Glucocorticoid-dependent complementation of a hepatoma cell variant defective in viral glycoprotein sorting

Proc Natl Acad Sci U S A. 1988 Feb;85(3):797-801. doi: 10.1073/pnas.85.3.797.

Abstract

We have utilized the rat hepatoma (HTC) cell sorting variant CR4 to examine the glucocorticoid-regulated pathways that localize mouse mammary tumor virus glycoproteins to the cell surface. The defective sorting of cell surface mouse mammary tumor virus glycoproteins in CR4 cells was complemented after fusion with either normal rat hepatocytes or uninfected HTC cells. Indirect immunofluorescence of transient heterokaryons revealed that the regulated localization of mouse mammary tumor virus glycoproteins was dependent upon glucocorticoid treatment and required de novo RNA and protein synthesis. Thus, a glucocorticoid-regulated trafficking activity, unrelated to mouse mammary tumor virus sequences, which is induced in both adult rat liver and cultured hepatoma cells, can act in trans to mediate an intracellular sorting pathway for membrane glycoproteins.

Publication types

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

MeSH terms

  • Animals
  • Biological Transport
  • Cell Fusion
  • Dexamethasone / pharmacology*
  • Genetic Complementation Test
  • Glycoproteins / metabolism
  • Liver / cytology
  • Liver Neoplasms, Experimental / pathology*
  • Mammary Tumor Virus, Mouse / metabolism
  • Membrane Proteins / metabolism*
  • Protein Processing, Post-Translational / drug effects*
  • Rats
  • Retroviridae Proteins / metabolism*
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / metabolism

Substances

  • Glycoproteins
  • Membrane Proteins
  • Retroviridae Proteins
  • Dexamethasone