| dc.creator | Alfonzo R., Marcelo J. | |
| dc.creator | González de Alfonzo, Ramona | |
| dc.creator | Alfonzo-González, Marcelo | |
| dc.creator | Lippo de Becemberg, Itala | |
| dc.date | 2017-01-09T20:56:26Z | |
| dc.date | 2017-01-09T20:56:26Z | |
| dc.date | 2015-11 | |
| dc.date.accessioned | 2022-10-28T01:19:58Z | |
| dc.date.available | 2022-10-28T01:19:58Z | |
| dc.identifier | 1532-4281 | |
| dc.identifier | http://hdl.handle.net/10872/13988 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/4947632 | |
| dc.description | Muscarinic agonists induce the activation of the airway smooth muscle (ASM) leading to
smooth muscle contraction, important in asthma. This activation is mediated through M2/M3
muscarinic acetylcholine receptors (mAChRs). Muscarinic receptor activity, expressed as
[3H]QNB binding at plasma membranes from bovine tracheal smooth muscle (BTSM), increased
with cGMP and was augmented significantly cGMP plus ATP but diminished with the PKG-II
inhibitor, Sp-8-pCPT-cGMPS. The [3H]-QNB binding was accelerated by okadaic acid, (OKA), a
protein phosphatase (PPase) inhibitor. These two results indicated the involvement of a
membrane-bound PPase. Moreover, a cGMP-dependent-[32P]gATP phosphorylation of plasma
membranes from BTSM was stimulated at low concentrations of muscarinic agonist
carbamylcholine (CC). However, higher amounts of CC produced a significant decrement of
[32P]-labeling. A selective M3mAChR antagonist, 4-DAMP produced a dramatic inhibition of the
basal and CC-dependent [32P]-labeling. The [32P] labeled membrane sediments were detergent
solubilized and immunoprecipitated with specific M2/M3mAChR antibodies. The M3mAChR
immuno-precipitates exhibited the highest cGMP-dependent [32P]-labeling, indicating it is a
PKG-II substrate. Experiments using synthetic peptides from the C-terminal of the third
intracellular loop (i3) of both M2mAChR (356–369) and M3mAChR (480–493) as external PKG-II
substrates resulted in the i3M3-peptide being heavily phosphorylated. These results indicated
that PKG-II phosphorylated the M3mAChR at the i3M3 domain (480MSLIKEKK485), suggesting that
Ser481 may be the target. Finally, this phosphorylation site seems to be regulated by a
membrane-bound PPase linked to muscarinic receptor. These findings are important
to understand the role of M3mAChR in the patho-physiology of ASM involved in asthma
and COPD. | |
| dc.language | en | |
| dc.publisher | Journal of Receptors and Signal Transduction | |
| dc.relation | Vol. 35;4 | |
| dc.subject | cGMP | |
| dc.subject | carbamylcholine | |
| dc.subject | muscarinic receptors | |
| dc.subject | tracheal smooth muscle | |
| dc.title | Muscarinic drugs regulate the PKG-II-dependent phosphorylation of M3 muscarinic acetylcholine receptors at plasma membranes from airway smooth muscle | |
| dc.type | Article | |
