title: Optical control of the Ca2+ concentration in a live specimen with a genetically encoded Ca2+-releasing molecular tool.
abstract: Calcium ion (Ca2+) is an important second messenger implicated in the control of many different cellular processes in living organisms. Ca2+ is typically studied by direct visualization using chemically or genetically encoded indicators. A complementary, and perhaps more useful, approach involves direct manipulation of Ca2+ concentration; tools for this exist but are rather poorly developed compared to the indicators at least. Here, we report a photoactivatable Ca2+-releasing protein, photoactivatable Ca2+ releaser (PACR), made by the insertion of a photosensitive protein domain (LOV2) into a Ca2+ binding protein (calmodulin fused with the M13 peptide). As the PACR is genetically encoded, and unlike conventional optical control tools (e.g., channel rhodopsin) not membrane bound, we are able to restrict expression within the cell, to allow subcellular perturbation of Ca2+ levels. In whole animals, we are able to control the behavior of Caenorhabditis elegans with light by expressing the PACR only in the touch neuron.
authors.affiliation: Graduate School of Frontier Biosciences, Osaka University , 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Noritaka
authors.initials: N
authors.lastname: Fukuda
authors.forename: Tomoki
authors.initials: T
authors.lastname: Matsuda
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002147:Calmodulin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002413:Cations, Divalent / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008027:Light; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D015202:Protein Engineering; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D002147:Calmodulin; D002413:Cations, Divalent; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D002118:Calcium