{"title":"Genetic system underlying responses of Cryptococcus neoformans to cadmium.","authors":"Akio Toh-E, Misako Ohkusu, Naruhiko Ishiwada, Akira Watanabe, Katsuhiko Kamei","doi":"10.1007/s00294-021-01222-y","DOIUrl":null,"url":null,"abstract":"<p><p>Cryptococcus neoformans, basidiomycetous pathogenic yeast, is basically an environmental fungus and, therefore, challenged by ever changing environments. In this study, we focused on how C. neoformans responds to stress caused by cadmium that is one of high-risk pollutants. By tracking phenotypes of the resistance or sensitivity to cadmium, we undertook forward and reverse genetic studies to identify genes involved in cadmium metabolism in C. neoformans. We found that the main route of Cd<sup>2+</sup> influx is through Mn<sup>2+</sup> ion transporter, Smf1, which is an ortholog of Nramp (natural resistance-associated macrophage protein 1) of mouse. We found that serotype A strains are generally more resistant to cadmium than serotype D strains and that cadmium resistance of H99, a representative of serotype A strains, was found to be due to a partial defect in SMF1. We found that calcium channel has a subsidiary role for cadmium uptake. We also showed that Pca1 (P-type-ATPase) functions as an extrusion pump for cadmium. We examined the effects of some metals on cadmium toxicity and suggested (i) that Ca<sup>2+</sup> and Zn<sup>2+</sup> could exert their protective function against Cd<sup>2+</sup> via restoring cadmium-inhibited cellular processes and (ii) that Mg<sup>2+</sup> and Mn<sup>2+</sup> could have antagonistic roles in an unknown Smf1-independent Cd<sup>2+</sup> uptake system. We proposed a model for Cd2<sup>+</sup>-response of C. neoformans, which will serve as a platform for understanding how this organism copes with the toxic metal.</p>","PeriodicalId":10918,"journal":{"name":"Current Genetics","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Current Genetics","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1007/s00294-021-01222-y","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/11/10 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"GENETICS & HEREDITY","Score":null,"Total":0}
引用次数: 2
Abstract
Cryptococcus neoformans, basidiomycetous pathogenic yeast, is basically an environmental fungus and, therefore, challenged by ever changing environments. In this study, we focused on how C. neoformans responds to stress caused by cadmium that is one of high-risk pollutants. By tracking phenotypes of the resistance or sensitivity to cadmium, we undertook forward and reverse genetic studies to identify genes involved in cadmium metabolism in C. neoformans. We found that the main route of Cd2+ influx is through Mn2+ ion transporter, Smf1, which is an ortholog of Nramp (natural resistance-associated macrophage protein 1) of mouse. We found that serotype A strains are generally more resistant to cadmium than serotype D strains and that cadmium resistance of H99, a representative of serotype A strains, was found to be due to a partial defect in SMF1. We found that calcium channel has a subsidiary role for cadmium uptake. We also showed that Pca1 (P-type-ATPase) functions as an extrusion pump for cadmium. We examined the effects of some metals on cadmium toxicity and suggested (i) that Ca2+ and Zn2+ could exert their protective function against Cd2+ via restoring cadmium-inhibited cellular processes and (ii) that Mg2+ and Mn2+ could have antagonistic roles in an unknown Smf1-independent Cd2+ uptake system. We proposed a model for Cd2+-response of C. neoformans, which will serve as a platform for understanding how this organism copes with the toxic metal.
期刊介绍:
Current Genetics publishes genetic, genomic, molecular and systems-level analysis of eukaryotic and prokaryotic microorganisms and cell organelles. All articles are peer-reviewed. The journal welcomes submissions employing any type of research approach, be it analytical (aiming at a better understanding), applied (aiming at practical applications), synthetic or theoretical.
Current Genetics no longer accepts manuscripts describing the genome sequence of mitochondria/chloroplast of a small number of species. Manuscripts covering sequence comparisons and analyses that include a large number of species will still be considered.