Proteogenomics analysis of CUG codon translation in the human pathogen Candida albicans

AbstractCandida yeasts causing human infections are spread across the yeast phylum with Candida glabrata being related to Saccharomyces cerevisiae, Candida krusei grouping to Pichia spp., and Candida albicans, Candida parapsilosis and Candida tropicalis belonging to the CTG-clade. The latter lineage contains yeasts with an altered genetic code translating CUG codons as serine using a serine-tRNA with a mutated anticodon. It has been suggested that the CTG-clade CUG codons are mistranslated to a small extent as leucine due to mischarging of the serine-tRNA(CAG). The mistranslation was suggested to result in variable surface proteins explaining fast host adaptation and pathogenicity. Here, we re-assessed this potential mistranslation by high-resolution mass spectrometry-based proteogenomics of multiple CTG-clade yeasts, various C. albicans strains, isolated from colonized and from infected human body sites, and C. albicans grown in yeast and hyphal forms. Our in vivo data do not support CUG codon mistranslation by leucine. Instead, (i) CUG codons are mistranslated only to the extent of ribosomal mistranslation with no preference for specific amino acids, (ii) CUG codons are as unambiguous (or ambiguous) as the related CUU leucine and UCC serine codons, (iii) tRNA anticodon loop variation across the CTG-clade yeasts does not result in any difference of the mistranslation level, and (iv) CUG codon unambiguity is independent of C. albicans’ strain pathogenicity or growth form.

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Proteogenomics analysis of CUG codon translation in the human pathogen Candida albicans

BMC Biology ◽

10.1186/s12915-021-01197-9 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Stefanie Mühlhausen ◽

Hans Dieter Schmitt ◽

Uwe Plessmann ◽

Peter Mienkus ◽

Pia Sternisek ◽

...

Keyword(s):

Candida Albicans ◽

Growth Form ◽

Candida Parapsilosis ◽

Trna Gene ◽

High Resolution Mass Spectrometry ◽

Phenotypic Diversity ◽

Surface Proteins ◽

Variable Surface ◽

Serine Codons ◽

Human Pathogen Candida Albicans

Abstract Background Yeasts of the CTG-clade lineage, which includes the human-infecting Candida albicans, Candida parapsilosis and Candida tropicalis species, are characterized by an altered genetic code. Instead of translating CUG codons as leucine, as happens in most eukaryotes, these yeasts, whose ancestors are thought to have lost the relevant leucine-tRNA gene, translate CUG codons as serine using a serine-tRNA with a mutated anticodon, $$ {\mathrm{tRNA}}_{\mathrm{CAG}}^{\mathrm{Ser}} $$ tRNA CAG Ser . Previously reported experiments have suggested that 3–5% of the CTG-clade CUG codons are mistranslated as leucine due to mischarging of the $$ {\mathrm{tRNA}}_{\mathrm{CAG}}^{\mathrm{Ser}} $$ tRNA CAG Ser . The mistranslation was suggested to result in variable surface proteins explaining fast host adaptation and pathogenicity. Results In this study, we reassess this potential mistranslation by high-resolution mass spectrometry-based proteogenomics of multiple CTG-clade yeasts, including various C. albicans strains, isolated from colonized and from infected human body sites, and C. albicans grown in yeast and hyphal forms. Our data do not support a bias towards CUG codon mistranslation as leucine. Instead, our data suggest that (i) CUG codons are mistranslated at a frequency corresponding to the normal extent of ribosomal mistranslation with no preference for specific amino acids, (ii) CUG codons are as unambiguous (or ambiguous) as the related CUU leucine and UCC serine codons, (iii) tRNA anticodon loop variation across the CTG-clade yeasts does not result in any difference of the mistranslation level, and (iv) CUG codon unambiguity is independent of C. albicans’ strain pathogenicity or growth form. Conclusions Our findings imply that C. albicans does not decode CUG ambiguously. This suggests that the proposed misleucylation of the $$ {\mathrm{tRNA}}_{\mathrm{CAG}}^{\mathrm{Ser}} $$ tRNA CAG Ser might be as prevalent as every other misacylation or mistranslation event and, if at all, be just one of many reasons causing phenotypic diversity.

