Search results for " Biosynthesis"
showing 10 items of 317 documents
The 5' Untranslated Region of the
2018
Many of the virulence traits that make Candida albicans an important human fungal pathogen are regulated on a transcriptional level. Here, we report an important regulatory contribution of translation, which is exerted by the extensive 5′ untranslated regulatory sequence (5′ UTR) of the transcript for the protein Efg1, which determines growth, metabolism, and filamentation in the fungus. The presence of the 5′ UTR is required for efficient translation of Efg1, to promote filamentation. Because transcripts for many relevant regulators contain extensive 5′ UTR sequences, it appears that the virulence of C. albicans depends on the combination of transcriptional and translational regulatory mec…
Myelin Basic Protein synthesis is regulated by small non‐coding RNA 715
2012
Oligodendroglial Myelin Basic Protein (MBP) synthesis is essential for myelin formation in the central nervous system. During oligodendrocyte differentiation, MBP mRNA is kept in a translationally silenced state while intracellularly transported, until neuron-derived signals initiate localized MBP translation. Here we identify the small non-coding RNA 715 (sncRNA715) as an inhibitor of MBP translation. SncRNA715 localizes to cytoplasmic granular structures and associates with MBP mRNA transport granule components. We also detect increased levels of sncRNA715 in demyelinated chronic human multiple sclerosis lesions, which contain MBP mRNA but lack MBP protein.
Ythdf is a N6‐methyladenosine reader that modulates Fmr1 target mRNA selection and restricts axonal growth in Drosophila
2021
Abstract N6‐methyladenosine (m6A) regulates a variety of physiological processes through modulation of RNA metabolism. This modification is particularly enriched in the nervous system of several species, and its dysregulation has been associated with neurodevelopmental defects and neural dysfunctions. In Drosophila, loss of m6A alters fly behavior, albeit the underlying molecular mechanism and the role of m6A during nervous system development have remained elusive. Here we find that impairment of the m6A pathway leads to axonal overgrowth and misguidance at larval neuromuscular junctions as well as in the adult mushroom bodies. We identify Ythdf as the main m6A reader in the nervous system,…
tRNA-derived fragments: A new class of non-coding RNA with key roles in nervous system function and dysfunction
2021
tRNA-derived small RNAs (tsRNA) are a recently identified family of non-coding RNA that have been associated with a variety of cellular functions including the regulation of protein translation and gene expression. Recent sequencing and bioinformatic studies have identified the broad spectrum of tsRNA in the nervous system and demonstrated that this new class of non-coding RNA is produced from tRNA by specific cleavage events catalysed by ribonucleases such as angiogenin and dicer. Evidence is also accumulating that production of tsRNA is increased during disease processes where they regulate stress responses, proteostasis, and neuronal survival. Mutations to tRNA cleaving and modifying enz…
Genome Evolution in the Primary Endosymbiont of Whiteflies Sheds Light on Their Divergence
2015
International audience; Hemipteran insects are well-known in their ability to establish symbiotic relationships with bacteria. Among them, heteropteran insects present an array of symbiotic systems, ranging from the most common gut crypt symbiosis to the more restricted bacteriome-associated endosymbiosis, which have only been detected in members of the superfamily Lygaeoidea and the family Cimicidae so far. Genomic data of heteropteran endosymbionts are scarce and have merely been analyzed from the Wolbachia endosymbiont in bed bug and a few gut crypt-associated symbionts in pentatomoid bugs. In this study, we present the first detailed genomic analysis of a bacteriome-associated endosymbi…
Nm-23-H1 expression does not predict clinical survival in colorectal cancer patients
2003
The gene Nm23, which encodes for a nucleoside diphosphate kinase, has been defined as a metastasis-suppressor gene because of the inverse correlation between its expression and the metastatic capacity of the tumor cells. For colorectal cancer, however, the findings are equivocal. The aim of our study was to assess, in 160 patients undergoing surgery for colorectal cancer (CRC), the expression of the Nm23-H1 protein and to evaluate its possible associations with traditional clinicopathologic variables, with DNA-ploidy and proliferative activity (S-phase fraction, SPF), and with disease-free and overall survival of patients. Nm23-H1 expressions were evaluated on paraffin-embedded tissue by im…
Experimental techniques for testing the sensitivity of bladder tumours to antineoplastic drugs
1973
A number of laboratory tests can be employed to examine the sensitivity of human bladder tumour cells to various chemotherapeutic agents.-Their principles and methods, and some preliminary results, are described with special reference to certain in vitro and in vivo cytotoxicity tests and to heterotransplantation in the hamster. Satisfactory agreement has sometimes been observed between experimental results and clinical responses, but our experience is still very limited.-The employment of several such tests would probably lead to a greater degree of reliability in the laboratory assessment of the sensitivity of bladder tumours to cytotoxic drugs.
Nonsense-mediated mRNA decay controls the changes in yeast ribosomal protein pre-mRNAs levels upon osmotic stress.
2013
The expression of ribosomal protein (RP) genes requires a substantial part of cellular transcription, processing and translation resources. Thus, the RP expression must be tightly regulated in response to conditions that compromise cell survival. In Saccharomyces cerevisiae cells, regulation of the RP gene expression at the transcriptional, mature mRNA stability and translational levels during the response to osmotic stress has been reported. Reprogramming global protein synthesis upon osmotic shock includes the movement of ribosomes from RP transcripts to stress-induced mRNAs. Using tiling arrays, we show that osmotic stress yields a drop in the levels of RP pre-mRNAs in S. cerevisiae cell…
Beneficial Read-Through of aUSH1CNonsense Mutation by Designed Aminoglycoside NB30 in the Retina
2010
PURPOSE. The human Usher syndrome (USH) is the most frequent cause of inherited combined deaf-blindness. USH is clinically and genetically heterogeneous, assigned to three clinical types. The most severe type is USH1, characterized by profound inner ear defects and retinitis pigmentosa. Thus far, no effective treatment for the ophthalmic component of USH exists. The p.R31X nonsense mutation in USH1C leads to a disease causing premature termination of gene translation. Here, we investigated the capability of the novel synthetic aminoglycoside NB30 for the translational read-through of the USH1C-p.R31X nonsense mutation as a retinal therapy option. METHODS. Read-through of p.R31X by three com…
The nucleus negatively controls the synthesis of mitochondrial proteins in the sea urchin egg.
1983
Enucleation of Paracentrotus lividus eggs, followed by parthenogenetic activation induces a sharp increase in the synthesis of mitochondrial proteins as shown by electrofluorography after in vivo labeling with radioactive amino acids. These results further substantiate the hypothesis that the cell nucleus negatively controls mitochondrial replication in the sea urchin egg.