Effect of Aculeacin A, a Wall‐Active Antibiotic, on Synthesis of the Yeast Cell Wall

Yamaguchi, Hideyo; Hiratani, Takuo; Baba, Misuzu; Osumi, Masako

doi:10.1111/j.1348-0421.1985.tb00865.x

Cited by 41 publications

(23 citation statements)

References 24 publications

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“…Similar results were obtained with aculeacin A, another inhibitor of (1,3)-␤-D-glucan synthase (29), and with BE49385A, an inhibitor of Its8 fission yeast homolog of Mcd4 and Pig-n involved in glycosylphosphatidylinositol anchor synthesis (30) (data not shown).…”

Section: Resultssupporting

confidence: 69%

Phosphatidylinositol-4-phosphate 5-Kinase Regulates Fission Yeast Cell Integrity through a Phospholipase C-mediated Protein Kinase C-independent Pathway

Deng

Sugiura

Ohta

et al. 2005

Journal of Biological Chemistry

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Fission yeast its3-1 mutant is an allele of the essential gene its3؉ that encodes a phosphatidylinositol-4-phosphate 5-kinase (PIP5K) that produces phosphatidylinositol 4,5-bisphosphate. We found that the its3-1 mutant is sensitive to micafungin, a (1,3)-␤-D-glucan synthase inhibitor, suggesting a cell wall integrity defect. Consistently, its3-1 mutation caused synthetic lethality with a (1,3)-␤-Dglucan synthase mutant, bgs1-i2, and its3-1 mutant cells showed aberrant localization of green fluorescent protein-Bgs1. Similar aberrant localization of green fluorescent protein-tagged Rgf1, a putative phosphatidylinositol 4,5-bisphosphate-binding guanine nucleotide exchange factor for Rho protein, in its3-1 mutants was observed, suggesting a defective Rgf1/Rho pathway. To unravel the molecular mechanism(s), putative downstream components of PIP5K signaling were analyzed. Unexpectedly, overexpression of phospholipase C (Plc1), but not that of protein kinase C (PKC; Pck1 and Pck2), suppressed the phenotypes of the its3-1 mutant. These findings indicate that PKCs are not involved in the suppression, and further analysis revealed that PKCs are not downstream of Plc1 in fission yeast. Also, the enzymatic activity of Plc1 is essential for the suppression of the phenotypes and for the viability of the its3-1 mutant. These findings suggest that Its3 PIP5K regulates cell integrity through a Plc1-mediated PKC-independent pathway, in addition to the Rho/PKC pathway.

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Section: Resultssupporting

confidence: 69%

Phosphatidylinositol-4-phosphate 5-Kinase Regulates Fission Yeast Cell Integrity through a Phospholipase C-mediated Protein Kinase C-independent Pathway

Deng

Sugiura

Ohta

et al. 2005

Journal of Biological Chemistry

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“…Characterization of the enzyme activity from an S. cerevisiae wild-type strain and a mutant resistant to L-733,560 provides genetic evidence that glucan synthesis is the target in this yeast (21). Enzymatic activities from both strains were inhibited by L-733,560 in a dose-dependent fashion, but much higher concentrations were required to achieve 50% inhibition with crude microsomes from the mutant (IC50 of 50 ,uM for mutant versus 1 ,uM for the wild type [21] (44) reported on the inhibition (70%) of S. cerevisiae enzyme activity with aculeacin A at 1 ,ug/ml. They could not achieve a complete inhibition and, in fact, saw reduced levels of inhibition at higher concentrations which they attributed to the formation of insoluble micelles.…”

Section: Methodsmentioning

confidence: 94%

“…Since the intact fungal cell wall counteracts the high turgor pressure of the protoplast, an agent which disrupts cell wall integrity produces membrane swelling and 'ultimately causes lysis in the absence of osmotic support. Second, susceptible organisms undergo gross morphological changes after treatment with these agents, consistent with cell wall alterations (10,13,16,22,28,33,44). Third, whole-cell labeling experiments which monitor macromolecular synthesis demonstrate the preferential inhibition of cell wall synthesis (3, 13).…”

mentioning

confidence: 97%

Increased antifungal activity of L-733,560, a water-soluble, semisynthetic pneumocandin, is due to enhanced inhibition of cell wall synthesis

