Inhibition of amino acid transport and enhancement of tryptophan binding in a water mold by a range of natural and synthetic cytokinins
| Autor: | H.B. LéJohn, Roselynn M. W. Stevenson |
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| Rok vydání: | 1982 |
| Předmět: | |
| Zdroj: | Canadian Journal of Microbiology. 28:1165-1172 |
| ISSN: | 1480-3275 0008-4166 |
| Popis: | i temperature dependent. Only tryptophan uptake was anomalous, for while its transport was inhibited, its binding to a cell wall - membrane proteoglycan was stimulated severalfold. From kinetic studies, we deduced that the analogues and tryptophan were interacting with the same cell entity. Nucleoside forms of the analogues did not inhibit amino acid transport; this was understandable, since nucleosides are transported by an energy-linked system whereas nucleic acid bases are not. The purine analogues themselves were taken up very poorly by this organism. - . term "cytokininV which described, primarily, purine to promote the transport and mobilization of nutrients 1 analogues that enhance cytokinesis of plant cells in plants (Mothes and Engelbrecht 1961; Gunning and or tissues. Zeatin (6-(4-hydroxy-3-methylbut-2-enyl- Barkley 1963; Ilan 1971; Davies and Cocking 1967; amino)purine) , N6-isopentenyladenine (i6Ade), and Bhattachar~y a and ROY 1969; Nude1 and Bamberger tetrahydropyranylbenzylaminopurine (PBA) are three 197 1). The effect of c~tokinin on ~~cleoside uptake by of the few naturally occurring cytokinins. Kinetin ph~tohaemagglutinin-stimulated human lymphocytes (6-furfurylaminopurine) and benzyladenine, while they has been reported by Gallo and Whang-Peng (1971) have been isolated from plant tissues, are not unequiv- where i6~de inhibited uridine uptake. We had shown ocally established to be naturally occurring. earlier that i6~de inhibited the energy-linked transport of glucose (Goh and LCJohn 1978), nucleosides (Stev- 'Author to whom all correspondence should be addressed. enson and uJOhn 1978)3 and acids (Singh and 2Present address: Department of Microbiology, College of UJohn 1975) in the freshwater mold, Achl~a. This Biological Science, University of Guelph, Guelph, Ont., article is a detailed examination of the mode of amino Canada N1G 2W1. acid transport inhibition by i6~de and a number of other |
| Databáze: | OpenAIRE |
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