Regulated GPCR Trafficking to the Plasma Membrane: General Issues and the CCR5 Chemokine Receptor Example - GPCR Signalling Complexes: Synthesis, Assembly, Trafficking and Specificity - page 98

Table 6.1 GPCR escort proteins
Escort name GPCRs/ligands Additional functions Associated disease References

RAMP family
RAMP-1

CLR/CGRP binds to VPAC1R 1-4

CaSR/Ca ++
CTR/amylin

RAMP-2 CLR/adreno

medullin

VPAC1R enhanced
signaling binds
to GR and
PTH1R

1, 4

RAMP-3 CLR/CGRP Binds to PTH2R and

VPAC1R

1-4

CaSR/Ca ++
CTR/amylin

REEP family
REEP-1 OR/odorant Hereditary spastic

paraplegia

5, 6
7

TAS2

REEP-2 OR/odorant 5

REEP-3 OR/odorant 5

RTP family
RTP-1 OR/odorant 5

RTP-2 OR/odorant 5

RTP-3 TAS2/bitter

molecules

7

RTP-4 TAS2/bitter

molecules

Targets MOR-DOR
hetero-dimer to the
plasma membrane

7, 8

Other
M10 - M1 V2R MHC class Ib

molecules

9, 10

Neuronal plasticity

MRAP MC2R Familial

glucocorticoid
de fi ciency

11, 12
12

MC5R
(inhibitor)

P11 5-HT 1B R Member of S100

EF-hand calcium-
dependent signaling
modulators

Depression 13-15

CD4 CCR5 Interaction with class II

major histocompat-
ibility complex

16

1: McLatchie et al. ( 1998 ), 2: Muff et al. ( 1999 ), 3: Bouschet et al. ( 2005 ), 4: Christopoulos et al.
( 2003 ), 5: Saito et al. ( 2004 ), 6: Zuchner et al. ( 2006 ), 7: Behrens et al. ( 2006 ), 8: Decaillot et al.
( 2008 ), 9: Loconto et al. ( 2003 ), 10: Olson et al. ( 2006 ), 11: Sebag and Hinkle ( 2007 ) , 12: Sebag
and Hinkle ( 2009 ), 13: Svenningsson et al. ( 2006 ), 14: Doyle and Strominger ( 1987 ) , 15: Alexander
et al. ( 2010 ) , 16: Achour et al. ( 2009 )

(see below). There is also an example where the escort protein for a receptor dis-
plays inhibitory effects on the surface expression of another receptor. Indeed,
while helping the MC2R (the melanocortin 2, ACTH receptor) to reach the cell