Hmt1p is the predominant arginine methyltransferase in Saccharomyces cerevisiae. Its substrate proteins are involved in transcription, transcriptional regulation, nucleocytoplasmic transport and RNA splicing. Functionally, Hmt1p-catalysed methylation can also modulate protein-protein interactions. Despite Hmt1p being well-characterised, the effects of its knockout on the proteome and transcriptome have not been reported. SILAC-based analyses of the hmt1 proteome, in mid-log exponential growth, revealed a decreased abundance of phosphate-associated proteins including Pho84p (phosphate transporter), Pho8p (vacuolar alkaline phosphatase), Pho3p (acid phosphatase) along with Vtc1p, Vtc3p and Vtc4p (subunits of the vacuolar transporter chaperone complex). RNA-Seq and microarray analysis revealed a downregulation of phosphate-responsive genes in hmt1, including PHO5, PHO11 and PHO12 (acid phosphatases), PHO84 and PHO89 (phosphate transporters) and VTC3 (vacuolar transporter chaperone). Consistent with these observations, we observed a dysregulation of phosphate homeostasis in hmt1, with a general decrease in extracellular phosphatase production and a decrease in total Pi in phosphate replete medium. We show that the transcription factor Pho4p, responsible for activation of the PHO pathway, can be methylated by Hmt1p at Arg-241 and is the likely cause of phosphate dysregulation in hmt1. However, the methylation of Pho4p does not affect its nucleocytoplasmic localisation. We propose that the methylation of Pho4p may affect either its capacity to multimerise, its capacity to interact with Pho2p or target DNA, or may affect Pho4p phosphorylation at Ser-242 and/or Ser 243. Our study highlights a previously unknown function of Hmt1p in the regulation of phosphate homeostasis and suggests a means by which sensing of AdoMet may affect intracellular phosphate concentration.
Knockout of the Hmt1p Arginine Methyltransferase in <i>Saccharomyces cerevisiae</i> Leads to the Dysregulation of Phosphate-associated Genes and Processes.
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View SamplesIntegrated DNA and expression array analysis in primary human breast tumors identified chromosome 8q22 copy number gain and a suite of over-expressed genes in this region highly relevant to subsequent recurrence.
Amplification of LAPTM4B and YWHAZ contributes to chemotherapy resistance and recurrence of breast cancer.
Age, Specimen part, Subject
View SamplesBackground: We have previously shown that the Gene expression Grade Index (GGI) was able to identify two subtypes of estrogen receptor (ER)-positive tumors that were associated with statistically distinct clinical outcomes in both untreated and tamoxifen-treated patients. Here, we aim to investigate the ability of the GGI to predict relapses in postmenopausal women who were treated with tamoxifen (T) or letrozole (L) within the BIG 1-98 trial.
The Gene expression Grade Index: a potential predictor of relapse for endocrine-treated breast cancer patients in the BIG 1-98 trial.
Age, Specimen part, Disease stage, Treatment
View SamplesWhether the human tumor virus, Epstein-Barr virus (EBV) promotes breast cancers remains controversial and a potential mechanism has remained elusive. Here we show EBV can infect primary mammary epithelial cells (MECs) that express the attachment receptor, CD21. EBV infection leads to the expansion of early MEC progenitor cells with a stem cell phenotype and enforces a differentiation block. When MECs were implanted as xenografts, EBV infection cooperated with activated Ras and accelerated the formation of breast cancer. Infection in EBV-related tumors was of a latency type II pattern, including expression of latent membrane proteins 1 (LMP1) and 2 (LMP2), similar to nasopharyngeal carcinoma (NPC). A human gene expression signature for EBVness was generated based on the RNA expression profile of the EBV infected primary mammary epithelial cells, tumors. This was signature associated with high grade (40 vs 13.5%) estrogen-receptor-negative status (31.8 vs. 10.5%, p53 mutation (37.5 vs 14.5%) and poor survival. In 11/33 (33%) of tumors positive for EBVness EBV-DNA was found in tumor cells by fluorescent in situ hybridization for the viral LMP1 and BXLF2 genes, while only 4/36 (11%) of EBVness-negative tumors tested positive for EBV DNA. An analysis of the TCGA breast cancer data revealed a correlation of EBVness with presence of the APOBEC mutational signatures consistent with past viral infection. We conclude that a contribution of EBV to breast cancer etiology via a hit-and-run mechanism is plausible, in which EBV infection predisposes mammary epithelial cells to malignant transformation, but is not required for the maintenance of the malignant phenotype.
Epstein-Barr Virus Infection of Mammary Epithelial Cells Promotes Malignant Transformation.
Specimen part, Cell line
View SamplesUsing mouse lung resident conventional CD11b+ dendritic cells (CD11b+ cDCs) in the context of house-dust mite (HDM)-driven allergic airway sensitization as a model, we aimed here to identify transcriptional events regulating the pro-Th2 activity of cDCs.
Interferon response factor-3 promotes the pro-Th2 activity of mouse lung CD11b<sup>+</sup> conventional dendritic cells in response to house dust mite allergens.
Sex, Specimen part
View SamplesUsing a dataset of 54 pregnant and 113 age/stage-matched non-pregnant breast cancer patients with complete clinical and survival data; we evaluated the pattern of hot spot somatic mutations and performed transcriptomic profiling using Sequenom and Affymetrix, respectively. Breast cancer molecular subtypes were defined using PAM50 and 3-Gene classifiers. We performed Gene set enrichment analysis (GSEA) to evaluate pathways associated with diagnosis during pregnancy. We investigated the differential expression of cancer-related genes and published gene sets according to pregnancy. We finally investigated genes associated with disease-free survival.
Biology of breast cancer during pregnancy using genomic profiling.
Age, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Type I and type III interferons drive redundant amplification loops to induce a transcriptional signature in influenza-infected airway epithelia.
Specimen part
View SamplesWe used microarrays to detail the global programme of gene expression in response to Influenza A (PR8) infection
Type I and type III interferons drive redundant amplification loops to induce a transcriptional signature in influenza-infected airway epithelia.
Specimen part
View SamplesWe used microarrays to detail the global programme of gene expression in response to Influenza A (PR8) infection
Type I and type III interferons drive redundant amplification loops to induce a transcriptional signature in influenza-infected airway epithelia.
Specimen part
View SamplesWe used microarrays to detail the global programme of gene expression in response to Influenza A (PR8) infection
Type I and type III interferons drive redundant amplification loops to induce a transcriptional signature in influenza-infected airway epithelia.
Specimen part
View Samples