U7 snRNA is part of the U7 snRNP complex, required for the 3' end processing of replication-dependent histone pre-mRNAs in S phase of the cell cycle. Here, we show that U7 snRNA plays another function in inhibiting the expression of a subset of long terminal repeats of human endogenous retroviruses (HERV1/LTR12s) and LTR12-containing long intergenic noncoding RNAs (lincRNAs), both bearing sequence motifs that perfectly match the 5' end of U7 snRNA. We demonstrate that U7 snRNA inhibits LTR12 and lincRNA transcription and propose a mechanism in which U7 snRNA hampers the binding/activity of the NF-Y transcription factor to CCAAT motifs within LTR12 elements.
View Article and Find Full Text PDFRetrotransposition is one of the main factors responsible for gene duplication and thus genome evolution. However, the sequences that undergo this process are not only an excellent source of biological diversity, but in certain cases also pose a threat to the integrity of the DNA. One of the mechanisms that protects against the incorporation of mobile elements is the HUSH complex, which is responsible for silencing long, intronless, transcriptionally active transposed sequences that are rich in adenine on the sense strand.
View Article and Find Full Text PDFHead and neck squamous cell carcinoma is one of the most common and fatal cancers worldwide. Lack of appropriate preventive screening tests, late detection, and high heterogeneity of these tumors are the main reasons for the unsatisfactory effects of therapy and, consequently, unfavorable outcomes for patients. An opportunity to improve the quality of diagnostics and treatment of this group of cancers are microRNAs (miRNAs) - molecules with a great potential both as biomarkers and therapeutic targets.
View Article and Find Full Text PDFRetroposed protein-coding genes are commonly considered to be nonfunctional duplicates. However, they often gain transcriptional capability and have important roles. Amici et al.
View Article and Find Full Text PDFAs it is well known, messenger RNA has many regulatory regions along its sequence length. One of them is the 5' untranslated region (5'UTR), which itself contains many regulatory elements such as upstream ORFs (uORFs), internal ribosome entry sites (IRESs), microRNA binding sites, and structural components involved in the regulation of mRNA stability, pre-mRNA splicing, and translation initiation. Activation of the alternative, more upstream transcription start site leads to an extension of 5'UTR.
View Article and Find Full Text PDFGut microbiota succession overlaps with intensive growth in infancy and early childhood. The multitude of functions performed by intestinal microbes, including participation in metabolic, hormonal, and immune pathways, makes the gut bacterial community an important player in cross-talk between intestinal processes and growth. Long-term disturbances in the colonization pattern may affect the growth trajectory, resulting in stunting or wasting.
View Article and Find Full Text PDFRetroposition is RNA-based gene duplication leading to the creation of single exon nonfunctional copies. Nevertheless, over time, many of these duplicates acquire transcriptional capabilities. In human in most cases, these so-called retrogenes do not code for proteins but function as regulatory long noncoding RNAs (lncRNAs).
View Article and Find Full Text PDFDespite the number of studies focused on sense-antisense transcription, the key question of whether such organization evolved as a regulator of gene expression or if this is only a byproduct of other regulatory processes has not been elucidated to date. In this study, protein-coding sense-antisense gene pairs were analyzed with a particular focus on pairs overlapping at their 5' ends. Analyses were performed in 73 human transcription start site libraries.
View Article and Find Full Text PDFLong noncoding RNAs (lncRNAs) have emerged as prominent regulators of gene expression in eukaryotes. The identification of lncRNA orthologs is essential in efforts to decipher their roles across model organisms, as homologous genes tend to have similar molecular and biological functions. The relatively high sequence plasticity of lncRNA genes compared with protein-coding genes, makes the identification of their orthologs a challenging task.
View Article and Find Full Text PDFBackground: Long noncoding RNAs represent a large class of transcripts with two common features: they exceed an arbitrary length threshold of 200 nt and are assumed to not encode proteins. Although a growing body of evidence indicates that the vast majority of lncRNAs are potentially nonfunctional, hundreds of them have already been revealed to perform essential gene regulatory functions or to be linked to a number of cellular processes, including those associated with the etiology of human diseases. To better understand the biology of lncRNAs, it is essential to perform a more in-depth study of their evolution.
