Identification of rabaptin-5, rabex-5, and GM130 as putative effectors of rab33b, a regulator of retrograde traffic between the Golgi apparatus and ER

FEBS Lett. 2001 Nov 16;508(2):201-9. doi: 10.1016/s0014-5793(01)02993-3.


The role of rab33b, a Golgi-specific rab protein, was investigated. Microinjection of rab33b mutants stabilised in the GTP-specific state resulted in a marked inhibition of anterograde transport within the Golgi and in the recycling of glycosyltransferases from the Golgi to the ER, respectively. A GST-rab33b fusion protein stabilised in its GTP form was found to interact by Western blotting or mass spectroscopy with Golgi protein GM130 and rabaptin-5 and rabex-5, two rab effector molecules thought to function exclusively in the endocytic pathway. A similar binding was seen to rab1 but not to rab6, both Golgi rabs. In contrast, rab5 was as expected, shown to bind rabaptin-5 and rabex-5 as well as the endosomal effector protein EEA1 but not GM130. No binding of EEA1 was seen to any of the Golgi rabs.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Autoantigens
  • Biological Transport, Active
  • Blotting, Western
  • Brain
  • Cattle
  • Cytosol / metabolism
  • Endoplasmic Reticulum / metabolism*
  • Golgi Apparatus / metabolism*
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Guanosine Triphosphate / metabolism
  • HeLa Cells
  • Humans
  • Intracellular Fluid / metabolism
  • Liver
  • Mass Spectrometry
  • Membrane Glycoproteins*
  • Membrane Proteins / metabolism*
  • Mutation
  • Precipitin Tests
  • Protein Binding
  • Protein Transport
  • Rats
  • Recombinant Fusion Proteins / metabolism
  • Vesicular Transport Proteins*
  • Viral Envelope Proteins / metabolism
  • rab GTP-Binding Proteins / genetics
  • rab GTP-Binding Proteins / metabolism*


  • Autoantigens
  • G protein, vesicular stomatitis virus
  • Golgin subfamily A member 2
  • Guanine Nucleotide Exchange Factors
  • Membrane Glycoproteins
  • Membrane Proteins
  • RABEP1 protein, human
  • RABGEF1 protein, human
  • Rabep1 protein, mouse
  • Recombinant Fusion Proteins
  • Vesicular Transport Proteins
  • Viral Envelope Proteins
  • Guanosine Triphosphate
  • RAB33B protein, human
  • rab GTP-Binding Proteins