The Interaction of Two Tethering Factors, p115 and COG Complex, Is Required for Golgi Integrity

Traffic. 2007 Mar;8(3):270-84. doi: 10.1111/j.1600-0854.2006.00530.x. Epub 2007 Jan 26.

Abstract

The vesicle-tethering protein p115 functions in endoplasmic reticulum-Golgi trafficking. We explored the function of homologous region 2 (HR2) of the p115 head domain that is highly homologous with the yeast counterpart, Uso1p. By expression of p115 mutants in p115 knockdown (KD) cells, we found that deletion of HR2 caused an irregular assembly of the Golgi, which consisted of a cluster of mini-stacked Golgi fragments, and gathered around microtubule-organizing center in a microtubule-dependent manner. Protein interaction analyses revealed that p115 HR2 interacted with Cog2, a subunit of the conserved oligomeric Golgi (COG) complex that is known another putative cis-Golgi vesicle-tethering factor. The interaction between p115 and Cog2 was found to be essential for Golgi ribbon reformation after the disruption of the ribbon by p115 KD or brefeldin A treatment and recovery by re-expression of p115 or drug wash out, respectively. The interaction occurred only in interphase cells and not in mitotic cells. These results strongly suggested that p115 plays an important role in the biogenesis and maintenance of the Golgi by interacting with the COG complex on the cis-Golgi in vesicular trafficking.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport / metabolism*
  • Brefeldin A / pharmacology
  • Endoplasmic Reticulum / metabolism
  • Golgi Apparatus / metabolism*
  • Golgi Matrix Proteins
  • HeLa Cells
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mutation
  • Protein Interaction Mapping
  • Protein Structure, Tertiary
  • Protein Synthesis Inhibitors / pharmacology
  • Protein Transport
  • SNARE Proteins / metabolism
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*

Substances

  • Adaptor Proteins, Vesicular Transport
  • Golgi Matrix Proteins
  • Membrane Proteins
  • Protein Synthesis Inhibitors
  • SNARE Proteins
  • Vesicular Transport Proteins
  • COG2 protein, human
  • vesicular transport factor p115
  • Brefeldin A