Two motifs essential for nuclear import of the hnRNP A1 nucleocytoplasmic shuttling sequence M9 core

FEBS Lett. 2006 Feb 20;580(5):1365-70. doi: 10.1016/j.febslet.2006.01.058. Epub 2006 Jan 26.

Abstract

Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 regulates mRNA genesis. It shuttles between the nucleus and cytoplasm. Its shuttling signal is a 38-residue sequence M9. We studied the nuclear import and export of M9 by mutational analysis. Heterokaryon assay indicated that the 19-residue sequence SNFGPMKGGNFGGRSSGPY (M9 core) is necessary and sufficient for shuttling. Moreover, M9 core mutation revealed that in addition to the hitherto characterized N-terminal motif SNFGPMK, the C-terminal motif PY is crucial for nuclear import as well as for binding to transportin. Key residues of the motifs are conserved in the shuttling signals of hnRNP D and JKTBP.

MeSH terms

  • Active Transport, Cell Nucleus*
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Conserved Sequence
  • HeLa Cells
  • Heterogeneous Nuclear Ribonucleoprotein A1
  • Heterogeneous-Nuclear Ribonucleoprotein Group A-B / chemistry*
  • Heterogeneous-Nuclear Ribonucleoprotein Group A-B / genetics
  • Heterogeneous-Nuclear Ribonucleoprotein Group A-B / metabolism
  • Humans
  • Hybrid Cells
  • Karyopherins / metabolism
  • Mice
  • Mutation
  • Peptide Fragments
  • Protein Sorting Signals*

Substances

  • Heterogeneous Nuclear Ribonucleoprotein A1
  • Heterogeneous-Nuclear Ribonucleoprotein Group A-B
  • Karyopherins
  • M9 nuclear localization signal peptide
  • Peptide Fragments
  • Protein Sorting Signals