title: A split horseradish peroxidase for the detection of intercellular protein-protein interactions and sensitive visualization of synapses.
abstract: Intercellular protein-protein interactions (PPIs) enable communication between cells in diverse biological processes, including cell proliferation, immune responses, infection, and synaptic transmission, but they are challenging to visualize because existing techniques have insufficient sensitivity and/or specificity. Here we report a split horseradish peroxidase (sHRP) as a sensitive and specific tool for the detection of intercellular PPIs. The two sHRP fragments, engineered through screening of 17 cut sites in HRP followed by directed evolution, reconstitute into an active form when driven together by an intercellular PPI, producing bright fluorescence or contrast for electron microscopy. Fusing the sHRP fragments to the proteins neurexin (NRX) and neuroligin (NLG), which bind each other across the synaptic cleft, enabled sensitive visualization of synapses between specific sets of neurons, including two classes of synapses in the mouse visual system. sHRP should be widely applicable to studying mechanisms of communication between a variety of cell types.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Martell
authors.affiliation: Department of Molecular and Cellular Biology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Masahito
authors.identifier: 0000-0001-8193-2931
authors.initials: M
authors.lastname: Yamagata
authors.affiliation: National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, University of California at San Diego, La Jolla, San Diego, California, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Deerinck
authors.affiliation: National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, University of California at San Diego, La Jolla, San Diego, California, USA.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Phan
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Carolyn G
authors.initials: CG
authors.lastname: Kwa
authors.affiliation: National Center for Microscopy and Imaging Research, Center for Research on Biological Systems, University of California at San Diego, La Jolla, San Diego, California, USA.|Department of Neurosciences, University of California at San Diego, La Jolla, San Diego, California, USA.|Salk Institute for Biological Studies, La Jolla, San Diego, California, USA.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Ellisman
authors.affiliation: Department of Molecular and Cellular Biology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Sanes
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Ting
mesh_terms: D000818:Animals; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics*; D051379:Mice; D008854:Microscopy, Electron / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D015202:Protein Engineering / Q000379:methods; D025941:Protein Interaction Mapping / Q000379:methods*; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure*
chemical_list: D009419:Nerve Tissue Proteins; D006735:Horseradish Peroxidase