OKOROKOV, LA and TANNER, W and LEHLE, L (1993) A NOVEL PRIMARY CA2+-TRANSPORT SYSTEM FROM SACCHAROMYCES-CEREVISIAE. EUROPEAN JOURNAL OF BIOCHEMISTRY, 216 (2). pp. 573-577. ISSN 0014-2956,
Full text not available from this repository.Abstract
A novel primary Ca2+-transport system in membranes from Saccharomyces cerevisiae is described. Ca2+ transport is strictly dependent on the presence of ATP; other nucleotides like GTP, UTP and CTP do not efficiently (< 10% of the rate of ATP) drive uptake. Transport is inhibited by sodium vanadate with an IC50 of 130 muM, but is insensitive to carbonylcyanide p-trifluoromethoxy-phenylhydrazone, valinomycin, gramicidin or calmodulin. Ca2+ accumulates in a free form and can be readily released by the Ca2+ ionophore A-23187 or by osmotic shock. The apparent K(m) values of transport activity for free Ca2+ was determined to be 0.11 muM and 5 muM for Mg . ATP, respectively. Taken together the results indicate that the Ca2+ transport described here does not belong to the plasma-membrane-type Ca2+-ATPase family but rather to the family of endomembrane-type ATPases. Cell-fractionation studies of crude membranes on sucrose gradient centrifugation have shown that the Ca2+-transport activity separates from marker enzymes for endoplasmic reticulum, vacuole, or plasma membrane and migrates with GDPase activity, a marker for the yeast Golgi complex.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PROTON-TRANSLOCATING ATPASE; VACUOLAR MEMBRANE; ENDOPLASMIC-RETICULUM; PLASMA-MEMBRANE; H+-ATPASE; MATING PHEROMONE; SCHIZOSACCHAROMYCES-POMBE; INTRACELLULAR CALCIUM; ALPHA-MANNOSIDASE; CA-2+ TRANSPORT; |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:42 |
| URI: | https://pred.uni-regensburg.de/id/eprint/53797 |
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