Identification of two proteins that bind to a pyrimidine-rich sequence in the 3'-untranslated region of GAP-43 mRNA

Nucleic Acids Res. 1997 Mar 15;25(6):1281-8. doi: 10.1093/nar/25.6.1281.


GAP-43 is a membrane phosphoprotein that is important for the development and plasticity of neural connections. In undifferentiated PC12 pheochromocytoma cells, GAP-43 mRNA degrades rapidly ( t = 5 h), but becomes stable when cells are treated with nerve growth factor. To identify trans- acting factors that may influence mRNA stability, we combined column chromatography and gel mobility shift assays to isolate GAP-43 mRNA binding proteins from neonatal bovine brain tissue. This resulted in the isolation of two proteins that bind specifically and competitively to a pyrimidine-rich sequence in the 3'-untranslated region of GAP-43 mRNA. Partial amino acid sequencing revealed that one of the RNA binding proteins coincides with FBP (far upstream element binding protein), previously characterized as a protein that resembles hnRNP K and which binds to a single-stranded, pyrimidine-rich DNA sequence upstream of the c -myc gene to activate its expression. The other binding protein shares sequence homology with PTB, a polypyrimidine tract binding protein implicated in RNA splicing and regulation of translation initiation. The two proteins bind to a 26 nt pyrimidine-rich sequence lying 300 nt downstream of the end of the coding region, in an area shown by others to confer instability on a reporter mRNA in transient transfection assays. We therefore propose that FBP and the PTB-like protein may compete for binding at the same site to influence the stability of GAP-43 mRNA.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenal Gland Neoplasms
  • Amino Acid Sequence
  • Animals
  • Animals, Newborn
  • Base Sequence
  • Binding Sites
  • Brain / metabolism*
  • Cattle
  • Computer Simulation
  • GAP-43 Protein
  • Genes, myc
  • Humans
  • Membrane Glycoproteins / biosynthesis*
  • Mice
  • Models, Structural
  • Molecular Sequence Data
  • Nerve Tissue Proteins / biosynthesis*
  • PC12 Cells
  • Peptide Fragments / chemistry
  • Peptide Fragments / isolation & purification
  • Pheochromocytoma
  • Phosphoproteins / biosynthesis
  • RNA, Messenger / chemistry*
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / isolation & purification
  • RNA-Binding Proteins / metabolism*
  • Rats
  • Sequence Homology, Nucleic Acid


  • GAP-43 Protein
  • Membrane Glycoproteins
  • Nerve Tissue Proteins
  • Peptide Fragments
  • Phosphoproteins
  • RNA, Messenger
  • RNA-Binding Proteins