Summary
Tetrahymena pyriformis suspended in an inorganic medium accumulates3H-labelled taurine against a concentration gradient resulting in a cellular to extracellular taurine gradient of about 3 within 2 hours. This is observed in spite of the fact that taurine influx inTetrahymena via the saturable, Na1-dependent system and the leak pathway becomes gradually reduced with time after transfer to an inorganic, taurine free medium. Taurine is not accumulated byTetrahymena at pH below 7.0 or when protein synthesis is prevented by addition of cycloheximide. Addition of actinomycin D has no effect on the taurine accumulation. It is suggested that the transporter responsible for taurine accumulation inTetrahymena has a pH threshold of 7.0 and that translation but not transcription is conditional for the emergence of the transporter following transfer to inorganic medium. Taurine accumulation is reduced when the phosphatase inhibitor calyculin A is added at the initiation of starvation but unaffected when the inhibitor is added once the cells are in the inorganic medium. Addition of forskolin significantly enhances taurine accumulation. It is proposed that phosphorylation as well as dephosphorylation are involved in the regulation of taurine accumulation inTetrahymena pyriformis.
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Abbreviations
- AIB:
-
α-aminoisobutyric acid
- DMSO:
-
dimethyl sulfoxide
- GABA:
-
γ-aminobutyric acid
- HEPES:
-
N(2-hydroxyethyl)piperazine-N′-(2-ethanesulphonicacid)
- MOPS:
-
3-(N-morpholino) prop anesulphonicacid
- meAIB:
-
N-methylaminoisobutyric acid
- NMDG:
-
n-methyl-d-glucamonium
- TBAHS:
-
tetrabutylammonium hydrogensulfate
- TES:
-
N-Tris (hydroxymethyl)-methyl-2-amino ethane sulphonic acid
- TRIS:
-
Tris (hydroxymethyl) amino methane
References
Aomine M (1981) The amino acid absorption and transport in protozoa. Comp Biochem Physiol 68A: 531–540
Ballentine R, Burford DD (1960) Differential density separation of cellular suspensions. Anal Biochem 1: 263–268
Blum JJ (1982) Effects of cycloheximide and actinomycin D on the amino acid transport system ofTetrahymena. J Cell Physiol 111: 104–110
Crockett RL, Dunham PB, Rasmussen L (1965) Protein metabolism inTetrahymena pyriformis cells dividing synchronously under starvation conditions. Compt Rend Trav Lab Carlsberg 34: 451–486
Davis JP, Stephens GC (1983) Determination of net flux of 14 amino acids inTetrahymena pyriformis. J Comp Physiol 152: 27–33
Davis JP, Stephens GC (1986) Regulation of system L amino acid transport byTetrahymena thermophilia. J Comp Physiol 156B: 891–895
Dunham PB, Kropp DL (1973) Regulation of solutes and water in Tetrahymena. In: Elliot AM (ed) Biology ofTetrahymena. Dowden, Hutchinson, Ross, Inc., Stroudberg Pensylvania, pp 165–198
Hellung-Larsen P (1988) Parameters affecting the maximum cell concentration ofTetrahymena. Experientia 44: 58–60
Hoffmann EK, Kramhøft B (1969) A relationship between amino acid and sodium transport inTetrahymena pyriformis. Exp Cell Res 56: 265–268
Hoffmann EK, Rasmussen L (1972) Phenylalanine and methionine transport inTetrahymena pyriformis. Characteristics of a concentrating, inducible transport system. Biochem Biophys Acta 266: 206–216
Honkanen RE, Codispoti BA, Tse K, Boynton AL (1994) Characterization of natural toxins with inhibitory activity against serine/threonine protein phosphatases. Toxicon 32: 339–350
Huxtable RJ (1992) Physiological actions of taurine. Physiol Rev 72: 101–163
Jonassen TØ, Grinde B (1986) Proteolytic response to nutritional step-down inTetrahymena. Exp Cell Res 163: 165–174
Kramhøft B, Jessen F (1992) Acid extrusion by the ciliate protozoanTetrahymena pyriformis, and activation of a quiescent Na+/H+ exchanger by CuSO4. Cell Physiol Biochem 2: 8–17
Kramhøft B, Lambert IH (1997) Taurine transport systems in the ciliate protozoanTetrahymena pyriformis. Amino Acids 12: 57–75
Kromphardt H (1965) Zur pH-Abhängigkeit des Tranporters neutraler Aminosäuren in Ehrlich-Ascites-Tumorzellen. Biochem Z 343: 283–293
Lambert IH (1984) Na+-dependent taurine uptake in Ehrlich ascites tumour cells. Mol Physiol 6: 233–246
Lambert IH (1985) Taurine transport in Ehrlich ascites tumour cells: specificity and chloride dependence. Mol Physiol 7: 323–332
Lambert IH, Hoffmann EK (1993) Regulation of taurine transport in Ehrlich ascites tumor cells. J Membrane Biol 131: 67–79
Lambert IH, Hoffmann EK (1994) Cell swelling activates separate taurine and chloride channels in Ehrlich ascites tumor cells. J Membrane Biol 142: 289–298
Laurenza A, Sutkowski EM, Seamon KB (1989) Forskolin a specific stimulator of adenylate cyclase or a diterpene with multiple sites of action? TIPS Rev 10: 442–447
Mollerup J, Lambert IH (1996) Phosphorylation is involved in the regulation of the taurine influx via theβ-system in Ehrlich ascites tumor cells. J Membrane Biol 150: 73–82
Palfrey HC (1994) Protein phosphorylation control in the activity of volume-sensitive transport systems. In: Strange K (ed) Cellular and molecular physiology of cell volume regulation. CRC Press, Boca Raton, pp 201–214
Perret D (1986) Nucleotides, nucleosides and bases. In: Lim CK (ed) HPLC of small molecules — a practical approach. IRL Press limited, Oxford, England, pp 221–259
Ramanathan S, Chou SC (1973) Cyclic nucleotide phosphodiesterase fromTetrahymena. Comp Biochem Physiol 46B: 93–97
Strange K, Jackson PS (1995) Swelling-activated organic osmolyte efflux: new role for anion channels. Kidney Int 48: 994–1003
Wheatley DN, Walker E (1980) Comparison of amino acid uptake and incorporation inTetrahymena pyriformis and HeLa cells. J Comp Physiol 140: 267–274
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Kramhøft, B., Mollerup, J. & Lambert, I.H. Regulation of taurine accumulation in the ciliate protozoanTetrahymena pyriformis . Amino Acids 13, 281–297 (1997). https://doi.org/10.1007/BF01372593
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DOI: https://doi.org/10.1007/BF01372593