P2X4 receptors interact with both P2X2 and P2X7 receptors in the form of homotrimers
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
19/10/2012
19/10/2012
2011
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Resumo |
BACKGROUND AND PURPOSE The P2X receptor family consists of seven subunit types - P2X1-P2X7. All but P2X6 are able to assemble as homotrimers. In addition, various subunit permutations have been reported to form heterotrimers. Evidence for heterotrimer formation includes co-localization, co-immunoprecipitation and the generation of receptors with novel functional properties; however, direct structural evidence for heteromer formation, such as chemical cross-linking and single-molecule imaging, is available in only a few cases. Here we examined the nature of the interaction between two pairs of subunits - P2X2 and P2X4, and P2X4 and P2X7. EXPERIMENTAL APPROACH We used several experimental approaches, including in situ proximity ligation, co-immunoprecipitation, co-isolation on affinity beads, chemical cross-linking and atomic force microscopy (AFM) imaging. KEY RESULTS Both pairs of subunits co-localize upon co-transfection, interact intimately within cells, and can be co-immunoprecipitated and co-isolated from cell extracts. Despite this, chemical cross-linking failed to show evidence for heteromer formation. AFM imaging of isolated receptors showed that all three subunits had the propensity to form receptor dimers. This self-association is likely to account for the observed close interaction between the subunit pairs, in the absence of true heteromer formation. CONCLUSIONS AND IMPLICATIONS We conclude that both pairs of receptors interact in the form of distinct homomers. We urge caution in the interpretation of biochemical evidence indicating heteromer formation in other cases. Biotechnology and Biological Sciences Research Council[BB/F001320/1] FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[06/50954-7] CAPES Foundation of the Ministry of Education of Brazil Jean Shanks Foundation James Baird Fund Overseas Research Studentship Cambridge Overseas Trust King`s College Cambridge and the Department of Pharmacology, University of Cambridge |
Identificador |
BRITISH JOURNAL OF PHARMACOLOGY, v.163, n.5, p.1069-1077, 2011 0007-1188 http://producao.usp.br/handle/BDPI/24392 10.1111/j.1476-5381.2011.01303.x |
Idioma(s) |
eng |
Publicador |
WILEY-BLACKWELL |
Relação |
British Journal of Pharmacology |
Direitos |
restrictedAccess Copyright WILEY-BLACKWELL |
Palavras-Chave | #P2X receptors #receptor assembly #subunit interactions #atomic force microscopy #RESONANCE ENERGY-TRANSFER #SODIUM-CHANNEL SUBUNITS #P2X(2) RECEPTOR #DEPENDENT CHANGES #XENOPUS OOCYTES #PORE PROPERTIES #ION CHANNELS #MICROSCOPY #ARCHITECTURE #COMPLEXES #Pharmacology & Pharmacy |
Tipo |
article original article publishedVersion |