Regulation of sulphate assimilation inSaccharomyces cerevisiae

Ono, Bun-ichiro; Kijima, Kazuyasu; Ishii, Nobuya; Kawato, Takahiro; Matsuda, Akio; Paszewski, Andrzej; Shinoda, Sumió

doi:10.1002/(sici)1097-0061(19960915)12:11<1153::aid-yea16>3.0.co;2-2

Cited by 33 publications

(2 citation statements)

References 36 publications

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“…In yeasts, where cysteine is exclusively synthesized through transsulfuration pathway (54), OAS solely serves as a coinducer of the sulfate assimilation pathway (55). In contrast, OAS serves as both a metabolic intermediate and a regulatory element in enteric bacteria (56).…”

Section: Functional Rescue Of the Yeast Cbs-deficient Mutant Strain Wmentioning

confidence: 99%

Characterization of Transsulfuration and Cysteine Biosynthetic Pathways in the Protozoan Hemoflagellate, Trypanosoma cruzi

Nozaki

Shigeta

Saito‐Nakano

et al. 2001

Journal of Biological Chemistry

102

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Sulfur-containing amino acids play an important role in a variety of cellular functions such as protein synthesis, methylation, and polyamine and glutathione synthesis. We cloned and characterized cDNA encoding cystathionine ␤-synthase (CBS), which is a key enzyme of transsulfuration pathway, from a hemoflagellate protozoan parasite Trypanosoma cruzi. T. cruzi CBS, unlike mammalian CBS, lacks the regulatory carboxyl terminus, does not contain heme, and is not activated by S-adenosylmethionine. T. cruzi CBS mRNA is expressed as at least six independent isotypes with sequence microheterogeneity from tandemly linked multicopy genes. The enzyme forms a homotetramer and, in addition to CBS activity, the enzyme has serine sulfhydrylase and cysteine synthase (CS) activities in vitro. Expression of the T. cruzi CBS in Saccharomyces cerevisiae and Escherichia coli demonstrates that the CBS and CS activities are functional in vivo. Enzymatic studies on T. cruzi extracts indicate that there is an additional CS enzyme and stage-specific control of CBS and CS expression. We also cloned and characterized cDNA encoding serine acetyltransferase (SAT), a key enzyme in the sulfate assimilatory cysteine biosynthetic pathway. Dissimilar to bacterial and plant SAT, a recombinant T. cruzi SAT showed allosteric inhibition by L-cysteine, L-cystine, and, to a lesser extent, glutathione. Together, these studies demonstrate the T. cruzi is a unique protist in possessing both transsulfuration and sulfur assimilatory pathways.Various sulfur compounds, especially cysteine, methionine, and S-adenosylmethionine, are essential for the growth and activities of all cells (1, 2). Methionine initiates the synthesis of proteins, whereas cysteine plays a critical role in the structure, stability, and catalytic function of many proteins. S-Adenosylmethionine plays a crucial role in methyl group transfer and in polyamine biosynthesis. Cysteine is also involved in the synthesis of the major antioxidant glutathione.In the filamentous fungi, Aspergillus nidulans and Neurospora crassa, the major route for the synthesis of cysteine is the condensation of O-acetylserine (OAS) 1 with sulfide, catalyzed by cysteine synthase (CS, OAS sulfhydrase) (3, 4). This pathway has been shown to be present in prokaryotes, plants, and enteric protozoan Entamoebae, and is generally called assimilatory cysteine biosynthetic pathway since this process involves reduction and fixation of inorganic sulfate to organic amino acids. Cysteine can also be synthesized by an alternative pathway: the sulfurylation of O-acetylhomoserine to give homocysteine, which then can be converted to cysteine via cystathionine by the transsulfuration pathway. In vertebrates, cysteine is synthesized from methionine via cystathionine by the transsulfuration pathway. This pathway is believed to be the sole route for cysteine synthesis in vertebrates with cystathionine ␤-synthase (CBS) acting as the flux-controlling enzyme (1). In mammals, this pathway also functions as catabolic pathway of methionine a...