Kurtz

Douglas

Marrinan

et al. 1994

Antimicrob Agents Chemother

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The pneumocandins are natural lipopeptide products of the echinocandin class which inhibit the synthesis of 1,3-p-D-glucan in susceptible fungi. The lack of a corresponding pathway in mammalian hosts makes this mode of action an attractive one for treating systemic infections. Substitution by an aminoethyl ether at the hemiaminal and dehydration and reduction of the glutamine of pneumocandin Bo produced a semisynthetic compound (L-733,560) with intrinsic water solubility, significantly increased potency, and a broader antifungal spectrum. To evaluate the mechanism for the improved antifungal efficacy, we determined that L-733,560 was a more potent inhibitor of glucan synthase activity in vitro, did not affect the other membrane-bound enzymes tested, conferred susceptibility to lysis in the absence of osmotic support, and did not disrupt currents in liposomal bilayers or 86Rb+ fluxes from liposomes. In AspergiUus species L-733,560 also produced the same morphological alterations as pneumocandin Bo. A stereoisomer of L-733,560 with poor antifungal activity was a weak inhibitor of glucan synthase. All of these results support the notion that the enhanced antifungal activity of L-733,560 is achieved by superior inhibition of glucan synthesis and not by nonspecific membrane effects or a second mode of action.The echinocandins, pneumocandins, and papulacandins are antifungal agents which inhibit the synthesis of 1,3-,3-D-glucan in susceptible organisms (3,26,27,35,(38)(39)(40)42). Because the likelihood of mechanism-based toxicity is reduced, inhibition of the synthesis of a fungus-specific structure is an attractive mode of action for antifungal drug candidates. In addition to inhibition of in vitro glucan synthase activity, several observations on whole cells support the notion that these compounds act to inhibit cell wall synthesis in intact fungi. First, osmotic support prevents the lysis of cells treated with drug at the MICs (13, 45). Since the intact fungal cell wall counteracts the high turgor pressure of the protoplast, an agent which disrupts cell wall integrity produces membrane swelling and 'ultimately causes lysis in the absence of osmotic support. Second, susceptible organisms undergo gross morphological changes after treatment with these agents, consistent with cell wall alterations (10,13,16,22,28,33,44). Third, whole-cell labeling experiments which monitor macromolecular synthesis demonstrate the preferential inhibition of cell wall synthesis (3, 13). Lastly, Douglas et al. (21) recently showed that a mutation responsible for pneumocandin resistance in Saccharomyces cerevisiae cosegregates with enzyme activity resistant to inhibition by the pneumocandins.Originally, semisynthetic derivatives of the natural products were screened for reduced erythrocyte lysis, and this led to the development of the echinocandin B-based analog cilofungin (26,27 cantly alter the in vitro potency of the lipopeptide against Candida species compared with that of the natural product (17). Newer side chain analogs of the echi...

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“…This structure is considered by many to be a viable drug target (2,4,9). Drugs effective against cell wall components include the polyoxins (1), echinocandins (3), and aculeacins (6,11,12). Of the aculeacins, aculeacin A has been shown to be an effective inhibitor of P-glucan synthase (12), resulting in the production of osmotically sensitive cell walls (6, 11).…”

mentioning

confidence: 99%

“…Drugs effective against cell wall components include the polyoxins (1), echinocandins (3), and aculeacins (6,11,12). Of the aculeacins, aculeacin A has been shown to be an effective inhibitor of P-glucan synthase (12), resulting in the production of osmotically sensitive cell walls (6, 11). Currently, an echinocandin B derivative termed LY121019 (cilofungin) has been developed which shows good efficacy without many of the side effects of the polyenes (3).…”

mentioning

confidence: 99%

Use of Saccharomyces cerevisiae expressing beta-galactosidase to screen for antimycotic agents directed against yeast cell wall biosynthesis and possible application to pathogenic fungi

Zaworski¹,

Gill²

1990

Antimicrob Agents Chemother

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Saccharomyces cerevisiae expressing l-galactosidase was used to develop a screen for compounds active against formation of the yeast cell wall. The screen detailed here is based on the release of (-galactosidase from cells which had received an osmotic shock.Antifungal agents currently in use include polyene antibiotics (nystatin and amphotericin B), antimetabolites (flucytosine), imidazoles (clotrimazole, miconazole, and ketoconazole), griseofulvin, and other miscellaneous agents (10). Although these compounds are very effective against a wide range of fungi in vitro, many of these drugs have common targets in the host and pathogen which limit their application (7). For example, the polyene antibiotics nystatin and amophotericin B disrupt cell membrane function by binding to sterol components. Both yeast and mammalian cell membranes contain sterols, and thus toxicity of these drugs for host cells is a consideration. One of the salient differences between the yeasts and other fungi and mammalian cells is the presence of a thick rigid cell wall in yeast cells. This structure is considered by many to be a viable drug target (2,4,9). Drugs effective against cell wall components include the polyoxins (1), echinocandins (3), and aculeacins (6,11,12). Of the aculeacins, aculeacin A has been shown to be an effective inhibitor of P-glucan synthase (12), resulting in the production of osmotically sensitive cell walls (6, 11). Currently, an echinocandin B derivative termed LY121019 (cilofungin) has been developed which shows good efficacy without many of the side effects of the polyenes (3).The screen proposed here is based upon the sensitivity of the yeast cell to osmotic shock following drug treatment.

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Effect of Aculeacin A, a Wall‐Active Antibiotic, on Synthesis of the Yeast Cell Wall

Abstract: A wall-

Cited by 41 publications

References 24 publications

Phosphatidylinositol-4-phosphate 5-Kinase Regulates Fission Yeast Cell Integrity through a Phospholipase C-mediated Protein Kinase C-independent Pathway

Phosphatidylinositol-4-phosphate 5-Kinase Regulates Fission Yeast Cell Integrity through a Phospholipase C-mediated Protein Kinase C-independent Pathway

Increased antifungal activity of L-733,560, a water-soluble, semisynthetic pneumocandin, is due to enhanced inhibition of cell wall synthesis

Use of Saccharomyces cerevisiae expressing beta-galactosidase to screen for antimycotic agents directed against yeast cell wall biosynthesis and possible application to pathogenic fungi

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