Site-specific fluorescent labeling to visualize membrane translocation of a myristoyl switch protein

Sci Rep. 2016 Sep 8:6:32866. doi: 10.1038/srep32866.

Abstract

Fluorescence approaches have been widely used for elucidating the dynamics of protein-membrane interactions in cells and model systems. However, non-specific multi-site fluorescent labeling often results in a loss of native structure and function, and single cysteine labeling is not feasible when native cysteines are required to support a protein's folding or catalytic activity. Here, we develop a method using genetic incorporation of non-natural amino acids and bio-orthogonal chemistry to site-specifically label with a single fluorescent small molecule or protein the myristoyl-switch protein recoverin, which is involved in rhodopsin-mediated signaling in mammalian visual sensory neurons. We demonstrate reversible Ca(2+)-responsive translocation of labeled recoverin to membranes and show that recoverin favors membranes with negative curvature and high lipid fluidity in complex heterogeneous membranes, which confers spatio-temporal control over down-stream signaling events. The site-specific orthogonal labeling technique is promising for structural, dynamical, and functional studies of many lipid-anchored membrane protein switches.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / genetics
  • Calcium / metabolism
  • Cell Membrane / metabolism*
  • Escherichia coli
  • Fluorescent Dyes / chemistry*
  • Fluorescent Dyes / pharmacokinetics
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Recoverin / genetics
  • Recoverin / metabolism*
  • Recoverin / pharmacokinetics
  • Red Fluorescent Protein
  • Spectrometry, Fluorescence / methods*

Substances

  • Amino Acids
  • Fluorescent Dyes
  • Luminescent Proteins
  • Recoverin
  • Calcium