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Caffeine, an inhibitor of endocytosis in dictyostelium discoideum amoebae
Author(s) -
Gonzalez Carlos,
Klein GéRard,
Satre Michel
Publication year - 1990
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041440307
Subject(s) - dictyostelium discoideum , endocytosis , caffeine , pinocytosis , extracellular , intracellular , axenic , biology , microbiology and biotechnology , dictyostelium , biochemistry , phagocytosis , secretion , calcium , chemistry , cell , bacteria , endocrinology , genetics , organic chemistry , gene
The effect of the trimethylxanthine, caffeine, was examined on the growth and endocytosis pathways of the vegetative amoebae of the cellular slime mold Dic‐tyostelium discoideum. Caffeine at concentrations of 1.5–3 mM was found to inhibit axenic growth, fluid‐phase pinocytosis, and secretion of lysosomal enzymes. Cell viability was unaffected by incubation for 16 hours with 5 mM caffeine but decreased markedly thereafter. Phagocytosis of the bacterium Esch‐erichia coli by Dictyostelium amoebae was also inhibited by caffeine, although at concentrations twofold to threefold higher. Caffeine rapidly entered into amoebae to reach an equilibrium between extracellular and intracellular concentrations, and it was not appreciably metabolized by Dictyostelium. Inhibition of growth and endocytosis was reversible upon removal of the drug and was partially counteracted by 10 mM adenosine. As caffeine discharged intracellular calcium stores in Dictyostelium (Abe et al., 1988), its inhibitory effect on endocytosis could result from the perturbation of calcium homeostasis. In agreement with this hypothesis, the cation La 3+ (10 μM), a Ca 2+ ‐transport inhibitor, also strongly reduced fluid‐phase pinocy'osis.