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. 1968 Nov;96(5):1574–1585. doi: 10.1128/jb.96.5.1574-1585.1968

Specificity and Control of Choline–O-Sulfate Transport in Filamentous Fungi

Nicole Bellenger a,1, Per Nissen a,2, Trudy C Wood a, Irwin H Segel a
PMCID: PMC315213  PMID: 5726299

Abstract

Choline-O-sulfate uptake by Penicillium notatum showed the following characteristics. (i) Transport was mediated by a permease which is highly specific for choline-O-sulfate. No significant inhibition of transport was caused by choline, choline-O-phosphate, acetylcholine, ethanolamine-O-phosphate, ethanolamine-O-sulfate, methanesulfonyl choline, 2-aminoethane thiosulfate, or the monomethyl or dimethyl analogues of choline-O-sulfate. Similarly, no significant inhibition was caused by any common sulfur amino acid or inorganic sulfur compound. Mutants lacking the inorganic sulfate permease possessed the choline-O-sulfate permease at wild-type levels. (ii) Choline-O-sulfate transport obeyed saturation kinetics (Km = 10−4 to 3 × 10−4m; Vmax = 1 to 6 μmoles per g per min). The kinetics of transport between 10−9 and 10−1m external choline-O-sulfate showed that only one saturable mechanism is present. (iii) Transport was sensitive to 2,4-dinitrophenol, azide, N-ethylmaleimide, p-chloromercuribenzoate, and cyanide. Ouabain, phloridzin, and eserine had no effect. (iv) Transport was pH-dependent with an optimum at pH 6. Variations in the ionic strength of the incubation medium had no effect. (v) Transport was temperature-dependent with a Q10 of greater than 2 between 3 and 40 C. Transport decreased rapidly above 40 C. (vi) Ethylenediaminetetraacetate (sodium salts, pH 6) had no effect, nor was there any stimulation by metal or nonmetal ions. Cu++, Ag+, and Hg++ were inhibitory. (vii) The initial rate at which the ester is transported was independent of intracellular hydrolysis. After long periods of incubation (> 10 min), a significant proportion of the transported choline-O-sulfate was hydrolyzed intracellulary. In the presence of 5 × 10−3m external choline-O-sulfate, the mycelia accumulated choline-O-sulfate to an apparent intracellular concentration of 0.075 m by 3 hr. Transport was unidirectional. No efflux or exchange of 35S-choline-O-sulfate was observed when preloaded mycelia were suspended in buffer alone or in buffer containing a large excess of unlabeled choline-O-sulfate. (viii) The specific transport activity of the mycelium depended on the sulfur source used for growth. (ix) Sulfur starvation of sulfur-sufficient mycelium resulted in an increase in the specific transport activity of the mycelium. This increase was prevented by cycloheximide, occurred only when a metabolizable carbon source was present, and resulted from an increase in the Vmax of the permease, rather than from a decrease in Km. The increase could be partially reversed by refeeding the mycelia with unlabeled choline-O-sulfate, sulfide, sulfite, l-homocysteine, l-cysteine, or compounds easily converted to cysteine. The results strongly suggested that the choline-O-sulfate permease is regulated primarily by repression-derepression, but that intracellular choline-O-sulfate and cysteine can act as feedback inhibitors.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. HARADA T., SPENCER B. Choline suphate in fungi. J Gen Microbiol. 1960 Apr;22:520–527. doi: 10.1099/00221287-22-2-520. [DOI] [PubMed] [Google Scholar]
  2. Hussey C., Orsi B. A., Scott J., Spencer B. Mechanism of choline sulphate utilization in fungi. Nature. 1965 Aug 7;207(997):632–634. doi: 10.1038/207632b0. [DOI] [PubMed] [Google Scholar]
  3. ITAHASHI M. Comparative biochemistry of choline sulfate metabolism. J Biochem. 1961 Jul;50:52–61. doi: 10.1093/oxfordjournals.jbchem.a127408. [DOI] [PubMed] [Google Scholar]
  4. KAJI A., McELROY W. D. Enzymic formation of choline sulfate. Biochim Biophys Acta. 1958 Oct;30(1):190–191. doi: 10.1016/0006-3002(58)90260-9. [DOI] [PubMed] [Google Scholar]
  5. Nissen P., Benson A. A. Choline Sulfate in Higher Plants. Science. 1961 Dec 1;134(3492):1759–1759. doi: 10.1126/science.134.3492.1759. [DOI] [PubMed] [Google Scholar]
  6. ORSI B. A., SPENCER B. CHOLINE SULPHOKINASE (SULPHOTRANSFERASE). J Biochem. 1964 Jul;56:81–91. doi: 10.1093/oxfordjournals.jbchem.a127963. [DOI] [PubMed] [Google Scholar]
  7. SEGAL I. H., JOHNSON M. J. Hydrolysis of choline-O-sulfate by cell-free extracts from Penicillium. Biochim Biophys Acta. 1963 Feb 5;69:433–434. doi: 10.1016/0006-3002(63)91287-3. [DOI] [PubMed] [Google Scholar]
  8. SEGEL I. H., JOHNSON M. J. Accumulation of intracellular inorganic sulfate by Penicillium chrysogenum. J Bacteriol. 1961 Jan;81:91–98. doi: 10.1128/jb.81.1.91-98.1961. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. SEGEL I. H., JOHNSON M. J. Synthesis and characterization of sodium cysteine-S-sulfate monohydrate. Anal Biochem. 1963 Apr;5:330–337. doi: 10.1016/0003-2697(63)90085-x. [DOI] [PubMed] [Google Scholar]
  10. TAKEBE I. Isolation and characterization of a new enzyme choline sulfatase. J Biochem. 1961 Sep;50:245–255. doi: 10.1093/oxfordjournals.jbchem.a127440. [DOI] [PubMed] [Google Scholar]
  11. Wiley W. R., Matchett W. H. Tryptophan transport in Neurospora crassa. II. Metabolic control. J Bacteriol. 1968 Mar;95(3):959–966. doi: 10.1128/jb.95.3.959-966.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Yamamoto L. A., Segel I. H. The inorganic sulfate transport system of Penicillium chrysogenum. Arch Biochem Biophys. 1966 Jun;114(3):523–538. doi: 10.1016/0003-9861(66)90376-6. [DOI] [PubMed] [Google Scholar]

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