The composition of Staufen-containing RNA granules from human cells indicates their role in the regulated transport and translation of messenger RNAs

Nucleic Acids Res. 2004 Apr 30;32(8):2411-20. doi: 10.1093/nar/gkh552. Print 2004.

Abstract

hStaufen is the human homolog of dmStaufen, a double-stranded (ds)RNA-binding protein involved in early development of the fly. hStaufen-containing complexes were purified by affinity chromatography from human cells transfected with a TAP-tagged hStaufen gene. These complexes showed a size >10 MDa. Untagged complexes with similar size were identified from differentiated human neuroblasts. The identity of proteins present in purified hStaufen complexes was determined by mass spectrometry and the presence of these proteins and other functionally related ones was verified by western blot. Ribosomes and proteins involved in the control of protein synthesis (PABP1 and FMRP) were present in purified hStaufen complexes, as well as elements of the cytoskeleton (tubulins, tau, actin and internexin), cytoskeleton control proteins (IQGAP1, cdc42 and rac1) and motor proteins (dynein, kinesin and myosin). In addition, proteins normally found in the nucleus, like nucleolin and RNA helicase A, were also found associated with cytosolic hStaufen complexes. The co-localization of these components with hStaufen granules in the dendrites of differentiated neuroblasts, determined by confocal immunofluorescence, validated their association in living cells. These results support the notion that the hStaufen-containing granules are structures essential in the localization and regulated translation of human mRNAs in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters
  • Biological Transport
  • Cell Line
  • Cytoplasmic Granules / chemistry*
  • Cytoskeletal Proteins / analysis
  • Histocompatibility Antigens Class I / genetics
  • Humans
  • Macromolecular Substances
  • Microtubule-Associated Proteins / analysis
  • Neurons / chemistry
  • Neurons / metabolism
  • Nuclear Proteins / analysis
  • Protein Biosynthesis
  • RNA / analysis*
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins / analysis*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / physiology*
  • Recombinant Fusion Proteins / isolation & purification
  • Recombinant Fusion Proteins / metabolism
  • Ribosomes / metabolism

Substances

  • ATP-Binding Cassette Transporters
  • Cytoskeletal Proteins
  • Histocompatibility Antigens Class I
  • Macromolecular Substances
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • RNA-Binding Proteins
  • Recombinant Fusion Proteins
  • STAU1 protein, human
  • staufen protein, mammalian
  • transporter associated with antigen processing (TAP)
  • RNA