scholarly journals A Trypanosoma cruzi zinc finger protein that is implicated in the control of epimastigote-specific gene expression and metacyclogenesis

Parasitology ◽  
2020 ◽  
pp. 1-15
Author(s):  
Thais S. Tavares ◽  
Fernanda L. B. Mügge ◽  
Viviane Grazielle-Silva ◽  
Bruna M. Valente ◽  
Wanessa M. Goes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Zinc Finger ◽  
Rna Binding ◽  
Environmental Changes ◽  
Negative Regulator ◽  
Specific Gene ◽  
Genes Encoding ◽  
Transcriptome Analyses

Abstract Trypanosoma cruzi has three biochemically and morphologically distinct developmental stages that are programmed to rapidly respond to environmental changes the parasite faces during its life cycle. Unlike other eukaryotes, Trypanosomatid genomes contain protein coding genes that are transcribed into polycistronic pre-mRNAs and have their expression controlled by post-transcriptional mechanisms. Transcriptome analyses comparing three stages of the T. cruzi life cycle revealed changes in gene expression that reflect the parasite adaptation to distinct environments. Several genes encoding RNA binding proteins (RBPs), known to act as key post-transcriptional regulatory factors, were also differentially expressed. We characterized one T. cruzi RBP, named TcZH3H12, which contains a zinc finger domain and is up-regulated in epimastigotes compared to trypomastigotes and amastigotes. TcZC3H12 knockout (KO) epimastigotes showed decreased growth rates and increased capacity to differentiate into metacyclic trypomastigotes. Transcriptome analyses comparing wild type and TcZC3H12 KOs revealed a TcZC3H12-dependent expression of epimastigote-specific genes such as genes encoding amino acid transporters and proteins associated with differentiation (PADs). RNA immunoprecipitation assays showed that transcripts from the PAD family interact with TcZC3H12. Taken together, these findings suggest that TcZC3H12 positively regulates the expression of genes involved in epimastigote proliferation and also acts as a negative regulator of metacyclogenesis.

scholarly journals A Trypanosoma cruzi Zinc Finger protein that controls expression of epimastigote specific genes and affects metacyclogenesis

2020 ◽  
Author(s):  
Thais Silva Tavares ◽  
Fernanda Lins Brandão Mügge ◽  
Viviane Grazielle-Silva ◽  
Bruna Mattioly Valente ◽  
Wanessa Moreira Goes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Trypanosoma Cruzi ◽  
Zinc Finger ◽  
Rna Binding ◽  
Environmental Changes ◽  
Zinc Finger Protein ◽  
Negative Regulator ◽  
Transcriptional Level ◽  
Control Of Gene Expression ◽  
Genes Encoding

SummaryTrypanosoma cruzi has three biochemically and morphologically distinct developmental stages that are programed to rapidly respond to environmental changes the parasite faces during its life cycle. Unlike other eukaryotes, Trypanosomatid genomes contain protein coding genes that are transcribed into polycistronic pre-mRNAs and control of gene expression relies on mechanisms acting at the post-transcriptional level. Transcriptome analyses comparing epimastigote, trypomastigote and intracellular amastigote stages revealed changes in gene expression that reflect the parasite adaptation to distinct environments. Several genes encoding RNA binding proteins (RBP), known to act as key post-transcriptional regulatory factors, were also differentially expressed. We characterized one T. cruzi RBP (TcZH3H12) that contains a zinc finger domain, and whose transcripts are upregulated in epimastigotes compared to trypomastigotes and amastigotes. TcZC3H12 knockout epimastigotes showed decreased growth rates and increased capacity to differentiate into metacyclic trypomastigotes. Comparative transcriptome analysis revealed a TcZC3H12-dependent expression of epimastigote specific genes encoding amino acid transporters and proteins associated with differentiation (PAD), among others. RNA immunoprecipitation assays showed that transcripts from the PAD family interact with TcZC3H12. Taken together, these findings suggest that TcZC3H12 positively regulates the expression of genes involved in epimastigote proliferation and also acts as a negative regulator of metacyclogenesis.

scholarly journals Conserved RNA Binding Activity of Phosphatidyl Inositol 5-Phosphate 4-Kinase (PIP4K2A)

2021 ◽  
Vol 8 ◽  
Author(s):  
Jatin Behari ◽  
Pranita Borkar ◽  
Arya Vindu ◽  
Vishal Dandewad ◽  
Sindhuri Upadrasta ◽  
...  
Keyword(s):  
Gene Expression ◽  
Life Cycle ◽  
Posttranscriptional Regulation ◽  
Rna Binding ◽  
Phosphatidyl Inositol ◽  
Binding Activity ◽  
Malarial Parasite ◽  
Complex Life Cycle ◽  
Specific Gene ◽  
Relative Paucity

Plasmodium falciparum is a causative agent for malaria and has a complex life cycle in human and mosquito hosts. During its life cycle, the malarial parasite Plasmodium goes through different asexual and sexual stages, in humans and mosquitoes. Expression of stage-specific proteins is important for successful completion of its life cycle and requires tight gene regulation. In the case of Plasmodium, due to relative paucity of the transcription factors, it is postulated that posttranscriptional regulation plays an important role in stage-specific gene expression. Translation repression of specific set of mRNA has been reported in gametocyte stages of the parasite. A conserved element present in the 3′UTR of some of these transcripts was identified. Phosphatidylinositol 5-phosphate 4-kinase (PIP4K2A) was identified as the protein that associates with these RNA. We now show that the RNA binding activity of PIP4K2A is independent of its kinase activity. We also observe that PIP4K2A is imported into the parasite from the host on Plasmodium berghei and Toxoplasma gondii. The RNA binding activity of PIP4K2A seems to be conserved across species from Drosophila and C. elegans to humans, suggesting that the RNA binding activity of PIP4K may be important, and there may be host transcripts that may be regulated by PIP4K2A. These results identify a novel RNA binding role for PIP4K2A that may not only play a role in Plasmodium propagation but may also function in regulating gene expression in multicellular organisms.

scholarly journals ARID2 Chromatin Remodeler in Hepatocellular Carcinoma

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2152
Author(s):  
Robin Loesch ◽  
Linda Chenane ◽  
Sabine Colnot
Keyword(s):  
Gene Expression ◽  
Hepatocellular Carcinoma ◽  
Associated Factors ◽  
Regulation Of Gene Expression ◽  
Specific Gene ◽  
Chromatin Remodeler ◽  
Chromatin Remodelers ◽  
Genes Encoding ◽  
Gene Alterations

Chromatin remodelers are found highly mutated in cancer including hepatocellular carcinoma. These mutations frequently occur in ARID (AT-rich Interactive Domain) genes, encoding subunits of the ATP-dependent SWI/SNF remodelers. The increasingly prevalent complexity that surrounds the functions and specificities of the highly modular BAF (BG1/BRM-associated factors) and PBAF (polybromo-associated BAF) complexes, including ARID1A/B or ARID2, is baffling. The involvement of the SWI/SNF complexes in diverse tissues and processes, and especially in the regulation of gene expression, multiplies the specific outcomes of specific gene alterations. A better understanding of the molecular consequences of specific mutations impairing chromatin remodelers is needed. In this review, we summarize what we know about the tumor-modulating properties of ARID2 in hepatocellular carcinoma.

scholarly journals NDT80 and the Meiotic Recombination Checkpoint Regulate Expression of Middle Sporulation-Specific Genes in Saccharomyces cerevisiae

1998 ◽  
Vol 18 (10) ◽  
pp. 5750-5761 ◽  
Author(s):  
Shelley R. Hepworth ◽  
Helena Friesen ◽  
Jacqueline Segall
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Active Form ◽  
Specific Gene ◽  
Subsequent Generation ◽  
Genes Encoding ◽  
Recombination Checkpoint ◽  
Sporulation Genes ◽  
Meiosis I

ABSTRACT Distinct classes of sporulation-specific genes are sequentially expressed during the process of spore formation in Saccharomyces cerevisiae. The transition from expression of early meiotic genes to expression of middle sporulation-specific genes occurs at about the time that cells exit from pachytene and form the meiosis I spindle. To identify genes encoding potential regulators of middle sporulation-specific gene expression, we screened for mutants that expressed early meiotic genes but failed to express middle sporulation-specific genes. We identified mutant alleles ofRPD3, SIN3, and NDT80 in this screen. Rpd3p, a histone deacetylase, and Sin3p are global modulators of gene expression. Ndt80p promotes entry into the meiotic divisions. We found that entry into the meiotic divisions was not required for activation of middle sporulation genes; these genes were efficiently expressed in a clb1 clb3 clb4 strain, which fails to enter the meiotic divisions due to reduced Clb-dependent activation of Cdc28p kinase. In contrast, middle sporulation genes were not expressed in a dmc1 strain, which fails to enter the meiotic divisions because a defect in meiotic recombination leads to aRAD17-dependent checkpoint arrest. Expression of middle sporulation genes, as well as entry into the meiotic divisions, was restored to a dmc1 strain by mutation of RAD17. Our studies also revealed that NDT80 was a temporally distinct, pre-middle sporulation gene and that its expression was reduced, but not abolished, on mutation of DMC1,RPD3, SIN3, or NDT80 itself. In summary, our data indicate that Ndt80p is required for expression of middle sporulation genes and that the activity of Ndt80p is controlled by the meiotic recombination checkpoint. Thus, middle genes are expressed only on completion of meiotic recombination and subsequent generation of an active form of Ndt80p.

scholarly journals Phosphatidylinositol 3-Kinase Is a Negative Regulator of Cellular Differentiation

1997 ◽  
Vol 137 (5) ◽  
pp. 1127-1136 ◽  
Author(s):  
Andrzej Ptasznik ◽  
Gillian M. Beattie ◽  
Martin I. Mally ◽  
Vincenzo Cirulli ◽  
Ana Lopez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cellular Differentiation ◽  
Precursor Cells ◽  
Negative Regulator ◽  
Specific Gene ◽  
Phosphatidylinositol 3 Kinase ◽  
Specific Gene Expression ◽  
Endocrine Differentiation ◽  
Pi3k Activity ◽  
Phosphatidylinositol 3