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Evaluation of the immunodiagnostic potential of a recombinant surface protein domain fromAcanthamoeba castellanii

Parasitology ◽

10.1017/s0031182016001281 ◽

2016 ◽

Vol 143 (12) ◽

pp. 1656-1664 ◽

Cited By ~ 4

Author(s):

ALEMAO G. CARPINTEYRO SÁNCHEZ ◽

VERIDIANA GOMES VIRGINIO ◽

VINICIUS JOSÉ MASCHIO ◽

HENRIQUE BUNSELMEYER FERREIRA ◽

MARILISE BRITTES ROTT

Keyword(s):

Acanthamoeba Castellanii ◽

Surface Protein ◽

Skin Lesions ◽

Surface Proteins ◽

Protein Domain ◽

Recombinant Polypeptide ◽

Diagnostic Potential ◽

Human Sera ◽

Human Infections

SUMMARYAcanthamoebaspp. are free-living protists widely distributed in environment, able to cause keratitis, encephalitis and skin lesions in humans and animals.Acanthamoebaspp. exist in two forms: an infective trophozoite and a dormant cyst. Several factors contribute to the pathogenesis ofAcanthamoebaspp. The parasite adhesion to the host cell is the primary step for infection and is mediated by a mannose binding-protein, expressed in the surface and considered the main pathogenicity factor inAcanthamoebaspp. So far, there was no evidence of another surface protein ofAcanthamoebaspp. relevant for host invasion or infection by these organisms. The aims of this study were to identify and characterize anAcanthamoeba castellaniisurface protein and to evaluate its diagnostic potential.In silicopredictions of surface proteins allowed to identify theA. castellaniicalreticulin as a possible surface antigen. The coding sequence of a predicted extracellular domain ofA. castellaniicalreticulin was cloned byin vivohomologous recombination and the recombinant polypeptide (AcCRT29–130) was produced. Its immunodiagnostic potential was assessed in a recombinant antigen-based ELISA with sera from experimentally infected rats that developed keratitis and encephalitis, and sera from patients with encephalitis. The AcCRT29–130was significantly more recognized by sera from encephalitis infected rats in comparison with the non-infected controls. Human sera from encephalitis patients, however presented no significant response. These results showed the AcCRT29–130potential forA. castellaniiinfection immunodiagnosis in animals, with further studies being required for assessment of its use for human infections.

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Comparison of adherence of Candida albicans and Candida parapsilosis to silicone catheters in vitro and in vivo

Clinical Microbiology and Infection ◽

10.1046/j.1469-0691.2003.00724.x ◽

2003 ◽

Vol 9 (7) ◽

pp. 684-690 ◽

Cited By ~ 14

Author(s):

E.M. Kojic and ◽

R.O. Darouiche

Keyword(s):

Candida Albicans ◽

Candida Parapsilosis

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Deletions of Endocytic Components VPS28 and VPS32 Affect Growth at Alkaline pH and Virulence through both RIM101-Dependent and RIM101-Independent Pathways in Candida albicans

Infection and Immunity ◽

10.1128/iai.73.12.7977-7987.2005 ◽

2005 ◽

Vol 73 (12) ◽

pp. 7977-7987 ◽

Cited By ~ 56

Author(s):

Muriel Cornet ◽

Frédérique Bidard ◽

Patrick Schwarz ◽

Grégory Da Costa ◽

Sylvie Blanchin-Roland ◽

...

Keyword(s):

Candida Albicans ◽

Active Form ◽

Surface Proteins ◽

Gene Products ◽

Alkaline Ph ◽

Endosomal Sorting ◽

Genes Encoding ◽

Drastic Effect ◽

Ascomycetous Yeasts

ABSTRACT Ambient pH signaling involves a cascade of conserved Rim or Pal products in ascomycetous yeasts or filamentous fungi, respectively. Recent evidences in the fungi Aspergillus nidulans, Saccharomyces cerevisiae, Yarrowia lipolytica, and Candida albicans suggested that components of endosomal sorting complexes required for transport (ESCRT) involved in endocytic trafficking were needed for signal transduction along the Rim pathway. In this study, we confirm these findings with C. albicans and show that Vps28p (ESCRT-I) and Vps32p/Snf7p (ESCRT-III) are required for the transcriptional regulation of known targets of the Rim pathway, such as the PHR1 and PHR2 genes encoding cell surface proteins, which are expressed at alkaline and acidic pH, respectively. We additionally show that deletion of these two VPS genes, particularly VPS32, has a more drastic effect than a RIM101 deletion on growth at alkaline pH and that this effect is only partially suppressed by expression of a constitutively active form of Rim101p. Finally, in an in vivo mouse model, both vps null mutants were significantly less virulent than a rim101 mutant, suggesting that VPS28 and VPS32 gene products affect virulence both through Rim-dependent and Rim-independent pathways.

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