title: A cell permeable NPE caged ADP-ribose for studying TRPM2.
abstract: Transient potential receptor melastatin-2 (TRPM2) is a non-selective Ca(2+)-permeable cation channel of the TRPM channel subfamily and is mainly activated by intracellular adenosine diphosphate ribose (ADPR). Here we synthesized a 1-(2-nitrophenyl)ethyl caged ADPR (NPE-ADPR) and found that uncaging of NPE-ADPR efficiently stimulated Ca(2+), Mg(2+), and Zn(2+) influx in a concentration-dependent manner in intact human Jurkat T-lymphocytes. The cation influx was inhibited by inhibitors or knockdown of TRPM2. Likewise, uncaging of NPE-ADPR markedly induced cation entry in HEK 293 cells that overexpress TRPM2. As expected, high temperature increased the ability of the photolyzed NPE-ADPR to induce cation entry, whereas acidic pH inhibited. Moreover, the absence of extracellular Ca(2+) significantly inhibited Mg(2+) and Zn(2+) influx after uncaging NPE-ADPR. On the other hand, the absence of extracellular Na(+) or Mg(2+) had no effect on photolyzed NPE-ADPR induced Ca(2+) entry. Taken together, our results indicated that NPE-ADPR is a cell permeable ADPR analogue that is useful for studying TRPM2-mediated cation entry in intact cells.
authors.affiliation: Department of Physiology, University of Hong Kong, Hong Kong, China.
authors.forename: Peilin
authors.initials: P
authors.lastname: Yu
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Li-He
authors.initials: LH
authors.lastname: Zhang
authors.forename: Hon-Cheung
authors.initials: HC
authors.lastname: Lee
authors.forename: Liangren
authors.initials: L
authors.lastname: Zhang
authors.forename: Jianbo
authors.initials: J
authors.lastname: Yue
mesh_terms: D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology; D036563:Cyclic ADP-Ribose / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D057809:HEK293 Cells; D006801:Humans; D018408:Patch-Clamp Techniques; D050053:TRPM Cation Channels / Q000378:metabolism*
chemical_list: D050053:TRPM Cation Channels; C121934:TRPM2 protein, human; C092958:caged cyclic ADP-ribose; D036563:Cyclic ADP-Ribose; D002118:Calcium