Genetically encoded photoswitching of actin assembly through the Cdc42-WASP-Arp2/3 complex pathway

Proc Natl Acad Sci U S A. 2008 Sep 2;105(35):12797-802. doi: 10.1073/pnas.0801232105. Epub 2008 Aug 26.

Abstract

General methods to engineer genetically encoded, reversible, light-mediated control over protein function would be useful in many areas of biomedical research and technology. We describe a system that yields such photo-control over actin assembly. We fused the Rho family GTPase Cdc42 in its GDP-bound form to the photosensory domain of phytochrome B (PhyB) and fused the Cdc42 effector, the Wiskott-Aldrich Syndrome Protein (WASP), to the light-dependent PhyB-binding domain of phytochrome interacting factor 3 (Pif3). Upon red light illumination, the fusion proteins bind each other, activating WASP, and consequently stimulating actin assembly by the WASP target, the Arp2/3 complex. Binding and WASP activation are reversed by far-red illumination. Our approach, in which the biochemical specificity of the nucleotide switch in Cdc42 is overridden by the light-dependent PhyB-Pif3 interaction, should be generally applicable to other GTPase-effector pairs.

Publication types

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

MeSH terms

  • Actin-Related Protein 2-3 Complex / metabolism*
  • Actins / metabolism*
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins / metabolism
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Genetic Engineering*
  • Guanosine Diphosphate / metabolism
  • Light
  • Light Signal Transduction* / radiation effects
  • Phytochrome B / metabolism
  • Protein Binding
  • Wiskott-Aldrich Syndrome Protein / metabolism*
  • cdc42 GTP-Binding Protein / metabolism*

Substances

  • Actin-Related Protein 2-3 Complex
  • Actins
  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Transcription Factors
  • PIF3 protein, Arabidopsis
  • Wiskott-Aldrich Syndrome Protein
  • Phytochrome B
  • Guanosine Diphosphate
  • cdc42 GTP-Binding Protein