Far-red fluorescent tags for protein imaging in living tissues.
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.
Shcherbo
Dmitry
D
Shemiakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, Moscow, Russia.
Murphy
Christopher S
CS
Ermakova
Galina V
GV
Solovieva
Elena A
EA
Chepurnykh
Tatiana V
TV
Shcheglov
Aleksandr S
AS
Verkhusha
Vladislav V
VV
Pletnev
Vladimir Z
VZ
Hazelwood
Kristin L
KL
Roche
Patrick M
PM
Lukyanov
Sergey
S
Zaraisky
Andrey G
AG
Davidson
Michael W
MW
Chudakov
Dmitriy M
DM
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
D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein