The PIR domain of Grb14 is an intrinsically unstructured protein: implication in insulin signaling

FEBS Lett. 2003 Nov 20;554(3):240-6. doi: 10.1016/s0014-5793(03)01095-0.

Abstract

Grb14 belongs to the Grb7 family of adapter proteins and was identified as a negative regulator of insulin signal transduction. Its inhibitory effect on the insulin receptor kinase activity is controlled by a newly discovered domain called PIR. To investigate the biochemical and biophysical characteristics of this new domain, we cloned and purified recombinant PIR-SH2, PIR, and SH2 domains. The isolated PIR and PIR-SH2 domains were physiologically active and inhibited insulin-induced reinitiation of meiosis in the Xenopus oocytes system. However, NMR experiments on (15)N-labelled PIR revealed that it did not present secondary structure. These results suggest that the PIR domain belongs to the growing family of intrinsically unstructured proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Insulin / physiology*
  • Meiosis / drug effects
  • Models, Molecular
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular / methods
  • Oocytes / drug effects
  • Oocytes / physiology
  • Phosphorylation
  • Protein Conformation
  • Protein Structure, Tertiary
  • Proteins / chemistry*
  • Proteins / genetics
  • Proteins / metabolism
  • Proteins / pharmacology
  • Receptor, Insulin / genetics
  • Receptor, Insulin / physiology*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Xenopus Proteins*
  • Xenopus laevis
  • src Homology Domains

Substances

  • Grb14 protein, Xenopus
  • Insulin
  • Nitrogen Isotopes
  • Proteins
  • Recombinant Fusion Proteins
  • Xenopus Proteins
  • Receptor, Insulin