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Effects of Taurine on Calcium Ion Uptake and Protein Phosphorylation in Rat Retinal Membrane Preparations
Author(s) -
Lombardini J. B.
Publication year - 1985
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1985.tb05503.x
Subject(s) - taurine , phosphorylation , calcium , retinal , chemistry , membrane , biochemistry , protein phosphorylation , microbiology and biotechnology , biology , protein kinase a , amino acid , organic chemistry
The effects of taurine on ATP‐dependent calcium ion uptake and protein phosphorylation of rat retinal membrane preparations were investigated. Taurine (20 m M ) stimulates ATP‐dependent calcium ion uptake by twofold in crude retinal homogenates. In contrast, it inhibits the phosphorylation of specific membrane proteins as shown by acrylamide gel electrophoresis and autoradiography. The close structural analogue of taurine, 2‐aminoethylhydrogen sulfate, demonstrates similar effects in both systems, i.e., stimulation of ATP‐dependent calcium ion uptake and inhibition of protein phosphorylation, whereas isethionic acid and guanidinoethanesulfonate have no effect on either system. A P 1 subcellular fraction of the retinal membrane preparation that contains photoreceptor cell synaptosomes has a higher specific activity for the uptake of calcium ions. Phosphorylation of specific proteins in the P 1 fraction is also inhibited by the addition of 20 m M taurine. Taurine has no effect on retinal ATPase activities or on phosphatase activity, thus suggesting that it directly affects a kinase system.