title: Design and Synthesis of a Calcium-Sensitive Photocage.
abstract: Photolabile protecting groups (or "photocages") enable precise spatiotemporal control of chemical functionality and facilitate advanced biological experiments. Extant photocages exhibit a simple input-output relationship, however, where application of light elicits a photochemical reaction irrespective of the environment. Herein, we refine and extend the concept of photolabile groups, synthesizing the first Ca(2+) -sensitive photocage. This system functions as a chemical coincidence detector, releasing small molecules only in the presence of both light and elevated [Ca(2+) ]. Caging a fluorophore with this ion-sensitive moiety yields an "ion integrator" that permanently marks cells undergoing high Ca(2+) flux during an illumination-defined time period. Our general design concept demonstrates a new class of light-sensitive material for cellular imaging, sensing, and targeted molecular delivery.
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, USA.
authors.forename: Laurel M
authors.initials: LM
authors.lastname: Heckman
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, USA.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Grimm
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, USA.
authors.forename: Eric R
authors.initials: ER
authors.lastname: Schreiter
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Kim
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Verdecia
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, USA.
authors.forename: Brenda C
authors.initials: BC
authors.lastname: Shields
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, USA. lavisl@janelia.hmi.org.
authors.forename: Luke D
authors.identifier: 0000-0002-0789-6343
authors.initials: LD
authors.lastname: Lavis
keywords: bioimaging; calcium; fluorescence; ion sensing; photocaging