Nuclear export and retention signals in the RS domain of SR proteins

Mol Cell Biol. 2002 Oct;22(19):6871-82. doi: 10.1128/mcb.22.19.6871-6882.2002.

Abstract

Splicing factors of the SR protein family share a modular structure consisting of one or two RNA recognition motifs (RRMs) and a C-terminal RS domain rich in arginine and serine residues. The RS domain, which is extensively phosphorylated, promotes protein-protein interactions and directs subcellular localization and-in certain situations-nucleocytoplasmic shuttling of individual SR proteins. We analyzed mutant versions of human SF2/ASF in which the natural RS repeats were replaced by RD or RE repeats and compared the splicing and subcellular localization properties of these proteins to those of SF2/ASF lacking the entire RS domain or possessing a minimal RS domain consisting of 10 consecutive RS dipeptides (RS10). In vitro splicing of a pre-mRNA that requires an RS domain could take place when the mutant RD, RE, or RS10 domain replaced the natural domain. The RS10 version of SF2/ASF shuttled between the nucleus and the cytoplasm in the same manner as the wild-type protein, suggesting that a tract of consecutive RS dipeptides, in conjunction with the RRMs of SF2/ASF, is necessary and sufficient to direct nucleocytoplasmic shuttling. However, the SR protein SC35 has two long stretches of RS repeats, yet it is not a shuttling protein. We demonstrate the presence of a dominant nuclear retention signal in the RS domain of SC35.

Publication types

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

MeSH terms

  • 3T3 Cells
  • Active Transport, Cell Nucleus / physiology
  • Animals
  • Cell Nucleus / metabolism*
  • Cell Nucleus / ultrastructure
  • Cytoplasm / metabolism
  • HeLa Cells
  • Heterogeneous-Nuclear Ribonucleoproteins
  • Humans
  • Mice
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism*
  • Organelles / metabolism
  • Phosphorylation
  • Protein Structure, Tertiary / physiology
  • RNA Splicing
  • RNA-Binding Proteins
  • Ribonucleoproteins / genetics
  • Ribonucleoproteins / metabolism
  • Sequence Homology, Amino Acid
  • Serine-Arginine Splicing Factors
  • Structure-Activity Relationship
  • Transfection

Substances

  • Heterogeneous-Nuclear Ribonucleoproteins
  • Nuclear Proteins
  • RNA-Binding Proteins
  • Ribonucleoproteins
  • SRSF2 protein, mouse
  • SRSF2 protein, human
  • Serine-Arginine Splicing Factors