TY - JOUR
T1 - Rapid constitutive and ligand-activated endocytic trafficking of P2X 3 receptor
AU - Vacca, Fabrizio
AU - Giustizieri, Michela
AU - Ciotti, Maria Teresa
AU - Mercuri, Nicola Biagio
AU - Volonté, Cinzia
PY - 2009/5
Y1 - 2009/5
N2 - P2X receptors mediate a variety of physiological actions, including smooth muscle contraction, neuro-endocrine secretion and synaptic transmission. Among P2X receptors, the P2X3 subtype is expressed in sensory neurons of dorsal root- and trigeminal-ganglia, where it performs a well-recognized role in sensory and pain transmission. Recent evidence indicates that the strength of P2X3-mediated responses is modulated in vivo by altering the number of receptors at the plasma membrane. In the present study, we investigate the trafficking properties of P2X3 receptor in transfected HEK293 cells and in primary cultures of dorsal root ganglion neurons, finding that P2X 3 receptor undergoes rapid constitutive and cholesterol-dependent endocytosis. We also show that endocytosis is accompanied by preferential targeting of the receptor to late endosomes/lysosomes, with subsequent degradation. Furthermore, we observe that at steady state the receptor localizes predominantly in lamp1-positive intracellular structures, with a minor fraction present at the plasma membrane. Finally, the level of functional receptor expressed on the cell surface is rapidly up-regulated in response to agonist stimulation, which also augments receptor endocytosis. The findings presented in this work underscore a very dynamic trafficking behavior of P2X3 receptor and disclose a possible mechanism for the rapid modulation of ATP-mediated responses potentially relevant during physiological and pathological conditions.
AB - P2X receptors mediate a variety of physiological actions, including smooth muscle contraction, neuro-endocrine secretion and synaptic transmission. Among P2X receptors, the P2X3 subtype is expressed in sensory neurons of dorsal root- and trigeminal-ganglia, where it performs a well-recognized role in sensory and pain transmission. Recent evidence indicates that the strength of P2X3-mediated responses is modulated in vivo by altering the number of receptors at the plasma membrane. In the present study, we investigate the trafficking properties of P2X3 receptor in transfected HEK293 cells and in primary cultures of dorsal root ganglion neurons, finding that P2X 3 receptor undergoes rapid constitutive and cholesterol-dependent endocytosis. We also show that endocytosis is accompanied by preferential targeting of the receptor to late endosomes/lysosomes, with subsequent degradation. Furthermore, we observe that at steady state the receptor localizes predominantly in lamp1-positive intracellular structures, with a minor fraction present at the plasma membrane. Finally, the level of functional receptor expressed on the cell surface is rapidly up-regulated in response to agonist stimulation, which also augments receptor endocytosis. The findings presented in this work underscore a very dynamic trafficking behavior of P2X3 receptor and disclose a possible mechanism for the rapid modulation of ATP-mediated responses potentially relevant during physiological and pathological conditions.
KW - α,β-methyleneATP
KW - Biotinylation
KW - Endocytosis
KW - Internalization
KW - Purinergic
KW - Ubiquitin
UR - http://www.scopus.com/inward/record.url?scp=65649096215&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=65649096215&partnerID=8YFLogxK
U2 - 10.1111/j.1471-4159.2009.06029.x
DO - 10.1111/j.1471-4159.2009.06029.x
M3 - Article
C2 - 19519775
AN - SCOPUS:65649096215
VL - 109
SP - 1031
EP - 1041
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
SN - 0022-3042
IS - 4
ER -