. Author manuscript; available in PMC: 2012 Aug 1.

Published in final edited form as: Curr Opin Cell Biol. 2011 May 14;23(4):483–491. doi: 10.1016/j.ceb.2011.04.012

Table 1.

Peripheral protein QC substrates

membrane protein	mutation/condition	degron	PM stability related disease		reference

Mammalian

bile salt export pump (BSEP)	E297G (Cy)	2–3 Ub	↓	progressive familial	[36]
	D482G (Cy)			intrahepatic cholestasis type 2 (PFIC2)
CFTR	rΔF508 (Cy)	poly/multimono Ub	↓	cystic fibrosis (CF)	[*44], [27]
	Δ70 (Cy truncation)	poly/multimono Ub	↓		[*27]
	N894D, N900D (Ex)	poly/multimono Ub	↓		[22]
Na/H exchanger (NHE6)	Δ255–256 (TM)	poly/multimono Ub	↓	Angelman syndrome	[35]
MLC1	multiple (TM or Cy)	ND	↓	megalencephalic leukoencephalopathy with subcortical cysts (MLC)	[66]
HERG	low K+	Ub	↓	type 2 long QT syndrome	[37]
LDL receptor	high salt or low pH (Ex)	ND	↓	hypercholesterolemia	[16]
Dopamine D4.4 receptor	M345T (TM)	poly/multimono Ub	↓	attention deficit hyperactivity disorder	[**28]
Vasopressin V2 receptor	W164S (TM)	poly/multimono Ub	↓	nephrogenic diabetes insipidus	[**28]
alpha-2A adrenergic receptor	D79N (TM)	ND	↓	cardiovascular diseases	[14]
	N422D (TM)	ND	↓		[14]
	Δi3loop (Cy)	ND	↓		[69]
CD4tl-lambda_C	L57C (Cy)	poly/multimono Ub	↓	model protein	[**28]
H⁺/K⁺-ATPase β subunit	N99Q, N130Q, N161Q, N222Q (Ex)	ND	↓	gastric, autoimmune diseases	[18]
κ opioid receptor	N25/39Q (Ex)	ND	↓	pain control, neuronal phenotypes	[19]
δ opioid receptor	N18Q/N33Q (Ex)	ND	↓	pain control, neuronal phenotypes	[20]
GLUT1	N45Y, Q or D (ex)	ND	↓	GLUT1 deficiency syndrome	[70]
EGFR	L858R (Cy), exon 19 deletion (Cy)	poly/multimono Ub	↓	cancer suspectibility	[71]
ErbB2	Hsp90 inhibition	poly/multimono Ub	↓	breast cancer	[72]
TGFBR2	Hsp90 inhibition	poly/multimono Ub	↓	tumor suspectibility	[73]

Yeast

Pma1	Icb1-100	poly/multimono Ub	↓	NA	[29]
	Pma1-7	poly/multimono Ub	↓	NA	[7]
	Pma1-10	poly/multimono Ub	↓	NA	[52]
Gap1	absence of sphingolipids	poly/multimono Ub	↓	NA	[9]

Abbreviations: Cy, cytosolic; Ex, extracellular; TM, transmembrane; Ub, ubiquitin; ND, not determined; ↓, decreasing stability; CFTR, cystic fibrosis transmembrane conductance regulator; HERG, human ether-à-go-go related gene; LDL, low-density lipoprotein; GLUT, glucose transporter; EGFR, epidermal growth factor receptor; ErbbB2, v-erb-b2 erythroblastic leukemia viral oncogene homolog 2; TGFBR2, transforming growth factor (TGF)-beta type II Pma1, H(+)-ATPase; Gap1, general amino acid permease