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Series GSE69361 Query DataSets for GSE69361
Status Public on May 30, 2015
Title Effect of pH on gene expression in two glucosyl ceramide (GlcCer) mutant strains of Cryptococcus neoformans H99
Organism Cryptococcus neoformans var. grubii H99
Experiment type Expression profiling by array
Summary Background The sphingolipid Glucosylceramide (GlcCer) and factors involved in the fungal GlcCer pathways were shown earlier to be an integral part of fungal virulence, especially in fungal replication at 37°C, in neutral/alkaline pH and 5% CO2 environments (e.g. alveolar spaces). Two mutants (null mutants’ delta-gcs1 and delta-smt1 lacking glucosylceramide synthase 1 gene and C9 sphingolipid methyltransferase 1 gene respectively) of this pathway were attenuated in virulence and have a growth defect at the above-mentioned conditions. These mutants with either no or structurally modified GlcCer located on the cell-membrane have reduced membrane rigidity, which may have altered not only the physical location of membrane proteins but also their expression, as the pathogen’s mode of adaptation to changing need. Importantly, pathogens are known to adapt themselves to the changing host environments by altering their patterns of gene expression. Results By transcriptional analysis of gene expression, we identified six genes whose expression was changed from their wild-type counterpart grown in the same conditions, i.e they became either down regulated or up regulated in these two mutants. The microarray data was validated by real-time PCR, which confirmed their fold change in gene expression. The 6 genes we identified, viz siderochrome-iron transporter (CNAG_02083), monosaccharide transporter (CNAG_05340), glucose transporter (CNAG_03772), membrane protein (CNAG_03912), membrane transport protein (CNAG_00539), and sugar transporter (CNAG_06963), all of which are membrane-localized and have significantly altered gene expression levels. Therefore, we speculate that these genes function either independently or in tandem with a structurally modified cell wall/plasma membrane resulting from the modifications of the GlcCer pathway and thus possibly disrupt trans membrane signaling complex, which in turn contributes to Cryptococcal osmotic, pH, ion homeostasis and its pathobiology. Conclusion Gene expression microarrays identified 6 genes by gene set enrichment analysis and validated by qRT-PCR, which are involved in the trans membrane signaling network in Cryptococcus neoformans, controlling the rigidity of the membrane in neutral-alkaline pH and therefore the pathobiology of the fungus in these conditions.
 
Overall design WT vs ∆smt1 at pH 4, WT vs ∆smt1 at pH 7.2±0.2, WT vs ∆gcs1 at pH 4, WT vs ∆gcs1 at pH 7.2±0.2
 
Contributor(s) Singh A, Rella A, Schwacke J, Vacchi-Suzzi C, Luberto C, Del Poeta M
Citation(s) 26572681
Submission date May 29, 2015
Last update date Nov 23, 2015
Contact name Maurizio Del Poeta
E-mail(s) maurizio.delpoeta@stonybrook.edu
Organization name Stony Brook University
Department Molecular Genetics and Microbiology
Street address 150 Life Science Building
City Stony Brook
State/province NY
ZIP/Postal code 11794
Country USA
 
Platforms (1)
GPL13419 Agilent-019465 The Genome Sequencing Center (GSC) at Washington University Cryptococcus neoformans 14K array
Samples (15)
GSM1698578 Cn_WT vs ∆smt1_pH 7.2_replicate 1
GSM1698579 Cn_WT vs ∆gcs1_pH 7.2_replicate 1
GSM1698580 Cn_WT vs ∆smt1_pH 4.0_replicate 1
Relations
BioProject PRJNA285298

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE69361_RAW.tar 59.8 Mb (http)(custom) TAR (of TXT)
GSE69361_processed_data.txt.gz 573.2 Kb (ftp)(http) TXT
Processed data are available on Series record

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