Summary
-
1.
Tetrahymena thermophilia wild type inbred strain B 1863-III shows increased transport activity for a group of amino acids, corresponding to those ascribed to System L, after 5 h incubation in amino acid-free inorganic medium. This increase is abolished by cycloheximide. In contrast, no increased transport activity is observed in the mutant strain SB 1103.
-
2.
Kinetic analysis of influx indicates a significant increase in maximal velocity (J imax) with no change in substrate binding affinity (K t) by wild type cells and a loss of transport activity by mutant strain cells.
-
3.
Trans-stimulation cannot account for the starvation-induced enhancement of System L transport.
-
4.
Simultaneous determination of net flux from a mixture of 17 amino acids, using high performance liquid chromatography, indicates no net entry of substrate by unstarved controls of either strain. Starvation-induced enhancement of transport activity as well as net entry of substrate is observed in the wild type cells.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- BCH :
-
2-amino-bicyclo-[2, 2, 1]-heptane-2-carboxylic acid
References
Blum JJ (1982) Effects of cycloheximide and actinomycin D on the amino acid transport system ofTetrahymena. J Cell Physiol 111:104–110
Davis JP, Stephens GC (1984) Uptake of free amino acids by bacteria-free larvae of the sand dollarDendraster excentricus. Am J Physiol 16:R733-R739
Davis JP, Stephens GC (1983) Determination of net flux of 14 amino acids inTetrahymena pyriformis. J Comp Physiol 152:27–33
Gazzola GC, Franchi R, Saibene V, Ronchi P, Guidotti GG (1972) Regulation of amino acid transport in chick heart cells. I. Adaptive system of mediation for neutral amino acids. Biochim Biophys Acta 266:407–421
Guidotti GG, Borghetti AF, Gazzola GC (1978) The regulation of amino acid transport in animal cells. Biochim Biophys Acta 515:329–366
Hamburger K, Zeuthen E (1957) Synchronous divisions inTetrahymena pyriformis in an inorganic medium. Exp Cell Res 13:443–453
Hoffman EK, Rasmussen L (1972) Phenylalanine and methionine transport inTetrahymena pyriformis: Characteristics of a concentrating, inducible transport system. Biochim Biophys Acta 266:206–216
Kidder GW, Dewey UC (1951) The biochemistry of ciliates in pure culture. In: Lwoff A (ed) Biochemistry and physiology of protozoa, vol 1. Academic Press, New York, pp 323–400
Rasmussen L, Hoffman EK, Jorgensen GB (1978) Na+-independent uptake of nutrients inTetrahymena. J Comp Physiol 125:97–99
Rasmussen L, Orias E (1975)Tetrahymena: growth without phagocytosis. Science 190:464–465
Shotwell MA, Mattes JM, Jayme DW, Oxender DL (1982) Regulation of amino acid transport in Chinese hamster ovary cells. J Biol Chem 257:2974–2980
Shotwell MA, Kilberg MS, Oxender DL (1983) The regulation of neutral amino acid transport in mammalian cells. Biochim Biophys Acta 737:267–284
Stephens GC, Kerr NS (1962) Uptake of phenylalanine byTetrahymena pyriformis. Nature 194:1094–1095
Stoner LC, Dunhan PB (1970) Regulation of cellular osmolarity and volume inTetrahymena. J Exp Biol 53:391–399
Wheatley DN, Walker E (1980) Comparison of amino acid uptake and incorporation inTetrahymena pyriformis and HeLa cells. J Comp Physiol 140:267–274
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Davis, J.P., Stephens, G.C. Regulation of system L amino acid transport byTetrahymena thermophilia . J Comp Physiol B 156, 891–895 (1986). https://doi.org/10.1007/BF00694266
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00694266