TABLE 3.

Cellular proteasome substrates

Substrate	Ub/Pathway	Localization	t1/2	Reference
GFPu	Yes/CL1 degron		30 min	Bence et al. (2001)
NLS-GFPu	Yes/CL1 degron	Nuclear	60 min	Bennett et al. (2005)
NES-GFPu	Yes/CL1 degron	Cytosolic	60 min	Bennett et al. (2005)
PSD95-GFPu	Yes/CL1 degron	Postsynaptic	ND	Wang et al. (2008)
SNAP25-GFPu	Yes/CL1 degron	Presynaptic	ND	Wang et al. (2008)
TCR-α–GFP	Yes/ERAD		ND	DeLaBarre et al. (2006)
Ub-M-GFP	Yes/“normal”		“Stable”	Dantuma et al. (2000)
Ub-R-GFP	Yes/N-end rule		“Short”	Dantuma et al. (2000)
UbG76V-GFP	Yes/UFD		“Short”	Dantuma et al. (2000)
UbG76V-dendra2	Yes/UFD		ND	Hamer et al. (2010)
GFP-ODC	No		2 h	Li et al. (1998)

M, methionine; ND, not determined; NES, nuclear export signal; NLS, nuclear localization signal; PSD95, postsynaptic density 95; R, arginine; SNAP25, synaptosomal-associated protein 25; t_1/2, in vivo half-life; TCR-α, T-cell receptor α chain.