The coiled-coil membrane protein golgin-84 is a novel rab effector required for Golgi ribbon formation

J Cell Biol. 2003 Jan 20;160(2):201-12. doi: 10.1083/jcb.200207045. Epub 2003 Jan 21.

Abstract

Fragmentation of the mammalian Golgi apparatus during mitosis requires the phosphorylation of a specific subset of Golgi-associated proteins. We have used a biochemical approach to characterize these proteins and report here the identification of golgin-84 as a novel mitotic target. Using cryoelectron microscopy we could localize golgin-84 to the cis-Golgi network and found that it is enriched on tubules emanating from the lateral edges of, and often connecting, Golgi stacks. Golgin-84 binds to active rab1 but not cis-Golgi matrix proteins. Overexpression or depletion of golgin-84 results in fragmentation of the Golgi ribbon. Strikingly, the Golgi ribbon is converted into mini-stacks constituting only approximately 25% of the volume of a normal Golgi apparatus upon golgin-84 depletion. These mini-stacks are able to carry out protein transport, though with reduced efficiency compared with a normal Golgi apparatus. Our results suggest that golgin-84 plays a key role in the assembly and maintenance of the Golgi ribbon in mammalian cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoantigens*
  • Endoplasmic Reticulum / metabolism
  • Endoplasmic Reticulum / ultrastructure
  • Eukaryotic Cells / metabolism*
  • Eukaryotic Cells / ultrastructure
  • Gene Expression Regulation / physiology
  • Golgi Apparatus / metabolism*
  • Golgi Apparatus / ultrastructure
  • Golgi Matrix Proteins
  • HeLa Cells
  • Humans
  • Intracellular Membranes / metabolism*
  • Intracellular Membranes / ultrastructure
  • Membrane Proteins / metabolism*
  • Membrane Proteins / ultrastructure
  • Microscopy, Electron
  • Microtubule Proteins / metabolism*
  • Microtubule Proteins / ultrastructure
  • Mitosis / genetics
  • Phosphoproteins / metabolism
  • Protein Transport / genetics
  • RNA, Small Interfering
  • Rats
  • Recombinant Fusion Proteins
  • Subcellular Fractions
  • Vesicular Transport Proteins
  • Viral Proteins
  • rab1 GTP-Binding Proteins / metabolism*
  • rab1 GTP-Binding Proteins / ultrastructure

Substances

  • Autoantigens
  • GOLGA5 protein, human
  • Golgi Matrix Proteins
  • Membrane Proteins
  • Microtubule Proteins
  • Phosphoproteins
  • RNA, Small Interfering
  • Recombinant Fusion Proteins
  • Vesicular Transport Proteins
  • Viral Proteins
  • rab1 GTP-Binding Proteins