Original Article

The Effect of EFG1 Gene Silencing on Down-Regulation of SAP5 Gene, by Use of RNAi Technology

Abstract

Efg1 transcription factor is believed to be the main regulator of hyphal formation under many different conditions. In addition, it is responsible for positive regulation of the expression of several hyphal-specific genes. SAP5, which encodes secreted aspartic proteinase, is one of the mentioned genes and is crucial for pathogenicity properties. In the present work we have established the experimental conditions for the use of siRNA in the diploid yeast Candida albicans in order to knock-down the EFG1 gene expression as well as the Efg1-dependent gene, SAP5. The 19-nucleotide siRNA was designed according to cDNA sequence of EFG1 gene in C. albicans and modified-PEG/LiAc method was applied for yeast transfection. To quantify the level of both EFG1 and SAP5 gene expression, the cognate mRNAs were measured in C. albicans by quantitative real-time RT-PCR and data was consequently analyzed by use of REST® software. Images taken by fluorescent microscopy method indicated the effectiveness of transfection. According to REST® software data analysis, expression of EFG1 gene decreased about 2.5-fold using 500 nM of siRNA. A 7-fold decrease in EFG1 gene expression was observed when applying 1 µM of siRNA (P<0.05). Consequently, the expression of SAP5 was significantly down-regulated both in yeast treated with 500 and 1000 nM of siRNA (P<0.05). In conclusion, post-transcriptional gene silencing (PTGS) is likely to be considered as a promising approach to discover new gene targets so as to design fungal-specific antifungal agents, and it is strongly possible that we are taking the right way to battle with C. albicans-associated infections.

Sudbery P, Gow N, Berman J. The distinct morphogenic states of Candida albicans. Trends Microbiol 2004;12(7):317-24.

Kumamoto CA, Vinces MD. Contributions of hyphae and hypha-co-regulated genes to Candida albicans virulence. Cell Microbiol 2005;7(11):1546-54.

Carlisle PL, Kadosh D. Candida albicans Ume6, a filament-specific transcriptional regulator, directs hyphal growth via a pathway involving Hgc1 cyclin-related protein. Eukaryot Cell 2010;9(9):1320-8.

Banerjee M, Thompson DS, Lazzell A, et al. UME6, a novel filament-specific regulator of Candida albicans hyphal extension and virulence. Mol Biol Cell2008;19(4):1354-65.

Sudbery PE. Growth of Candida albicans hyphae. Nat Rev Microbiol 2011;9(10):737-48.

Stoldt VR, Sonneborn A, Leuker CE, et al. Efg1p, an essential regulator of morphogenesis of the human

pathogen Candida albicans, is a member of a conserved class of bHLH proteins regulating morphogenetic processes in fungi. EMBO J 1997;16(8):1982-91.

Leng P, Lee PR, Wu H, et al. Efg1, a morphogenetic regulator in Candida albicans, is a sequence-specific DNA binding protein. J Bacteriol 2001;183(13):4090-3.

Lo HJ, Kohler JR, DiDomenico B, et al. Nonfilamentous C. albicans mutants are avirulent. Cell 1997;90(5):939-49.

Braun BR, Johnson AD. TUP1, CPH1 and EFG1 make independent contributions to filamentation in Candida albicans. Genetics 2000;155(1):57-67.

Naglik J, Albrecht A, Bader, et al. Candida albicansproteinases and host/pathogen interactions. Cell Microbiol 2004;6(10):915-26.

Lermann U, Morschhauser J. Secreted aspartic proteases are not required for invasion of reconstituted human epithelia by Candida albicans. Microbiology 2008;154(Pt11):3281-95.

Cottrell TR, Doering TL. Silence of the strands: RNA interference in eukaryotic pathogens. Trends Microbiol 2003;11(1):37-43.

Marques JT, Williams BRG. Activation of the mammalian immune system by siRNAs. Nat Biotechnol 2005;23(11):1399-405.

Janbon G, Maeng S, Yang DH, et al. Characterizing the role of RNA silencing components in Cryptococcus neoformans. Fungal Genet Biol 2010;47(12):1070-80.

Khatri M, Rajam MV. Targeting polyamines of Aspergillus nidulans by siRNA specific to fungal ornithine decarboxylase gene. Med Mycol 2007;45(3):211-20.

Rappleye CA, Engle JT, Goldman WE. RNA interference in Histoplasma capsulatum demonstrates a role for alpha- (1,3)-glucan in virulence. Mol Microbiol 2004;53(1):153-65.

Rao DD, Vorhies JS, Senzer N, et al. siRNA vs. shRNA: similarities and differences. Adv Drug Deliv Rev 2009;61(9):746-59.

Jinek M, Doudna JA. A three-dimensional view of the molecular machinery of RNA interference. Nature 2009;457(7228):405-12.

Calderone RA, Fonzi WA. Virulence factors of Candida albicans. Trends Microbiol 2001;9(7):327-35.

Zakikhany K, Thewes S, Wilson D, et al. From Attachment to Invasion: Infection Associated Genes of Candida albicans. Jpn J Med Mycol 2008;49(4):245-51.

Villar CC, Kashleva H, Nobile CJ, et al. Mucosal tissue invasion by Candida albicans is associated with E-cadherin degradation, mediated by transcription factor Rim101p and protease Sap5p. Infect Immun 2007;75(5):2126-35.

Korting HC, Hube B, Oberbauer S, et al. Reduced expression of the hyphal-independent Candida albicans proteinase genes SAP1 and SAP3 in the efg1 mutant is associated with attenuated virulence during infection of oral epithelium. J Med Microbiol 2003;52(Pt 8):623-32.

Staab JF, White TCMarr KA. Hairpin dsRNA does not trigger RNA interference in Candida albicans cells. Yeast 2011;28(1):1-8.

Nakayashiki H. RNA silencing in fungi: mechanisms and applications. FEBS Lett 2005;579(26):5950-7.

Files
IssueVol 52, No 1 (2014) QRcode
SectionOriginal Article(s)
Keywords
Candida albicans EFG1 SAP5 siRNA

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
1.
Moazeni M, Khoramizadeh MR, Teimoori-Toolabi L, Noorbakhsh F, Rezaie S. The Effect of EFG1 Gene Silencing on Down-Regulation of SAP5 Gene, by Use of RNAi Technology. Acta Med Iran. 1;52(1):9-14.