Identification of ribosome-binding protein p34 as an intracellular protein that binds acidic fibroblast growth factor

J Biol Chem. 2002 Jun 28;277(26):23864-71. doi: 10.1074/jbc.M112193200. Epub 2002 Apr 18.

Abstract

With the aim of identifying new intracellular binding partners for acidic fibroblast growth factor (aFGF), proteins from U2OS human osteosarcoma cells were adsorbed to immobilized aFGF. One of the adsorbed proteins is a member of the leucine-rich repeat protein family termed ribosome-binding protein p34 (p34). This protein has previously been localized to endoplasmic reticulum membranes and is thought to span the membrane with the N terminus on the cytosolic side. Confocal microscopy of cells transfected with Myc-p34 confirmed the endoplasmic reticulum localization, and Northern blotting determined p34 mRNA to be present in a multitude of different tissues. Cross-linking experiments indicated that the protein is present in the cell as a dimer. In vitro translated p34 was found to interact with maltose-binding protein-aFGF through its cytosolic coiled-coil domain. The interaction between aFGF and p34 was further characterized by surface plasmon resonance, giving a K(D) of 1.4 +/- 0.3 microm. Even though p34 interacted with mitogenic aFGF, it bound poorly to the non-mitogenic aFGF(K132E) mutant, indicating a possible involvement of p34 in intracellular signaling by aFGF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • COS Cells
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Dimerization
  • Fibroblast Growth Factor 1 / genetics
  • Fibroblast Growth Factor 1 / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Mass Spectrometry
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • RNA, Messenger / analysis
  • Structure-Activity Relationship

Substances

  • Carrier Proteins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • RNA, Messenger
  • ribosome-binding protein p34, human
  • Fibroblast Growth Factor 1