View Article and Find Full Text PDFWaterlogging (WL), excess water in the soil, is a phenomenon often occurring during plant cultivation causing low oxygen levels (hypoxia) in the soil. The aim of this study was to identify candidate genes involved in long-term waterlogging tolerance in cucumber using RNA sequencing. Here, we also determined how waterlogging pre-treatment (priming) influenced long-term memory in WL tolerant (WL-T) and WL sensitive (WL-S) i.
View Article and Find Full Text PDFA large portion of the human genome is transcribed into long noncoding RNAs that can range from 200 nucleotides to several kilobases in length. The number of identified lncRNAs is still growing, but only a handful of them have been functionally characterized. However, it is known that the functions of lncRNAs are closely related to their subcellular localization.
View Article and Find Full Text PDFGene duplication is a major driver of organismal evolution. One of the main mechanisms of gene duplications is retroposition, a process in which mRNA is first transcribed into DNA and then reintegrated into the genome. Most gene retrocopies are depleted of the regulatory regions.
View Article and Find Full Text PDFMost genomes are populated by hundreds of thousands of sequences originated from mobile elements. On the one hand, these sequences present a real challenge in the process of genome analysis and annotation. On the other hand, they are very interesting biological subjects involved in many cellular processes.
View Article and Find Full Text PDFA substantial fraction of the human transcriptome is composed of the so-called long noncoding RNAs (lncRNAs), yet the available catalogs of known lncRNAs are far from complete. Moreover, functional studies of these RNAs are challenged by several factors, such as their tissue-specific expression and functional heterogeneity, resulting in only ca. 1% of them being well characterized.
View Article and Find Full Text PDFLong non-coding RNAs (lncRNAs) are a class of potent regulators of gene expression that are found in a wide array of eukaryotes; however, our knowledge about these molecules in plants is very limited. In particular, a number of plant species with important roles in biotechnology, agriculture and basic research still lack comprehensively identified and annotated sets of lncRNAs. To address these shortcomings, we previously created a database of lncRNAs in 10 model species, called CANTATAdb, and now we are expanding this online resource to encompass 39 species, including three algae.
View Article and Find Full Text PDFBacteria belonging to the genera and are responsible for significant economic losses in a wide variety of crops and ornamentals. During last years, increasing losses in potato production have been attributed to the appearance of . The strains investigated so far share genetic homogeneity, although different virulence levels were observed among strains of various origins.
View Article and Find Full Text PDFEpigenetic mechanisms play an important role in the development and progression of various neurodegenerative diseases. Abnormal methylation of numerous genes responsible for regulation of transcription, DNA replication, and apoptosis has been linked to Alzheimer's disease (AD) pathology. We have recently performed whole transcriptome profiling of familial early-onset Alzheimer's disease (fEOAD) patient-derived fibroblasts.
View Article and Find Full Text PDFThe BRCA1 protein, one of the major players responsible for DNA damage response has recently been linked to Alzheimer's disease (AD). Using primary fibroblasts and neurons reprogrammed from induced pluripotent stem cells (iPSC) derived from familial AD (FAD) patients, we studied the role of the BRCA1 protein underlying molecular neurodegeneration. By whole-transcriptome approach, we have found wide range of disturbances in cell cycle and DNA damage response in FAD fibroblasts.
View Article and Find Full Text PDFProximal promoter regions (PPR) are heavily transcribed yielding different types of small RNAs. The act of transcription within PPRs might regulate downstream gene expression via transcriptional interference (TI). For analysis, we investigated capped and polyadenylated small RNA transcripts within PPRs of human RefSeq genes in eight different cell lines.
View Article and Find Full Text PDFGene overlap plays various regulatory functions on transcriptional and post-transcriptional levels. Most current studies focus on protein-coding genes overlapping with non-protein-coding counterparts, the so called natural antisense transcripts. Considerably less is known about the role of gene overlap in the case of two protein-coding genes.
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