Phosphatidylinositol 3-kinase (PI3K) has been shown to be an important mediator of intracellular signal transduction in mammalian cells. We show here, for the first time, that the blockade of PI3K activity in human fetal undifferentiated cells induced morphological and functional endocrine differentiation. This was associated with an increase in mRNA levels of insulin, glucagon, and somatostatin, as well as an increase in the insulin protein content and secretion in response to secretagogues. Blockade of PI3K also increased the proportion of pluripotent precursor cells coexpressing multiple hormones and the total number of terminally differentiated cells originating from these precursor cells. We examined whether any of the recently described modulators of endocrine differentiation could participate in regulating PI3K activity in fetal islet cells. The activity of PI3K was inversely correlated with the hepatocyte growth factor/scatter factor–induced downregulation or nicotinamideinduced upregulation of islet-specific gene expression, giving support to the role of PI3K, as a negative regulator of endocrine differentiation. In conclusion, our results provide a mechanism for the regulation of hormone-specific gene expression during human fetal neogenesis. They also suggest a novel function for PI3K, as a negative regulator of cellular differentiation.

Deletion and overexpression of the Aspergillus nidulans GATA factor AreB reveals unexpected pleiotropy

Microbiology ◽  
2009 ◽  
Vol 155 (12) ◽  
pp. 3868-3880 ◽  
Author(s):  
Koon Ho Wong ◽  
Michael J. Hynes ◽  
Richard B. Todd ◽  
Meryl A. Davis
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Aspergillus Nidulans ◽  
Zinc Finger ◽  
Leucine Zipper ◽  
Binding Domain ◽  
Negative Regulator ◽  
Dna Binding Domain ◽  
Gata Factor ◽  
Nitrogen Acquisition

The Aspergillus nidulans transcription factor AreA is a key regulator of nitrogen metabolic gene expression. AreA contains a C-terminal GATA zinc finger DNA-binding domain and activates expression of genes necessary for nitrogen acquisition. Previous studies identified AreB as a potential negative regulator of nitrogen catabolism showing similarity with Penicillium chrysogenum NreB and Neurospora crassa ASD4. The areB gene encodes multiple products containing an N-terminal GATA zinc finger and a leucine zipper motif. We deleted the areB gene and now show that AreB negatively regulates AreA-dependent nitrogen catabolic gene expression under nitrogen-limiting or nitrogen-starvation conditions. AreB also acts pleiotropically, with functions in growth, conidial germination and asexual development, though not in sexual development. AreB overexpression results in severe growth inhibition, aberrant cell morphology and reduced AreA-dependent gene expression. Deletion of either the DNA-binding domain or the leucine zipper domain results in loss of both nitrogen and developmental phenotypes.

scholarly journals Gene Expression Profiles for Recurrence of Lymph Node-positive Primary Breast Cancer in Women Over 40 Years of Age

2021 ◽  
Author(s):  
Sean Si Qian Ma ◽  
Luyi Ye ◽  
Fan Zhang ◽  
Tiansheng Xu ◽  
Zai-Si Ji ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Lymph Node ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Olfactory Receptors ◽  
Specific Gene ◽  
Node Metastasis ◽  
Genes Encoding ◽  
Ffpe Samples

Abstract Background: Specific gene expression profiles correlate with recurrence of breast cancer in lymph node-negative patients. In contrast, insufficient knowledge is available regarding tumor-specific gene expression in patients with lymph node metastasis before surgery. Furthermore, such patients experience cumulative incidences of relapse greater than 50%. Methods: Sections of formalin-fixed paraffin embedded (FFPE) were prepared from breast tumors of 37 patients who were followed for at least 5 years. FFPE samples of patients with recurrent ductal breast cancer (n = 25) and 12 FFPE samples of such patients without recurrence were subjected to microarray analysis to identify gene expression profiles specifically associated with positive lymph nodes confirmed during surgery that were accompanied by lymphocytic invasion. Immunohistochemistry was employed to determine the estrogen receptor (ER) status of cancer tissues. All patients were administered tamoxifen after surgery, and this treatment continued for more than 5 years, or until cancer recurred. This strategy eliminated interactions between different therapeutics as potential confounding factors that influenced patients' outcomes.Results: Sixteen genes were expressed at significantly higher levels in patients with ER-positive (+) breast cancer with recurrence compared with those without recurrence. Gene Set Enrichment Analysis of The Kyoto Encyclopedia of Genes and Genomes (KEGG) identified 73 genes encoding olfactory receptors included in the “Olfactory transduction” pathway that were enriched in the ER+ recurrence group (FDR P < 0.05). The KEGG “Histidine metabolism” and “Retinol metabolism” pathways were enriched in patients with ER-negative (–) breast cancer with recurrence (FDR P < 0.05). Conclusions: The present study is the first, to our knowledge, to identify 16 genes encoding proteins with diverse functions as well as 73 genes encoding olfactory receptors. These genes may serve as presurgical biomarkers for the recurrence of ER+ breast cancers with lymph node metastasis before surgery. These findings identify potential therapeutic targets for preventing cancer relapse, particularly after lymph nodes metastasis.

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