title: Fluorescent Protein-photoprotein Fusions and Their Applications in Calcium Imaging.
abstract: Calcium-activated photoproteins, such as aequorin, have been used as luminescent Ca2+indicators since 1967. After the cloning of aequorin in 1985, microinjection was substituted by its heterologous expression, which opened the way for a widespread use. Molecular fusion of green fluorescent protein (GFP) to aequorin recapitulated the nonradiative energy transfer process that occurs in the jellyfish Aequorea victoria, from which these two proteins were obtained, resulting in an increase of light emission and a shift to longer wavelength. The abundance and location of the chimera are seen by fluorescence, whereas its luminescence reports Ca2+levels. GFP-aequorin is broadly used in an increasing number of studies, from organelles and cells to intact organisms. By fusing other fluorescent proteins to aequorin, the available luminescence color palette has been expanded for multiplexing assays and for in vivo measurements. In this report, we will attempt to review the various photoproteins available, their reported fusions with fluorescent proteins and their biological applications to image Ca2+dynamics in organelles, cells, tissue explants and in live organisms.
authors.affiliation: BioEmergences Unit (CNRS, USR3695), Université Paris-Saclay, Gif-sur-Yvette, France.
authors.forename: Adil
authors.initials: A
authors.lastname: Bakayan
authors.affiliation: Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Domingo
authors.affiliation: Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Cecilia F
authors.initials: CF
authors.lastname: Vaquero
authors.affiliation: BioEmergences Unit (CNRS, USR3695), Université Paris-Saclay, Gif-sur-Yvette, France.
authors.forename: Nadine
authors.initials: N
authors.lastname: Peyriéras
authors.affiliation: Centro Regional de Investigaciones Biomédicas (CRIB) and Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, Albacete, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Llopis
mesh_terms: D000331:Aequorin / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D004735:Energy Transfer; D008164:Luminescent Proteins / Q000737:chemistry / Q000378:metabolism*; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D000331:Aequorin; D002118:Calcium