PUBLICATION

Modular transient nanoclustering of activated β2-adrenergic receptors revealed by single-molecule tracking of conformation-specific nanobodies

Authors
Gormal, R.S., Padmanabhan, P., Kasula, R., Bademosi, A.T., Coakley, S., Giacomotto, J., Blum, A., Joensuu, M., Wallis, T.P., Lo, H.P., Budnar, S., Rae, J., Ferguson, C., Bastiani, M., Thomas, W.G., Pardon, E., Steyaert, J., Yap, A.S., Goodhill, G.J., Hilliard, M.A., Parton, R.G., Meunier, F.A.
ID
ZDB-PUB-210126-1
Date
2020
Source
Proceedings of the National Academy of Sciences of the United States of America   117: 30476-30487 (Journal)
Registered Authors
Giacomotto, Jean, Parton, Robert G.
Keywords
nanobodies, single-particle−tracking superresolution microscopy, β2-adrenoreceptor
MeSH Terms
  • Animals
  • Cell Line
  • Endocytosis
  • Fluorescent Antibody Technique
  • Gene Expression
  • Genes, Reporter
  • Humans
  • Membrane Proteins/chemistry
  • Membrane Proteins/metabolism
  • Mice
  • Models, Molecular*
  • Protein Binding
  • Protein Conformation*
  • Receptors, Adrenergic, beta-2/chemistry*
  • Receptors, Adrenergic, beta-2/genetics
  • Receptors, Adrenergic, beta-2/metabolism
  • Recombinant Fusion Proteins
  • Single Molecule Imaging*/methods
  • Single-Domain Antibodies/chemistry*
  • Single-Domain Antibodies/metabolism
  • Zebrafish
PubMed
33214152 Full text @ Proc. Natl. Acad. Sci. USA
Abstract
None of the current superresolution microscopy techniques can reliably image the changes in endogenous protein nanoclustering dynamics associated with specific conformations in live cells. Single-domain nanobodies have been invaluable tools to isolate defined conformational states of proteins, and we reasoned that expressing these nanobodies coupled to single-molecule imaging-amenable tags could allow superresolution analysis of endogenous proteins in discrete conformational states. Here, we used anti-GFP nanobodies tagged with photoconvertible mEos expressed as intrabodies, as a proof-of-concept to perform single-particle tracking on a range of GFP proteins expressed in live cells, neurons, and small organisms. We next expressed highly specialized nanobodies that target conformation-specific endogenous β2-adrenoreceptor (β2-AR) in neurosecretory cells, unveiling real-time mobility behaviors of activated and inactivated endogenous conformers during agonist treatment in living cells. We showed that activated β2-AR (Nb80) is highly immobile and organized in nanoclusters. The Gαs-GPCR complex detected with Nb37 displayed higher mobility with surprisingly similar nanoclustering dynamics to that of Nb80. Activated conformers are highly sensitive to dynamin inhibition, suggesting selective targeting for endocytosis. Inactivated β2-AR (Nb60) molecules are also largely immobile but relatively less sensitive to endocytic blockade. Expression of single-domain nanobodies therefore provides a unique opportunity to capture highly transient changes in the dynamic nanoscale organization of endogenous proteins.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping