title: Direct comparison of a genetically encoded sensor and small molecule indicator: implications for quantification of cytosolic Zn(2+).
abstract: Fluorescent sensors are powerful tools for visualizing and quantifying molecules and ions in living cells. A variety of small molecule and genetically encoded sensors have been developed for studying intracellular Zn(2+) homeostasis and signaling, but no direct comparisons exist, making it challenging for researchers to identify the appropriate sensor for a given application. Here we directly compare the widely used small molecule probe FluoZin-3 and a genetically encoded sensor, ZapCY2. We demonstrate that, in contrast to FluoZin-3, ZapCY2 exhibits a well-defined cytosolic localization, provides estimates of Zn(2+) concentration with little variability, does not perturb cytosolic Zn(2+) levels, and exhibits rapid Zn(2+) response dynamics. ZapCY2 was used to measure Zn(2+) concentrations in 5 different cell types, revealing higher cytosolic Zn(2+) levels in prostate cancer cells compared to normal prostate cells (although the total zinc is reduced in prostate cancer cells), suggesting distinct regulatory mechanisms.
authors.affiliation: Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado-Boulder , UCB 596, Boulder, Colorado 80309, United States.
authors.forename: Yan
authors.initials: Y
authors.lastname: Qin
authors.forename: Jose G
authors.initials: JG
authors.lastname: Miranda
authors.forename: Caitlin I
authors.initials: CI
authors.lastname: Stoddard
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Dean
authors.forename: Domenico F
authors.initials: DF
authors.lastname: Galati
authors.forename: Amy E
authors.initials: AE
authors.lastname: Palmer
mesh_terms: D002478:Cells, Cultured; D003600:Cytosol / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics; D011083:Polycyclic Compounds / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics; D015032:Zinc / Q000032:analysis / Q000737:chemistry*
chemical_list: C451182:FluoZin-3; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D011083:Polycyclic Compounds; D011993:Recombinant Fusion Proteins; C000595253:ZapCY2 protein; D015032:Zinc