Cloning and Molecular Characterization ofCnTEF1Which Encodes Translation Elongation Factor 1α inCryptococcus neoformans

Thornewell, Susan J.; Peery, Robert B.; Skatrud, Paul L.

doi:10.1006/fgbi.1997.1002

Cited by 4 publications

(2 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An EF3-like gene cloned from the Chlorella virus shows a similar low identity (36%), but the functional significance of this latter gene has not been established (33). In contrast, the homology of EF1 between the two classes is much higher (84.7% identity) (28) and suggests a greater evolutionary drift of the third translational cofactor within phyla of Fungi. Low identity between CnEF3 and ascomycete fungi may also help in determining the functional significance of amino acids within the protein.…”

Section: Discussionmentioning

confidence: 98%

Evolutionary Divergence of an Elongation Factor 3 from Cryptococcus neoformans

et al. 2001

View full text Add to dashboard Cite

Elongation factor 3 (EF3) is considered a promising drug target for the control of fungal diseases because of its requirement for protein synthesis and survival of fungi and a lack of EF3 in the mammalian host. However, EF3 has been characterized only in ascomycete yeast. In order to understand the role of EF3 in a basidiomycete yeast, we cloned the gene encoding EF3 from Cryptococcus neoformans (CnEF3), an important fungal pathogen in immunocompromised patients, including those infected with human immunodeficiency virus. CnEF3 was found to encode a 1,055-amino-acid protein and has 44% identity with EF3 from Saccharomyces cerevisiae (YEF3). Expressed CnEF3 exhibited ATPase activity that was only modestly stimulated by ribosomes from S. cerevisiae. In contrast, CnEF3 showed tight binding to cryptococcal ribosomes, as shown by an inability to be removed under conditions which successfully remove Saccharomyces EF3 from ribosomes (0.5 M KCl or 2 M LiCl). CnEF3 also poorly complemented a YEF3 defect in a diploid null mutant and two temperature-sensitive mutants which have been shown previously to be complemented well by EF3 from other ascomycetes, such as Candida albicans. These data clearly identify the presence of a functioning EF3 in the basidiomycete yeast C. neoformans, which demonstrates an evolutionary divergence from EF3 of ascomycete yeast.Cryptococcus neoformans is an important fungal pathogen which causes a lethal meningoencephalitis in a significant number of persons with AIDS and afflicts an increasing number of immunocompromised patients on steroids, chemotherapy, or posttransplant immunosuppressives (18). Therapy of cryptococcosis is limited by toxicity of such agents as amphotericin B (1); newer agents such as the azole inhibitors are less toxic, but increasing reports of resistance may limit their eventual usefulness (3,15,17). Echinocandins and pneumocandins are important new antifungal agents which are inhibitors of 1,3-␤-glucan synthetases and show excellent activity against ascomycete pathogens such as Candida albicans and Aspergillus fumigatus, but alterations in this enzyme from basidiomycetes make this important class of agents ineffective against C. neoformans (27). The latter example shows the potential gap in antifungal coverage which may occur when inhibitors are chosen without consideration of possible evolutionary differences in drug targets within various fungal pathogens.Elongation factor 3 (EF3) has been shown to be a required translation cofactor in the ascomycete Saccharomyces cerevisiae (7). The factor is also present in a variety of pathogenic ascomycete fungi, including Candida albicans (8) and the pathogen Pneumocystis carinii (34), which has been shown to be closely related to ascomycete yeasts based on analysis of its rRNA gene as well as genes encoding dihydrofolate reductase, thymidylate synthetase, ␤-tubulin, and ATP (for a review, see reference 31). While an anti-EF3 antibody has been shown to react with basidiomycete yeasts (4), EF3 has not been characterized from this cl...

show abstract

Section: Discussionmentioning

confidence: 98%

Evolutionary Divergence of an Elongation Factor 3 from Cryptococcus neoformans

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Although touchdown PCR has been used successfully to help overcome some of the uncertainties associated with the thermal amplification of microbial nucleic acid targets [19][20][21][22], its use in this study has extended its role further and in so doing brought closer the goal of undertaking molecular diagnostics in a routine setting. Previously its main impact has been seen where multiplexing [23,24] or degenerate primers have been needed [25][26][27] and where the problems of choosing correct annealing temperatures are at their most difficult.…”

Section: Discussionmentioning

confidence: 99%

A touchdown nucleic acid amplification protocol as an alternative to culture backup for immunofluorescence in the routine diagnosis of acute viral respiratory tract infections

et al. 2004

View full text Add to dashboard Cite

Background: Immunofluorescence and virus culture are the main methods used to diagnose acute respiratory virus infections. Diagnosing these infections using nucleic acid amplification presents technical challenges, one of which is facilitating the different optimal annealing temperatures needed for each virus. To overcome this problem we developed a diagnostic molecular strip which combined a generic nested touchdown protocol with in-house primer master-mixes that could recognise 12 common respiratory viruses.

show abstract

One stop mycology

Frazer

1999

Mycological Research

View full text Add to dashboard Cite

Cloning and Molecular Characterization ofCnTEF1Which Encodes Translation Elongation Factor 1α inCryptococcus neoformans

Cited by 4 publications

References 29 publications

Evolutionary Divergence of an Elongation Factor 3 from Cryptococcus neoformans

Evolutionary Divergence of an Elongation Factor 3 from Cryptococcus neoformans

A touchdown nucleic acid amplification protocol as an alternative to culture backup for immunofluorescence in the routine diagnosis of acute viral respiratory tract infections

One stop mycology

Contact Info

Product

Resources

About