Search results for "Gene Expression Regulation"
showing 10 items of 2328 documents
Characterization of a putative extracellular matrix protein from the beetle Tenebrio molitor: hormonal regulation during metamorphosis.
2004
0949-944X (Print) Journal Article Research Support, Non-U.S. Gov't; We used differential display to isolate epidermis cDNAs corresponding to juvenile-hormone analog-regulated mRNA from the beetle Tenebrio molitor. One of them encodes a putative extracellular matrix (ECM) protein, named Tenebrin. Indeed, the deduced protein sequence contains ECM typical features like the presence of a signal peptide, internal repeats, a RGD tripeptide sequence motif known to bind integrins and von Willebrand factor type c domains involved in protein-protein interactions. Northern blot analysis reveals a single transcript of about 11 kb with an expression pattern correlated to 20-hydroxyecdysone fluctuations …
Characterization of two new cuticular genes specifically expressed during the post-ecdysial molting period in Tenebrio molitor
1998
Abstract In a previous study, we have isolated a cDNA, TM-ACP17 , coding for a post-ecdysial adult protein of Tenebrio molitor . After screening of a genomic library with TM-ACP17 , we report isolation and sequencing of TM-ACP17 gene and a new gene, TM-LPCP29 , coding for a larval–pupal protein. These two genes exhibit a common sequence of 15 nucleotides and a characteristic of most cuticular protein genes so far described: an intron interrupting the signal peptide. The deduced aa sequence of TM-LPCP29 exhibits a high percentage of Ala (26.5%) and Val (17.5%) and is highly hydrophobic. In the N-terminal part, the motif VAAPV is repeated ten times. Numerous histidine residues are present in …
Candida albicans TDH3 gene promotes secretion of internal invertase when expressed in Saccharomyces cerevisiae as a glyceraldehyde-3-phosphate dehydr…
2003
We have checked the ability of the Candida albicans GAPDH polypeptide, which lacks a conventional N-terminal signal peptide, to reach the cell wall in Saccharomyces cerevisiae by using an intracellular form of the yeast invertase as a reporter protein. A hybrid TDH3-SUC2 gene containing the C. albicans TDH3 promoter sequences and a coding region encoding a fusion protein formed by the C. albicans GAPDH polypeptide, fused at its C-terminus with the yeast internal invertase, was constructed in a centromer derivative plasmid and transformed into a Suc(-) S. cerevisiae strain. Transformants displayed invertase activity measured in intact whole cells, and were able to grow on sucrose as the sole…
Understanding disease mechanisms with models of signaling pathway activities
2014
Background Understanding the aspects of the cell functionality that account for disease or drug action mechanisms is one of the main challenges in the analysis of genomic data and is on the basis of the future implementation of precision medicine. Results Here we propose a simple probabilistic model in which signaling pathways are separated into elementary sub-pathways or signal transmission circuits (which ultimately trigger cell functions) and then transforms gene expression measurements into probabilities of activation of such signal transmission circuits. Using this model, differential activation of such circuits between biological conditions can be estimated. Thus, circuit activation s…
Transcriptomic identification of miR-205 target genes potentially involved in metastasis and survival of cutaneous malignant melanoma
2020
AbstractCutaneous melanoma is an aggressive neoplasm and is responsible for the majority of skin cancer deaths. Several miRNAs are involved in melanoma tumor progression. One of them is miR-205, the loss of which contributes to the development of melanoma metastasis. We evaluated whole-genome mRNA expression profiling associated with different miR-205 expression levels in melanoma cells. Differential expression analysis identified 243 differentially expressed transcripts including inositol polyphosphate 5′-phosphatase-like protein-1 (INPPL1) and BTB/POZ Domain-Containing Protein 3 (BTBD3). INPPL1 and BTBD3 were downregulated when melanoma cells expressed miR-205, indicating that these genes…
