GTP-bound forms of rab6 induce the redistribution of Golgi proteins into the endoplasmic reticulum

Proc Natl Acad Sci U S A. 1997 Mar 4;94(5):1828-33. doi: 10.1073/pnas.94.5.1828.

Abstract

rab6 is a ubiquitous ras-like GTPase involved in intra-Golgi transport. We have studied at both morphological and biochemical levels the behavior of Golgi resident proteins in HeLa cells overexpressing wild-type rab6 and GTP- and GDP-bound mutants of rab6 (rab6 Q72L and rab6 T27N, respectively). We show that wild-type rab6 and rab6 Q72L overexpression induces the redistribution of the trans-Golgi protein beta-1,4-galactosyltransferase into the endoplasmic reticulum (ER) and allows the addition of sialylated O-glycans on an ER-retained protein, the major histocompatibility complex class II-associated invariant chain. Remarkably, rab6 Q72L effects, which require the integrity of microtubules, were almost indistinguishable from those induced by brefeldin A, a fungic metabolite that causes a mixing of Golgi and ER membranes. In contrast, overexpression of rab6 T27N does not cause the redistribution of Golgi proteins, but inhibits basal O-glycosylation of the major histocompatibility complex class II-associated invariant chain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antigens, Differentiation, B-Lymphocyte / metabolism*
  • Biomarkers
  • Brefeldin A
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cyclopentanes / pharmacology
  • Endoplasmic Reticulum / metabolism*
  • Fluorescent Antibody Technique
  • Gene Expression Regulation / genetics
  • Glycosylation
  • Golgi Apparatus / enzymology
  • Golgi Apparatus / metabolism*
  • Guanosine Diphosphate / metabolism
  • Guanosine Triphosphate / metabolism*
  • HeLa Cells
  • Histocompatibility Antigens Class II / metabolism*
  • Humans
  • Lectins / metabolism
  • Microtubules / metabolism
  • Molecular Sequence Data
  • N-Acetyllactosamine Synthase / metabolism*
  • Plant Lectins*
  • Transfection / genetics
  • rab GTP-Binding Proteins*
  • ras Proteins / genetics
  • ras Proteins / metabolism*

Substances

  • Antigens, Differentiation, B-Lymphocyte
  • Biomarkers
  • Carrier Proteins
  • Cyclopentanes
  • Histocompatibility Antigens Class II
  • Lectins
  • Plant Lectins
  • Rab6 protein
  • invariant chain
  • jacalin
  • Guanosine Diphosphate
  • Brefeldin A
  • Guanosine Triphosphate
  • N-Acetyllactosamine Synthase
  • rab GTP-Binding Proteins
  • ras Proteins