E-GEOD-17338 - The role of the Ras- and cAMP-signaling pathways in stress response and sterol biosynthesis in Cryptococcus neoformans
Submitted on 26 July 2009, released on 22 May 2010, last updated on 1 May 2014
Cryptococcus neoformans var. grubii H99
The cAMP-pathway plays a central role in regulation of growth, differentiation, and virulence of human pathogenic fungi, including Cryptococcus neoformans. Three major upstream signaling regulators of the adenylyl cyclase (Cac1), Ras, Aca1 (Adenylyl cyclase-associated protein 1) and G-alpha subunit protein (Gpa1), have been identified to control the cAMP-pathway in C. neoformans, but their functional relationship remains elusive. Here we performed genome-wide transcriptome analysis with C. neoformans ras1, gpa1, cac1, aca1, and pka1 pka2 mutants by DNA microarray. The aca1, gpa1, cac1, and pka1 pka2 mutants displayed similar transcriptome patterns to each other whereas the ras1 mutant exhibited distinctive transcriptome patterns compared to WT and the cAMP mutants. Interestingly, a number of environmental stress response genes are differentially modulated in the ras1 and cAMP mutants. In fact, the Ras1-signaling pathway was found to be involved in osmotic and genotoxic stress response, and maintenance of cell wall integrity via the Cdc24-dependent signaling pathway. Through this microarray analysis, we have identified a number of cAMP-dependent genes, including GRE2, HSP12, ENA1, TCO2, PKP2, CAT1, in C. neoformans. Notably, a majority of ergosterol biosynthesis genes were found to be upregulated in the cAMP mutants. Interestingly, the gpa1, cac1, and pka1 mutants, but not the aca1 and pka2 mutants were hypersensitive to amphotericin B, but resistant to fluconazole. In conclusion, we demonstrated in this study that the Ras1- and cAMP-signaling pathways are involved in stress response and sterol biosynthesis of C. neoformans. There are more than 95% of genome homology between JEC21 and H99. Therefore 100 slides of JEC21 (cryptococcus neoformans var. neoformans serotype D) 70-mer oligo are used in this analysis, 3 biological replicate experiments are performed, total RNAs are extracted with 6 strains from H99 (H99 Wild type strain (Cryptococcus neoformans var. grubii serotype A), ras1Δ, aca1Δ, gpa1Δ, cac1Δ, pka1Δpka2Δ), We use the mixed all of total RNAs from this experiment as a control RNA. We use Cy5 as Sample dye and Cy3 as a control dye. several sample are dye swaped.
transcription profiling by array
Yong-Sun Bahn <email@example.com>, Dong-Hoon Yang, Gyu-Bum Kim, Jeseph Heitman, Kwang-Woo Jung, Shinae Maeng, Young-Joon Ko
Comparative transcriptome analysis reveals novel roles of the Ras and cyclic AMP signaling pathways in environmental stress response and antifungal drug sensitivity in Cryptococcus neoformans. Maeng S, Ko YJ, Kim GB, Jung KW, Floyd A, Heitman J, Bahn YS.