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Calcium transport in the cellular slime mould Dictyostelium discoideum
Author(s) -
Europe-Finner G.N.,
Newell P.C.
Publication year - 1985
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(85)81341-7
Subject(s) - dictyostelium discoideum , chemotaxis , calcium , biophysics , stimulation , ouabain , biochemistry , microbiology and biotechnology , slime mold , mycetozoa , chemistry , biology , receptor , endocrinology , sodium , organic chemistry , gene
Transport of Ca 2+ into amoebae of Dictyostelium discoideum was studied using 45 Ca and a lanthanum stopping technique. Ca 2+ uptake was found to be rapid and showed saturation kinetics. No difference was found in Ca 2+ uptake between vegetative and aggregation competent cells, the V max for unstimulated amoebae being approx. 10 nmol/10 7 cells per min. Ca 2+ uptake had the characteristics of passive facilitated diffusion using a saturatable carrier and NaN 3 and ouabain were not inhibitory. The chemoattractants cAMP and folate, previously reported to stimulate the uptake of Ca 2+ into amoebae, did not stimulate the rate of Ca 2+ uptake by this carrier but increased the extent of Ca 2+ taken up over the period 10–30 s after chemotactic stimulation. The significance of these findings for the function of Ca 2+ in chemotactic signalling is discussed.