Smooth Myocytes - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 393

Tabl e 8. 6. G-protein-coupled receptors and their effects in airway smooth myocytes
(Source: [ 722 ]; A i : adenosine receptor; AR: adrenergic receptor; B i : bradykinin receptor;
CysLT i : cysteinyl leukotriene receptor; EP i : prostanoid receptor; ET x : endothelin receptor; H i :
histamine receptor; IP: prostanoid (prostacyclin) receptor; LPA i : lysophosphatidic acid receptor;
M i : muscarinic acetylcholine receptor; NK i : neurokinin receptor; PAR i : peptidase-activated
receptor; RasGRF: Ras guanosine nucleotide-releasing factor [RasGEF]; RasGRP: Ras guanosine
nucleotide-releasing protein [RasGEF]; S1P i : sphingosine 1-phosphate receptor; TP: prostanoid
(thromboxane A2) receptor; VIPR: vasoactive intestinal peptide receptor; 5HT i : metabotropic
serotonin (or 5-hydroxytryptamine) receptors).

GPCR Main G protein Function

Type partner

5HT 2 C Gq PLC-IP 3 -Ca-RasGRF1-Ras-ERK1/2 axes

Gi Contraction, growth potentiation

α 1AR Gq

β 2AR Gs Relaxation, growth inhibition,

regulation of cytokine synthesis

A 1 Gi Contraction

A 2B Gs Relaxation

A 3 Gq

B 2 Gq Contraction

CysLT 1 Gq Contraction

EP 2 Gs Relaxation, growth inhibition,

regulation of cytokine synthesis

IP Gs Growth inhibition

TP Gq Contraction, growth potentiation

ET A -ET B Gq Contraction, growth potentiation

H 1 Gq Contraction, growth potentiation

LPA 1 -LPA 4 Gq, Gi, G12/13 Growth stimulation,

S1P 1 -S1P 3 Gq, Gi, G12/13 Regulation of cytokine synthesis

M 2 Gi

M 3 Gq Contraction, growth potentiation

NK 1 -NK 2 Gq Contraction, growth potentiation

PA R 1 -PAR 3 Gq, Gi, G12/13 Growth stimulation and potentiation

P2Y Gq

VIPR Gs Relaxation, growth inhibition

Rapid desensitization results from receptor phosphorylation by G-protein-
coupled receptor kinases (GRK). Arrestin binding mediated by GRKs initiates
receptor endocytosis for resensitization after recycling to the plasma membrane.