The mitotic kinase Aurora-A promotes distant metastases by inducing epithelial-to-mesenchymal transition in ERα+ breast cancer cells
2013
In this study, we demonstrate that constitutive activation of Raf-1 oncogenic signaling induces stabilization and accumulation of Aurora-A mitotic kinase that ultimately drives the transition from an epithelial to a highly invasive mesenchymal phenotype in estrogen receptor α-positive (ERα(+)) breast cancer cells. The transition from an epithelial- to a mesenchymal-like phenotype was characterized by reduced expression of ERα, HER-2/Neu overexpression and loss of CD24 surface receptor (CD24(-/low)). Importantly, expression of key epithelial-to-mesenchymal transition (EMT) markers and upregulation of the stemness gene SOX2 was linked to acquisition of stem cell-like properties such as the ab…
Intrinsically disordered protein PID-2 modulates Z granules and is required for heritable piRNA-induced silencing in the Caenorhabditis elegans embryo
2020
Abstract In Caenorhabditis elegans, the piRNA (21U RNA) pathway is required to establish proper gene regulation and an immortal germline. To achieve this, PRG‐1‐bound 21U RNAs trigger silencing mechanisms mediated by RNA‐dependent RNA polymerase (RdRP)‐synthetized 22G RNAs. This silencing can become PRG‐1‐independent and heritable over many generations, a state termed RNA‐induced epigenetic gene silencing (RNAe). How and when RNAe is established, and how it is maintained, is not known. We show that maternally provided 21U RNAs can be sufficient for triggering RNAe in embryos. Additionally, we identify PID‐2, a protein containing intrinsically disordered regions (IDRs), as a factor required …
Aberrant methylation of tRNAs links cellular stress to neuro-developmental disorders.
2014
Mutations in the cytosine-5 RNA methyltransferase NSun2 cause microcephaly and other neurological abnormalities in mice and human. How post-transcriptional methylation contributes to the human disease is currently unknown. By comparing gene expression data with global cytosine-5 RNA methylomes in patient fibroblasts and NSun2-deficient mice, we find that loss of cytosine-5 RNA methylation increases the angiogenin-mediated endonucleolytic cleavage of transfer RNAs (tRNA) leading to an accumulation of 5' tRNA-derived small RNA fragments. Accumulation of 5' tRNA fragments in the absence of NSun2 reduces protein translation rates and activates stress pathways leading to reduced cell siz…
Small RNA‐binding protein RapZ mediates cell envelope precursor sensing and signaling in Escherichia coli
2019
Abstract The RNA‐binding protein RapZ cooperates with small RNAs (sRNAs) GlmY and GlmZ to regulate the glmS mRNA in Escherichia coli. Enzyme GlmS synthesizes glucosamine‐6‐phosphate (GlcN6P), initiating cell envelope biosynthesis. GlmZ activates glmS expression by base‐pairing. When GlcN6P is ample, GlmZ is bound by RapZ and degraded through ribonuclease recruitment. Upon GlcN6P depletion, the decoy sRNA GlmY accumulates through a previously unknown mechanism and sequesters RapZ, suppressing GlmZ decay. This circuit ensures GlcN6P homeostasis and thereby envelope integrity. In this work, we identify RapZ as GlcN6P receptor. GlcN6P‐free RapZ stimulates phosphorylation of the two‐component sy…
AP-1 Transcription Factor Serves as a Molecular Switch between Chlamydia pneumoniae Replication and Persistence
2015
ABSTRACT Chlamydia pneumoniae is a Gram-negative bacterium that causes acute or chronic respiratory infections. As obligate intracellular pathogens, chlamydiae efficiently manipulate host cell processes to ensure their intracellular development. Here we focused on the interaction of chlamydiae with the host cell transcription factor activator protein 1 (AP-1) and its consequence on chlamydial development. During Chlamydia pneumoniae infection, the expression and activity of AP-1 family proteins c-Jun, c-Fos, and ATF-2 were regulated in a time- and dose-dependent manner. We observed that the c-Jun protein and its phosphorylation level significantly increased during C. pneumoniae development.…