Analogues of the nicotinic acid adenine dinucleotide phosphate (NAADP) antagonist Ned-19 indicate two binding sites on the NAADP receptor

Daniel Rosen, Alexander M. Lewis, Akiko Mizote, Justyn M. Thomas, Parvinder K. Aley, Sridhar R. Vasudevan, Raman Parkesh, Antony Galione, Minoru Izumi, A. Ganesan, Grant C. Churchill

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Nicotinic acid adenine dinucleotide phosphate (NAADP) is a Ca2+-releasing messenger. Biological data suggest that its receptor has two binding sites: one high-affinity locking site and one low-affinity opening site. To directly address the presence and function of these putative binding sites, we synthesized and tested analogues of the NAADP antagonist Ned-19. Ned-19 itself inhibits both NAADP-mediated Ca2a release and NAADP binding. A fluorometry bioassay was used to assess NAADP-mediated Ca2+ release, whereas a radioreceptor assay was used to assess binding to theNAADPreceptor (only at the high-affinity site). In Ned-20, the fluorine is para rather than ortho as in Ned-19. Ned-20 does not inhibit NAADP-mediated Ca2+ release but inhibits NAADP binding. Conversely, Ned-19.4 (a methyl ester of Ned-19) inhibits NAADP-mediated Ca2+ release but cannot inhibit NAADP binding. Furthermore, Ned-20 prevents the self-desensitization response characteristic ofNAADP in sea urchin eggs, confirming that this response is mediated by a high-affinity allosteric site to which NAADP binds in the radioreceptor assay. Collectively, these data provide the first direct evidence for two binding sites (one high- and one lowaffinity) on the NAADP receptor.

Original languageEnglish
Pages (from-to)34930-34934
Number of pages5
JournalJournal of Biological Chemistry
Volume284
Issue number50
DOIs
Publication statusPublished - Dec 11 2009

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Analogues of the nicotinic acid adenine dinucleotide phosphate (NAADP) antagonist Ned-19 indicate two binding sites on the NAADP receptor'. Together they form a unique fingerprint.

  • Cite this

    Rosen, D., Lewis, A. M., Mizote, A., Thomas, J. M., Aley, P. K., Vasudevan, S. R., Parkesh, R., Galione, A., Izumi, M., Ganesan, A., & Churchill, G. C. (2009). Analogues of the nicotinic acid adenine dinucleotide phosphate (NAADP) antagonist Ned-19 indicate two binding sites on the NAADP receptor. Journal of Biological Chemistry, 284(50), 34930-34934. https://doi.org/10.1074/jbc.M109.016519