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Intra-Golgi transport inhibition by megalomicin

P Bonay1, S Munro, M Fresno

  • 1Centro de Biologi;a Molecular Severo Ochoa, Consejo Superior de Investigaciones Cienti;ficas-Universidad Autónoma de Madrid, Madrid 28049, Spain.

The Journal of Biological Chemistry
|February 16, 1996
PubMed

Insights

Megalomicin (MGM), a macrolide antibiotic, disrupts Golgi apparatus structure and function. This macrolide antibiotic impairs glycoprotein processing and sialylation by inhibiting intra-Golgi transport.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Pharmacology

Background:

  • Megalomicin (MGM) is a macrolide antibiotic known to cause anomalous glycosylation of viral proteins.
  • The Golgi apparatus is crucial for protein modification, including glycosylation and sialylation.

Purpose of the Study:

  • To investigate the effects of Megalomicin (MGM) on Golgi morphology and function.
  • To elucidate the mechanism by which MGM affects glycoprotein processing and sialylation.

Main Methods:

  • Immunofluorescence staining and electron microscopy to assess Golgi morphology.
  • Analysis of glycoprotein processing (sialylation) of viral and cellular proteins.
  • In vitro assays to measure glycosyltransferase activity and intra-Golgi transport.

Main Results:

  • Megalomicin (MGM) treatment caused significant dilation of the Golgi apparatus, particularly in the trans-Golgi network.
  • MGM impaired glycoprotein sialylation, leading to reduced sialylation on the cell surface.
  • MGM inhibited cis- to medial- and medial- to trans-Golgi transport of viral G protein in vitro, without affecting glycosyltransferase activity.

Conclusions:

  • Megalomicin (MGM) profoundly alters Golgi morphology and function.
  • The observed impairment in glycoprotein maturation is likely due to the inhibition of intra-Golgi transport by MGM.
  • MGM's effects on glycoprotein processing highlight its potential impact on cellular functions dependent on proper glycosylation.

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