Nucleotide exchange on ARF mediated by yeast Gea1 protein

Nature. 1996 Dec 5;384(6608):479-81. doi: 10.1038/384479a0.


The ADP-ribosylation factor ARF is a small GTP-binding protein that is involved in the transport of vesicles between the endoplasmic reticulum (ER) and Golgi complex and within the Golgi complex itself. ARF cycles between inactive and membrane-associated active forms as a result of exchange of bound GDP for GTP; the GTP-bound form is an essential participant in the formation of transport vesicles. This nucleotide exchange is inhibited by the fungal metabolite brefeldin A (BFA). Here we identify a protein (Gea1) from Saccharomyces cerevisiae that is a component of a complex possessing guanine-nucleotide-exchange activity for ARF. We show that the activity of the complex is sensitive to brefeldin A and that Gea1 function is necessary for ER-Golgi transport in vivo. Gea1 contains a domain that is similar to a domain of Sec7, a protein necessary for intra-Golgi transport. We propose that Gea1 and ARNO, a human protein with a homologous Sec7 domain, are members of a new family of ARF guanine-nucleotide exchange factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-Ribosylation Factors
  • Biological Transport / genetics
  • Cloning, Molecular
  • Endoplasmic Reticulum / metabolism
  • Fungal Proteins / genetics
  • Fungal Proteins / isolation & purification
  • Fungal Proteins / metabolism*
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / metabolism*
  • Genes, Fungal
  • Golgi Apparatus / metabolism
  • Guanine Nucleotide Exchange Factors
  • Guanosine 5'-O-(3-Thiotriphosphate) / metabolism
  • Guanosine Triphosphate / metabolism
  • Humans
  • Molecular Sequence Data
  • Mutagenesis
  • Protein Binding
  • Proteins / genetics
  • Proteins / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins*


  • Fungal Proteins
  • GEA1 protein, S cerevisiae
  • Guanine Nucleotide Exchange Factors
  • Proteins
  • Saccharomyces cerevisiae Proteins
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • Guanosine Triphosphate
  • GTP-Binding Proteins
  • ADP-Ribosylation Factors

Associated data

  • PIR/S50437
  • PIR/S57049