Abstract
Pulses of a fluorinated analog of leucine, 5′,5′,5′-trifluoroleucine, reset the phase of the circadian rhythm of K+ uptake in Lemna gibba G3 under continuous light conditions. The trifluoroleucine pulse caused the largest delay phase-shifts during the early subjective phase but it caused only small phase advances. The action of trifluoroleucine was investigated and the following results were obtained. (a) The uptake of trifluoroleucine was essentially the same at all circadian phases, even though phase shifting was dramatically different at different phases. At effective phases, the magnitude of phase shifting was well correlated with the amount of trifluoroleucine taken up by the duckweed. (b) The trifluoroleucine pulse lowered the endogenous content of valine and leucine but these decreases did not correlate with phase shifting. (c) Protein synthesis was not affected by trifluoroleucine pulses which caused large phase shifts. (d) Pulses of 4-azaleucine, a different structural analog of leucine, also caused phase shifting. However, neither the direction nor the effective times of phase shifting were similar to those of trifluoroleucine. Taken together, these results negate the proposition that trifluoroleucine and azaleucine caused phase shift by disturbing amino acid metabolism and/or inhibiting protein synthesis, but they suggest instead that these analogs are incorporated into some protein(s) which are necessary for normal clock operation.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Alexander R. R., Calvo J. M., Freundlich M. Mutants of Salmonella typhimurium with an altered leucyl-transfer ribonucleic acid synthetase. J Bacteriol. 1971 Apr;106(1):213–220. doi: 10.1128/jb.106.1.213-220.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burgoyne R. D. A model for the molecular basis of circadian rhythm involving monovalent ion-mediated translational control. FEBS Lett. 1978 Oct 1;94(1):17–19. doi: 10.1016/0014-5793(78)80896-5. [DOI] [PubMed] [Google Scholar]
- Calvo J. M., Freundlich M., Umbarger H. E. Regulation of branched-chain amino acid biosynthesis in Salmonella typhimurium: isolation of regulatory mutants. J Bacteriol. 1969 Mar;97(3):1272–1282. doi: 10.1128/jb.97.3.1272-1282.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Datko A. H., Mudd S. H. Uptake of Amino Acids and Other Organic Compounds by Lemna paucicostata Hegelm. 6746. Plant Physiol. 1985 Mar;77(3):770–778. doi: 10.1104/pp.77.3.770. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Freundlich M., Trela J. M. Control of isoleucine, valine, and leucine biosynthesis. VI. Effect of 5',5',5'-trifluoroleucine on repression in Salmonella typhimurium. J Bacteriol. 1969 Jul;99(1):101–106. doi: 10.1128/jb.99.1.101-106.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grinde B., Seglen P. O. Effects of amino acid analogues on protein degradation in isolated rat hepatocytes. Biochim Biophys Acta. 1981 Aug 5;676(1):43–50. doi: 10.1016/0304-4165(81)90007-6. [DOI] [PubMed] [Google Scholar]
- Hartwig R., Schweiger M., Schweiger R., Schweiger H. G. Identification of a high molecular weight polypeptide that may be part of the circadian clockwork in Acetabularia. Proc Natl Acad Sci U S A. 1985 Oct;82(20):6899–6902. doi: 10.1073/pnas.82.20.6899. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kondo T. Phase Shift in the Potassium Uptake Rhythm of the Duckweed Lemna gibba G3 Caused by an Azide Pulse. Plant Physiol. 1983 Nov;73(3):605–608. doi: 10.1104/pp.73.3.605. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miflin B. J. Cooperative feedback control of barley acetohydroxyacid synthetase by leucine, isoleucine, and valine. Arch Biochem Biophys. 1971 Oct;146(2):542–550. doi: 10.1016/0003-9861(71)90159-7. [DOI] [PubMed] [Google Scholar]
- RENNERT O. M., ANKER H. S. ON THE INCORPORATION OF 5',5',5'-TRIFLUOROLEUCINE INTO PROTEINS OF E. COLI. Biochemistry. 1963 May-Jun;2:471–476. doi: 10.1021/bi00903a013. [DOI] [PubMed] [Google Scholar]
- Rothman B. S., Strumwasser F. Manipulation of a neuronal circadian oscillator with inhibitors of macromolecular synthesis. Fed Proc. 1977 Jun;36(7):2050–2055. [PubMed] [Google Scholar]
- SMITH S. S., BAYLISS N. L., MCCORD T. J. THE SYNTHESIS AND BIOLOGICAL ACTIVITIES OF SOME AZA ANALOGS OF AMINO ACIDS. I. 4-AZALEUCINE, AN INHIBITORY ANALOG OF LEUCINE. Arch Biochem Biophys. 1963 Aug;102:313–315. doi: 10.1016/0003-9861(63)90185-1. [DOI] [PubMed] [Google Scholar]
- Schweiger H. G., Schweiger M. Circadian rhythms in unicellular organisms: an endeavor to explain the molecular mechanism. Int Rev Cytol. 1977;51:315–342. doi: 10.1016/s0074-7696(08)60230-2. [DOI] [PubMed] [Google Scholar]
- Taylor W. R., Dunlap J. C., Hastings J. W. Inhibitors of protein synthesis on 80S ribosomes phase shift the Gonyaulax clock. J Exp Biol. 1982 Apr;97:121–136. doi: 10.1242/jeb.97.1.121. [DOI] [PubMed] [Google Scholar]
- Trela J. M., Freundlich M. Oncoupling of protein and ribonucleic acid synthesis by 5',5',5'-trifluoroleucine in Salmonella typhimurium. J Bacteriol. 1969 Jul;99(1):107–112. doi: 10.1128/jb.99.1.107-112.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Walz B., Sweeney B. M. Kinetics of the cycloheximide-induced phase changes in the biological clock in Gonyaulax. Proc Natl Acad Sci U S A. 1979 Dec;76(12):6443–6447. doi: 10.1073/pnas.76.12.6443. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winfree A. T. Unclocklike behaviour of biological clocks. Nature. 1975 Jan 31;253(5490):315–319. doi: 10.1038/253315a0. [DOI] [PubMed] [Google Scholar]
- Yeung S. J., Eskin A. Involvement of a specific protein in the regulation of a circadian rhythm in Aplysia eye. Proc Natl Acad Sci U S A. 1987 Jan;84(1):279–283. doi: 10.1073/pnas.84.1.279. [DOI] [PMC free article] [PubMed] [Google Scholar]