||Bacteria Escherichia coli
||Booth IR, Miller S, Müller A, Lehtovirta-Morley L. The evolution of bacterial mechanosensitive channels. Cell Calcium. 2015 Mar57(3):140-50. doi: 10.1016/j.ceca.2014.12.011. p.142 left column 2nd paragraphPubMed ID25591932
||P. Gangola, B.P. Rosen, Maintenance of intracellular calcium in Escherichia coli, J. Biol. Chem. 262 (1987) 12570–12574.PubMed ID2442165
||"Cells of E. coli were loaded with the membrane-permeable acetoxymethyl ester of fura-2, which was cleaved intracellularly to give the free pentaacid."
||"Bacterial Ca2+ pools of around 90 nM have
been measured in cells incubated with mM external Ca2+ [primary source].
Selective exclusion of Ca2+ must have arisen early in evolution,
given that it is desirable not to allow its penetration into the cytoplasm." Primary source abstract: "Recently a series of fluorescent calcium indicator dyes have been developed for measurement of free intracellular calcium in eukaryotic cells. Here [researchers] report the use of one such dye, fura-2, for the study of intracellular calcium levels in the prokaryote Escherichia coli. Cells of E. coli were loaded with the membrane-permeable acetoxymethyl ester of fura-2, which was cleaved intracellularly to give the free pentaacid. The concentration of free [Ca2+]i in unstarved cells was maintained at 90 +/- 10 nM, irrespective of the Ca2+ concentration in the extracellular medium."