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Section: Functional Rescue Of the Yeast Cbs-deficient Mutant Strain Wmentioning

confidence: 99%

Characterization of Transsulfuration and Cysteine Biosynthetic Pathways in the Protozoan Hemoflagellate, Trypanosoma cruzi

Nozaki

Shigeta

Saito‐Nakano

et al. 2001

Journal of Biological Chemistry

102

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“…Interestingly, the abundance of enzymes related to sulfate assimilation decreased after exposure to the zinc chelator DTPA (Table S3). The molecular mechanisms of sulfate assimilation are well described in yeast and filamentous fungi [71,72]. Didactically, the reactions can be subdivided into (i) the sulfate assimilation pathway, which culminates in the production of homocysteine, (ii) the transsulfuration pathway, which allows for cysteine synthesis, (iii) the methyl cycle, which includes the production of S-adenosylmethionine, and (iv) the glutathione biosynthesis pathway.…”

Section: Discussionmentioning

confidence: 99%

Zinc Starvation Induces Cell Wall Remodeling and Activates the Antioxidant Defense System in Fonsecaea pedrosoi

Santos,

Soares,

Oliveira

et al. 2024

JoF

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The survival of pathogenic fungi in the host after invasion depends on their ability to obtain nutrients, which include the transition metal zinc. This essential micronutrient is required to maintain the structure and function of various proteins and, therefore, plays a critical role in various biological processes. The host’s nutritional immunity limits the availability of zinc to pathogenic fungi mainly by the action of calprotectin, a component of neutrophil extracellular traps. Here we investigated the adaptive responses of Fonsecaea pedrosoi to zinc-limiting conditions. This black fungus is the main etiological agent of chromoblastomycosis, a chronic neglected tropical disease that affects subcutaneous tissues. Following exposure to a zinc-limited environment, F. pedrosoi induces a high-affinity zinc uptake machinery, composed of zinc transporters and the zincophore Pra1. A proteomic approach was used to define proteins regulated by zinc deprivation. Cell wall remodeling, changes in neutral lipids homeostasis, and activation of the antioxidant system were the main strategies for survival in the hostile environment. Furthermore, the downregulation of enzymes required for sulfate assimilation was evident. Together, the adaptive responses allow fungal growth and development and reveals molecules that may be related to fungal persistence in the host.

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Cysteine biosynthesis inSaccharomyces cerevisiae : a new outlook on pathway and regulation

Ono¹,

Hazu²,

Yoshida³

et al. 1999

Yeast

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Using a Saccharomyces cerevisiae strain having the activities of serine O‐acetyl‐transferase (SATase), O‐acetylserine/O‐acetylhomoserine sulphydrylase (OAS/OAH SHLase), cystathionine β‐synthase (β‐CTSase) and cystathionine γ‐lyase (γ‐CTLase), we individually disrupted CYS3(coding for γ‐CTLase) and CYS4 (coding for β‐CTSase). The obtained gene disruptants were cysteine‐dependent and incorporated the radioactivity of 35S‐sulphate into homocysteine but not into cysteine or glutathione. We concluded, therefore, that SATase and OAS/OAH SHLase do not constitute a cysteine biosynthetic pathway and that cysteine is synthesized exclusively through the pathway constituted with β‐CTSase and γ‐CTLase; note that OAS/OAH SHLase supplies homocysteine to this pathway by acting as OAH SHLase. From further investigation upon the cys3‐disruptant, we obtained results consistent with our earlier suggestion that cysteine and OAS play central roles in the regulation of sulphate assimilation. In addition, we found that sulphate transport activity was not induced at all in the cys4‐disruptant, suggesting that CYS4 plays a role in the regulation of sulphate assimilation. Copyright © 1999 John Wiley & Sons, Ltd.

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Regulation of sulphate assimilation inSaccharomyces cerevisiae

Cited by 33 publications

References 36 publications

Characterization of Transsulfuration and Cysteine Biosynthetic Pathways in the Protozoan Hemoflagellate, Trypanosoma cruzi

Characterization of Transsulfuration and Cysteine Biosynthetic Pathways in the Protozoan Hemoflagellate, Trypanosoma cruzi

Zinc Starvation Induces Cell Wall Remodeling and Activates the Antioxidant Defense System in Fonsecaea pedrosoi

Cysteine biosynthesis inSaccharomyces cerevisiae : a new outlook on pathway and regulation

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