title: Proximity-dependent initiation of hybridization chain reaction.
abstract: Sensitive detection of protein interactions and post-translational modifications of native proteins is a challenge for research and diagnostic purposes. A method for this, which could be used in point-of-care devices and high-throughput screening, should be reliable, cost effective and robust. To achieve this, here we design a method (proxHCR) that combines the need for proximal binding with hybridization chain reaction (HCR) for signal amplification. When two oligonucleotide hairpins conjugated to antibodies bind in close proximity, they can be activated to reveal an initiator sequence. This starts a chain reaction of hybridization events between a pair of fluorophore-labelled oligonucleotide hairpins, generating a fluorescent product. In conclusion, we show the applicability of the proxHCR method for the detection of protein interactions and posttranslational modifications in microscopy and flow cytometry. As no enzymes are needed, proxHCR may be an inexpensive and robust alternative to proximity ligation assays.
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Koos
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Cane
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Grannas
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Liza
authors.initials: L
authors.lastname: Löf
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Linda
authors.initials: L
authors.lastname: Arngården
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Heldin
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Carl-Magnus
authors.initials: CM
authors.lastname: Clausson
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Axel
authors.initials: A
authors.lastname: Klaesson
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: M Karoliina
authors.initials: MK
authors.lastname: Hirvonen
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Felipe M S
authors.initials: FM
authors.lastname: de Oliveira
authors.affiliation: Department of Chemistry-BMC, Box 256, Uppsala University, SE-75123 Uppsala, Sweden.
authors.forename: Vladimir O
authors.initials: VO
authors.lastname: Talibov
authors.affiliation: School of Biological Sciences and School of Biomedical Sciences, University of Edinburgh, C H Waddington Building, Max Born Cresent, Kings Buildings, Edinburgh EH9 3BF, UK.
authors.forename: Nhan T
authors.initials: NT
authors.lastname: Pham
authors.affiliation: School of Biological Sciences and School of Biomedical Sciences, University of Edinburgh, C H Waddington Building, Max Born Cresent, Kings Buildings, Edinburgh EH9 3BF, UK.
authors.forename: Manfred
authors.initials: M
authors.lastname: Auer
authors.affiliation: Department of Chemistry-BMC, Box 256, Uppsala University, SE-75123 Uppsala, Sweden.
authors.forename: U Helena
authors.initials: UH
authors.lastname: Danielson
authors.affiliation: Institute of Pathology, Medical University of Graz, A-8036 Graz, Austria.
authors.forename: Johannes
authors.identifier: 0000000155183359
authors.initials: J
authors.lastname: Haybaeck
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Masood
authors.initials: M
authors.lastname: Kamali-Moghaddam
authors.affiliation: Uppsala University, Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Biomedical center, Husargatan 3, Box 815, SE-75108 Uppsala, Sweden.
authors.forename: Ola
authors.identifier: 0000000328831925
authors.initials: O
authors.lastname: Söderberg
mesh_terms: D004815:Epidermal Growth Factor / Q000737:chemistry; D066246:ErbB Receptors / Q000737:chemistry; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry*; D011485:Protein Binding
chemical_list: D005456:Fluorescent Dyes; D009841:Oligonucleotides; D004815:Epidermal Growth Factor; D066246:ErbB Receptors