Calcium ionophores A23187 and X537A affect cell agglutination by lectins and capping of lymphocyte surface immunoglobulins

G. Poste, G. L. Nicolson

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

The microtubule-disruptive drugs colchicine and vinblastine alter ligand-induced redistribution of cell surface immunoglobulins and lectin receptors. These effects can be duplicated by treatment of cells with the divalent cation ionophores A23187 and X537A. Ionophore activity was dependent upon the presence of Ca2+ (1.8·10-3-4·10-4 M) in the culture medium. The K+-selective ionophore valinomycin had no effect on ligand-induced redistribution of surface receptors. It is suggested that A23187 and X537A impair membrane-associated microtubules involved in transmembrane control of receptor mobility and topography. In contrast to the action of colchicine and vinblastine that bind directly to microtubules, it is proposed that ionophores indirectly affect microtubules by raising the concentration of Ca2+ in the cytoplasm to levels that favor microtubule depolymerization and inhibit microtubule assembly.

Original languageEnglish (US)
Pages (from-to)148-155
Number of pages8
JournalBBA - Biomembranes
Volume426
Issue number1
DOIs
StatePublished - Feb 19 1976

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ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

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