Comparative analysis of Cryptococcus neoformans acid-resistant particles generated from pigmented cells grown in different laccase substrates

Garcia-Rivera, Javier; Eisenman, Helene C.; Nosanchuk, Joshua D.; Aisen, Philip; Zaragoza, Óscar; Moadel, Tiffany; Dadachova, Ekaterina; Casadevall, Arturo

doi:10.1016/j.fgb.2005.09.003

Cited by 49 publications

(85 citation statements)

References 40 publications

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“…Recently, growing numbers of substrates for melanization in C. neoformans have been reported. These include several catecholamines, such as methyl-DOPA and norepinephrine (Garcia-Rivera et al, 2005). In addition, C. neoformans can use substrates produced by bacteria for melanization (Frases et al, 2006(Frases et al, , 2007.…”

Section: Discussionmentioning

confidence: 99%

“…The ghosts produced from C. neoformans cells grown in the presence of Lor D-DOPA were oxidized with acidic permanganate, as described previously (Garcia-Rivera et al, 2005). The oxidation products were analysed by HPLC using an Amersham Biosciences Ä KTAbasic liquid chromatograph with a P-900 pump, a UV-900 detector, and a Hamilton PRP-1 C 18 column with dimensions of 25064.1 mm, and particle size of 7 mm.…”

Section: Methodsmentioning

confidence: 99%

“…C. neoformans presumably melanizes during mammalian infection by scavenging substrates from tissue that remain unidentified (Rosas et al, 2000a). Recent reports have enumerated an expanded list of substrates that can be used for melanization in vitro, and these include several bacterial products (Frases et al, 2006(Frases et al, , 2007Garcia-Rivera et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

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Cryptococcus neoformans laccase catalyses melanin synthesis from both d- and l-DOPA

et al. 2007

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The human fungal pathogen Cryptococcus neoformans produces melanin in the presence of various substrates, including the L enantiomer of 3,4-dihydroxyphenylalanine (DOPA). The enzyme laccase catalyses the formation of melanin by oxidizing L-DOPA, initiating a series of presumably spontaneous reactions that ultimately leads to the polymerization of the pigment in the yeast cell wall. There, melanin protects the cell from a multitude of environmental and host assaults. Thus, the ability of C. neoformans to produce pigments from a variety of available substrates is likely to confer a survival advantage. A number of C. neoformans isolates of different serotypes produced pigments from D-DOPA, the stereoisomer of L-DOPA. Acid-resistant particles were isolated from pigmented C. neoformans cells grown in the presence of D-DOPA. Biophysical characterization showed the particles had a stably detectable free-radical signal by EPR, and negative zeta potential, similar to L-DOPA-derived particles. No major differences were found between L-and D-DOPA ghosts in terms of binding to anti-melanin antibodies, or in overall architecture when imaged by electron microscopy. C. neoformans cells utilized L-and D-DOPA at a similar rate. Overall, our results indicate that C. neoformans shows little stereoselectivity for utilizing DOPA in melanin synthesis. The ability of C. neoformans to use both L and D enantiomers for melanization implies that this organism has access to a greater potential pool of substrates for melanin synthesis, and this could potentially be exploited in the design of therapeutic inhibitors of laccase.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Cryptococcus neoformans laccase catalyses melanin synthesis from both d- and l-DOPA

et al. 2007

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“…Melanization protects C. neoformans from UV irradiation, oxidative stress and extreme temperatures Rosas & Casadevall, 1997;Wang & Casadevall, 1994). Melanization of C. neoformans depends on the presence of substrate, such as L-3,4-dihydroxyphenylalanine (L-DOPA) and other catecholamines (Garcia-Rivera et al, 2005). In addition, it requires expression of laccase, a cell wall enzyme that is associated with virulence (Zhu et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Vesicle-associated melanization in Cryptococcus neoformans

et al. 2009

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Recently, several pathogenic fungi were shown to produce extracellular vesicles that contain various components associated with virulence. In the human pathogenic fungus Cryptococcus neoformans, these components included laccase, an enzyme that catalyses melanin synthesis. Spherical melanin granules have been observed in the cell wall of C. neoformans. Given that melanin granules have dimensions that are comparable to those of extracellular vesicles, and that metazoan organisms produce melanin in vesicular structures known as melanosomes, we investigated the role of vesicles in cryptococcal melanization. Extracellular vesicles melanized when incubated with the melanin precursor L-3,4-dihydroxyphenylalanine (L-DOPA). The kinetics of substrate incorporation into cells and vesicles was analysed using radiolabelled L-DOPA. The results indicated that substrate incorporation was different for cells and isolated vesicles. Acidgenerated melanin ghosts stained with lipophilic dyes, implying the presence of associated lipid. A model for C. neoformans melanization is proposed that accounts for these observations and provides a mechanism for the assembly of melanin into relatively uniform spherical particles stacked in an orderly arrangement in the cell wall.

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“…Cryptococcus species complex cannot produce melanin pigment without certain exogenous substrates (Casadevall et al, 2003;Eisenman et al, 2011;Garcia-Rivera et al, 2005). Based on this idea, several modified culture media were developed for the rapid identification of Cryptococcus species complex, such as mustard seed, chili pepper, Pinus halepensis seed, Eggplant, benomyl bird seed and blackberry agar (Menezes et al, 2011;Mseddi et al, 2011;Nandhakumar et al, 2006;Pedroso et al, 2007;Pham et al, 2014;Sengul et al, 2014).…”

Section: Discussionmentioning

confidence: 99%

Development of Modified Selective Media to Differentiate Cryptococcus Species Complex and its Serotypes using Natural Materials

Park

Kim

et al. 2017

BSL

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The formation of brown colonies due to phenol oxidase activity on classic agar media containing natural material extracts of Helianthus annuus or on medium containing L-3,4-dihydroxyphenylalanine has been used to identify Cryptococcus species complex. In this study, various natural materials were used to develop a modified medium and to identify five major serotypes of Cryptococcus species complex. Serotypes A, D, and A/D were pigmented on medium using Perilla frutescens var. japonica Hara (PerJ agar) after a three-day incubation. Serotypes B and C were pigmented on PerJ agar after four-and five-day incubations, respectively. Growth time and pigmentation of the five serotypes occurred more rapidly on PerJ agar than on the other media. In addition, colony morphology, size, and pigmentation were specific by serotype. In conclusion, PerJ agar should be used in clinic settings to identify Cryptococcus species complex and its serotypes rapidly.

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Comparative analysis of Cryptococcus neoformans acid-resistant particles generated from pigmented cells grown in different laccase substrates

Cited by 49 publications

References 40 publications

Cryptococcus neoformans laccase catalyses melanin synthesis from both d- and l-DOPA

Cryptococcus neoformans laccase catalyses melanin synthesis from both d- and l-DOPA

Vesicle-associated melanization in Cryptococcus neoformans

Development of Modified Selective Media to Differentiate Cryptococcus Species Complex and its Serotypes using Natural Materials

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