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A GTP Hydrolase Activity Purified from Transitional Endoplasmic Reticulum of Rat Liver Binds Retinol

  • J. Zhao
  • D. M. Morré
Conference paper
Part of the NATO ASI Series book series (volume 74)

Abstract

GTP hydrolysis by an endoplasmic reticulum fraction from rat liver enriched in part-rough, part-smooth transition elements (transitional endoplasmic reticulum is inhibited by all-trans retinol (Zhao et al. 1990). The inhibition is non-competitive and the Km for GTP is 0.3 mM. The inhibitory effect is most apparent with GTP as substrate. Retinol did not significantly inhibit hydrolysis of the nucleoside diphosphates or of ATP or UTP. A GTP hydrolase enriched fraction from transitional endoplasmic reticulum of rat liver binds retinol. This protein may fulfill some role in mediating intracellular interactions, such as regulation of membrane traffic. GTP-binding proteins appear to be required for most vesicle formation-fusion events in eukaryotic secretory pathways (Bourne 1988). Within the cell, the transfer of materials from the endoplasmic reticulum to the Golgi apparatus occurs via transition vesicles. Retinol stimulates formation of transition vesicles, but not their fusion with the cis Golgi apparatus in a cell-free system from rat liver (Nowack et al. 1990). This study further characterizes the GTP hydrolase that is inhibited by retinol.

Keywords

Golgi Apparatus Membrane Traffic Endoplasmic Reticulum Fraction Transitional Endoplasmic Reticulum Transition Vesicle 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Bourne HR (1988) Do GTPases direct membrane traffic in secretion? Cell 53: 669–671PubMedCrossRefGoogle Scholar
  2. Morré DJ (1971) Isolation of Golgi apparatus. Method Enzymol 22: 130–148Google Scholar
  3. Nowack DD, Paulik M, Morré DJ, Morré DM (1990) Retinoid modulation of cell-free membrane transfer between endoplasmic reticulum and Golgi apparatus. Biochem Biophys Acta 1051: 250–258PubMedCrossRefGoogle Scholar
  4. Zhao J, Morré DJ, Paulik M, Yim J, Morré DM (1990) GTP hydrolysis by transitional endoplasmic reticulum from rat liver inhibited by all-trans retinol. Biochim Biophys Acta 1055: 230–233PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1993

Authors and Affiliations

  • J. Zhao
    • 1
  • D. M. Morré
    • 1
  1. 1.Department of Foods and NutritionPurdue UniversityWest LafayetteUSA

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