An improved monomeric infrared fluorescent protein for neuronal and tumour brain imaging.
Infrared fluorescent proteins (IFPs) are ideal for in vivo imaging, and monomeric versions of these proteins can be advantageous as protein tags or for sensor development. In contrast to GFP, which requires only molecular oxygen for chromophore maturation, phytochrome-derived IFPs incorporate biliverdin (BV) as the chromophore. However, BV varies in concentration in different cells and organisms. Here we engineered cells to express the haeme oxygenase responsible for BV biosynthesis and a brighter monomeric IFP mutant (IFP2.0). Together, these tools improve the imaging capabilities of IFP2.0 compared with monomeric IFP1.4 and dimeric iRFP. By targeting IFP2.0 to the plasma membrane, we demonstrate robust labelling of neuronal processes in Drosophila larvae. We also show that this strategy improves the sensitivity when imaging brain tumours in whole mice. Our work shows promise in the application of IFPs for protein labelling and in vivo imaging.
1] Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, USA [2] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA.
Dan
D
Yu
Department of Pediatrics, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94158, USA.
William Clay
WC
Gustafson
1] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA [2] Department of Biophysics and Biochemistry, University of California, San Francisco, California 94158, USA [3] Department of Physiology, University of California, San Francisco, California 94158, USA.
Chun
C
Han
1] Université Grenoble Alpes, Institut de Biologie Structurale (IBS), Grenoble F-38000, France [2] CNRS, IBS, Grenoble F-38000, France [3] CEA, DSV, IBS, Grenoble F-38000, France.
Céline
C
Lafaye
1] Université Grenoble Alpes, Institut de Biologie Structurale (IBS), Grenoble F-38000, France [2] CNRS, IBS, Grenoble F-38000, France [3] CEA, DSV, IBS, Grenoble F-38000, France.
Marjolaine
M
Noirclerc-Savoye
1] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA [2] Department of Biophysics and Biochemistry, University of California, San Francisco, California 94158, USA [3] Department of Physiology, University of California, San Francisco, California 94158, USA.
Woo-Ping
WP
Ge
1] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA [2] Department of Biophysics and Biochemistry, University of California, San Francisco, California 94158, USA [3] Department of Physiology, University of California, San Francisco, California 94158, USA.
Desiree A
DA
Thayer
1] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA [2] Department of Biophysics and Biochemistry, University of California, San Francisco, California 94158, USA.
Hai
H
Huang
1] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA [2] Department of Biophysics and Biochemistry, University of California, San Francisco, California 94158, USA.
Thomas B
TB
Kornberg
1] Université Grenoble Alpes, Institut de Biologie Structurale (IBS), Grenoble F-38000, France [2] CNRS, IBS, Grenoble F-38000, France [3] CEA, DSV, IBS, Grenoble F-38000, France [4] European Synchrotron Radiation Facility, Grenoble F-38043, France.
Antoine
A
Royant
1] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA [2] Department of Biophysics and Biochemistry, University of California, San Francisco, California 94158, USA [3] Department of Physiology, University of California, San Francisco, California 94158, USA [4] Howard Hughes Medical Institute, University of California, San Francisco, California 94158, USA.
Lily Yeh
LY
Jan
1] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA [2] Department of Biophysics and Biochemistry, University of California, San Francisco, California 94158, USA [3] Department of Physiology, University of California, San Francisco, California 94158, USA [4] Howard Hughes Medical Institute, University of California, San Francisco, California 94158, USA.
Yuh Nung
YN
Jan
1] Department of Pediatrics, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94158, USA [2] Departments of Neurology and Neurosurgery, Brain Tumor Research Center, University of California, San Francisco, California 94158, USA.
William A
WA
Weiss
1] Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, USA [2] Cardiovascular Research Institute, University of California, San Francisco, California 94158, USA.
Xiaokun
X
Shu
D000818:Animals; D001664:Biliverdine / Q000378:metabolism; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D018360:Crystallography, X-Ray; D004330:Drosophila; D005456:Fluorescent Dyes / Q000378:metabolism*; D057809:HEK293 Cells; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D006801:Humans; D007259:Infrared Rays; D007814:Larva; D008164:Luminescent Proteins / Q000378:metabolism*; D051379:Mice; D018613:Microscopy, Confocal; D059906:Neuroimaging / Q000379:methods*; D009474:Neurons / Q000378:metabolism*; D010834:Phytochrome; D051381:Rats
D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D010834:Phytochrome; D006419:Heme Oxygenase (Decyclizing); D001664:Biliverdine