TRAF molecules in cell signaling and in human diseases

Table 2 Substrates of the E3 ligase activity of TRAFs

Substrates (Lys residues of ubiquitination)	E3 ligases	Receptor signaling	References
TRAFs
TRAF2	TRAF2	TNF-R1/2	[184]
TRAF3	TRAF3	TLR3, TLR4	[92, 185]
TRAF5	TRAF5	RIG-I	[139]
TRAF6	TRAF6	TLRs, IL-1R	[17, 23, 82, 89, 179, 186]
Receptors
IL-17R	TRAF6	IL-17	[156]
p75 (Lys274, 280 and 283)	TRAF6	NGF	[65]
TβRI	TRAF6	TGFβ	[169]
Kinases
TAK1 (Lys158)	TRAF6, TRAF2	TNF-R1/2 and IL-1R	[187]
RIP1 (Lys377)	TRAF2	TNF-R1 and IL-1R	[179, 180]
TBK1	TRAF3	TLR3, TLR4	[17, 23, 81]
IKKε	TRAF3	TLR3, TLR4	[17, 23, 81]
IRAK1 (Lys134 and 180)	TRAF6	TLR7, TLR9, IL-1R	[179, 188, 189]
Akt (Lys8 and 14)	TRAF6	IL-1R, IGF-1R	[190]
Fyn (K63)	TRAF6	TLR4	[191]
Adaptor proteins
NEMO (Lys285, 321, 325, 326 and 399)	TRAF6	TLRs, IL-1R, NOD2	[17, 23, 82, 111, 192]
TRIF	TRAF2, TRAF6	TLR3, TLR4	[98]
NESCA	TRAF6	TrkA and p75	[193]
LAT (Lys88)	TRAF6	TCR	[176]
Other E3 ligases
cIAP1/2	TRAF2	CD40	[37]
	TRAF6	TLR4-, IL-1R-induced autophagy	[92]
Smurf2	TRAF2	TNF-R2	[194]
Transcription factors
IRF7 (Lys444, 446, and 452)	TRAF6	TLR7, TLR8, TLR9, LMP1, RIG-I	[94, 142, 195]
IRF5 (Lys410 and 411)	TRAF6	NOD2, TLR7, TLR9	[196, 197]
Regulators of mRNA stability
Tristetraprolin	TRAF2	TNF-R1	[198]
Autophagy proteins
Beclin 1 (Lys117)	TRAF6	TLR4-, IL-1R-induced autophagy	[199]
NDP52	TRAF6	TLR3-induced autophagy	[200]
Regulators of ROS production
ECSIT	TRAF6	TLR1, 2, 4-induced ROS production	[93]