Premium
Inositol 1,4,5‐trisphosphate releases Ca 2+ from vacuolar membrane vesicles of Saccharomyces cerevisiae
Author(s) -
Belde P.J.M.,
Vossen J.H.,
Borst-Pauwels G.W.F.H.,
Theuvenet A.P.R.
Publication year - 1993
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(93)81460-h
Subject(s) - inositol , endoplasmic reticulum , second messenger system , saccharomyces cerevisiae , vacuole , inositol trisphosphate , antiporter , vesicle , biochemistry , inositol trisphosphate receptor , intracellular , chemistry , calcium , ryanodine receptor , biophysics , yeast , biology , membrane , receptor , cytoplasm , organic chemistry
Inositol 1,4,5‐trisphosphate (IP 3 ) induces a release of Ca 2+ from vacuolar membrane vesicles of Saccharomyces cerevisiae . The amount released is dependent on IP 3 concentration (concentration for half maximal effect, K m apparent = 0.4 μM). Myo ‐inositol, and inositol 1,4‐bisphosphate up to 50 μM have no effect on Ca 2+ levels in the vesicles. The IP 3 ‐induced Ca 2+ release is blocked by dantrolene and 8‐( N , N ‐diethylamino)‐octyl 3,4,5‐trimethoxybenzoate‐HCl (TMB‐8), which are known to block Ca 2+ release from Ca 2+ stores in animal cells. IP 3 ‐induced release of Ca 2+ also occurs when Ca 2+ is accumulated by means of an artificial pH gradient, indicating that the effect of IP 3 is not due to an effect on the vacuolar H + ‐ATPase. The IP 3 ‐induced Ca 2+ release is not accompanied by a change in the pH gradient, which indicates that it is not due to a reversal of the Ca 2+ /nH + antiport or to a decrease in ΔpH by IP 3 . The present results suggest that IP 3 may act as a second messenger in the mobilization of Ca 2+ in yeast cells. As in plant cells, the vacuolar membrane of yeast seems to contain a Ca 2+ channel, which can be opened by IP 3 . In this respect the vacuole could function as an IP 3 ‐regulated intracellular Ca 2+ store, equivalent to the endoplasmic‐ and sarcoplasmic reticulum in animal cells, and play a role in Ca 2+ ‐dependent signal transduction in yeast cells.