Journal article icon

Journal article

TPC2 proteins mediate nicotinic acid adenine dinucleotide phosphate (NAADP)- and agonist-evoked contractions of smooth muscle.

Abstract:
Agonists such as those acting at muscarinic receptors are thought to induce contraction of smooth muscle primarily through inositol 1,4,5-trisphosphate production and release of Ca(2+) from sarcoplasmic reticulum. However, the additional Ca(2+)-mobilizing messengers cyclic adenosine diphosphate ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP) may also be involved in this process, the former acting on the sarcoplasmic reticulum, the latter acting on lysosome-related organelles. In this study, we provide the first systematic analysis of the capacity of inositol 1,4,5-trisphosphate, cADPR, and NAADP to cause contraction in smooth muscle. Using permeabilized guinea pig detrusor and taenia caecum, we show that all three Ca(2+)-mobilizing messengers cause contractions in both types of smooth muscle. We demonstrate that cADPR and NAADP play differential roles in mediating contraction in response to muscarinic receptor activation, with a sizeable role for NAADP and acidic calcium stores in detrusor muscle but not in taenia caecum, underscoring the heterogeneity of smooth muscle signal transduction systems. Two-pore channel proteins (TPCs) have recently been shown to be key components of the NAADP receptor. We show that contractile responses to NAADP were completely abolished, and agonist-evoked contractions were reduced and now became independent of acidic calcium stores in Tpcn2(-/-) mouse detrusor smooth muscle. Our findings provide the first evidence that TPC proteins mediate a key NAADP-regulated tissue response brought about by agonist activation of a cell surface receptor.
Publication status:
Published

Actions


Access Document


Publisher copy:
10.1074/jbc.m110.129833

Authors


More by this author
Institution:
University of Oxford
Division:
MSD
Department:
Pharmacology
Role:
Author


Journal:
Journal of biological chemistry More from this journal
Volume:
285
Issue:
32
Pages:
24925-24932
Publication date:
2010-08-01
DOI:
EISSN:
1083-351X
ISSN:
0021-9258


Language:
English
Keywords:
Pubs id:
pubs:106350
UUID:
uuid:29f094d7-528e-4ef9-a3cc-8e2da72493dc
Local pid:
pubs:106350
Source identifiers:
106350
Deposit date:
2012-12-19

Terms of use



Views and Downloads






If you are the owner of this record, you can report an update to it here: Report update to this record

TO TOP