Autoantigen Golgin-97, an effector of Arl1 GTPase, participates in traffic from the endosome to the trans-golgi network

Mol Biol Cell. 2004 Oct;15(10):4426-43. doi: 10.1091/mbc.e03-12-0872. Epub 2004 Jul 21.

Abstract

The precise cellular function of Arl1 and its effectors, the GRIP domain Golgins, is not resolved, despite our recent understanding that Arl1 regulates the membrane recruitment of these Golgins. In this report, we describe our functional study of Golgin-97. Using a Shiga toxin B fragment (STxB)-based in vitro transport assay, we demonstrated that Golgin-97 plays a role in transport from the endosome to the trans-Golgi network (TGN). The recombinant GRIP domain of Golgin-97 as well as antibodies against Golgin-97 inhibited the transport of STxB in vitro. Membrane-associated Golgin-97, but not its cytosolic pool, was required in the in vitro transport assay. The kinetic characterization of inhibition by anti-Golgin-97 antibody in comparison with anti-Syntaxin 16 antibody established that Golgin-97 acts before Syntaxin 16 in endosome-to-TGN transport. Knock down of Golgin-97 or Arl1 by their respective small interference RNAs (siRNAs) also significantly inhibited the transport of STxB to the Golgi in vivo. In siRNA-treated cells with reduced levels of Arl1, internalized STxB was instead distributed peripherally. Microinjection of Golgin-97 antibody led to the fragmentation of Golgi apparatus and the arrested transport to the Golgi of internalized Cholera toxin B fragment. We suggest that Golgin-97 may function as a tethering molecule in endosome-to-TGN retrograde traffic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-Ribosylation Factors / genetics
  • ADP-Ribosylation Factors / metabolism*
  • Animals
  • Antibodies / metabolism
  • Autoantigens / genetics
  • Autoantigens / metabolism*
  • Cell Line
  • Endosomes / metabolism*
  • Golgi Matrix Proteins
  • Humans
  • Membrane Fusion
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Microinjections
  • Protein Structure, Tertiary
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Protein Transport / physiology
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Rats
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Shiga Toxin 2 / genetics
  • Shiga Toxin 2 / metabolism
  • trans-Golgi Network / metabolism*

Substances

  • Antibodies
  • Autoantigens
  • Golgi Matrix Proteins
  • Golgi complex autoantigen, 97-kDa
  • Membrane Proteins
  • Protein Subunits
  • RNA, Small Interfering
  • Recombinant Fusion Proteins
  • Shiga Toxin 2
  • shiga toxin 2 B subunit
  • ADP-ribosylation factor related proteins
  • ADP-Ribosylation Factors