title: Far-red fluorescent tags for protein imaging in living tissues.
abstract: A vast colour palette of monomeric fluorescent proteins has been developed to investigate protein localization, motility and interactions. However, low brightness has remained a problem in far-red variants, which hampers multicolour labelling and whole-body imaging techniques. In the present paper, we report mKate2, a monomeric far-red fluorescent protein that is almost 3-fold brighter than the previously reported mKate and is 10-fold brighter than mPlum. The high-brightness, far-red emission spectrum, excellent pH resistance and photostability, coupled with low toxicity demonstrated in transgenic Xenopus laevis embryos, make mKate2 a superior fluorescent tag for imaging in living tissues. We also report tdKatushka2, a tandem far-red tag that performs well in fusions, provides 4-fold brighter near-IR fluorescence compared with mRaspberry or mCherry, and is 20-fold brighter than mPlum. Together, monomeric mKate2 and pseudo-monomeric tdKatushka2 represent the next generation of extra-bright far-red fluorescent probes offering novel possibilities for fluorescent imaging of proteins in living cells and animals.
authors.affiliation: Shemiakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, Moscow, Russia.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Shcherbo
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Murphy
authors.forename: Galina V
authors.initials: GV
authors.lastname: Ermakova
authors.forename: Elena A
authors.initials: EA
authors.lastname: Solovieva
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Chepurnykh
authors.forename: Aleksandr S
authors.initials: AS
authors.lastname: Shcheglov
authors.forename: Vladislav V
authors.initials: VV
authors.lastname: Verkhusha
authors.forename: Vladimir Z
authors.initials: VZ
authors.lastname: Pletnev
authors.forename: Kristin L
authors.initials: KL
authors.lastname: Hazelwood
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Roche
authors.forename: Sergey
authors.initials: S
authors.lastname: Lukyanov
authors.forename: Andrey G
authors.initials: AG
authors.lastname: Zaraisky
authors.forename: Michael W
authors.initials: MW
authors.lastname: Davidson
authors.forename: Dmitriy M
authors.initials: DM
authors.lastname: Chudakov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003952:Diagnostic Imaging / Q000379:methods; D004625:Embryo, Nonmammalian; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014982:Xenopus laevis; D000097573:Red Fluorescent Protein
chemical_list: D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein