	Ubiquitin-conjugating enzyme	UBCc				X	–
Hrd1	Synoviolin	Hrd1p	Ubiquitin ligase	RING	VBMa	X	X	X	6
TEB4	March IV	Doa10p	Ubiquitin ligase	RING		X	X	X	12
gp78	AMFR, RNF45		Ubiquitin ligase	RING, CUEb, G2BR	VIMa	X	X	X	6
RNF5	RMA1		Ubiquitin ligase	RING		X	X	X	2
RNF170			Ubiquitin ligase	RING		X	X	X	3
Trc8	RNF138		Ubiquitin ligase	RING		X	X	X	8
RNF103	Kf-1		Ubiquitin ligase	RING		X	X	X	4
RFP2			Ubiquitin ligase	RING	B-box	X	X	X	T1
Fbx2			Ubiquitin ligase	F-Box				X	–
Fbx6			Ubiquitin ligase	F-Box				X	–
Parkin	PARK2		Ubiquitin ligase	RING, UBL	IBR			X	–
CHIP			Ubiquitin ligase	U-Box	TPR			X	–
UBE4a		Ufd2p	Ubiquitin ligase	U-Box				X	–
USP13			Deubiquitinase	UBAb (2)				X	–
USP25			Deubiquitinase	UIMb (2), UBAb	SIM			X	–
YOD1	OTUD2		Deubiquitinase	OTU, UBX				X	–
Ataxin-3			Deubiquitinase	UIMb	Josephin, VBMa			X	–
OTUB1			Deubiquitinase	OTU				X	–
VCIP135	VCPIP		Deubiquitinase	OTU				X	–
HERP		Usa1p	Scaffolding	UBL			X	X	MA
TMUB1			Scaffolding	UBL	NES	X	X	X	2
FAM8A1			Ubiquitin-ligase cofactor			X	X	X	3
AUP1		Cue1p	E2 recruitment, ubiquitin binding	CUEb, G2BR			X	X	MA

Common and alternate mammalian ERAD-component names are given, along with yeast orthologs. Putative function within ERAD is shown, in addition to ubiquitin-related and other domains (numbers of domains are shown in parentheses). Cellular exposure to ER lumen (L), ER membrane (M) or cytoplasm (C) is indicated by ‘X’. Links with the ER membranes are listed under TM: numbers, polytopic TM domains; T1, type I; TA, tail-anchored; MA, membrane associated.

^ap97/VCP-binding domain.

^bUbiquitin-binding domain.