Search results for "RBPs"
showing 10 items of 12 documents
Extracellular Vesicles Shed by Melanoma Cells Contain a Modified Form of H1.0 Linker Histone and H1.0 mRNA-binding Proteins
2016
Extracellular vesicles (EVs) are shed in the extracellular environment by both prokaryotes and eukaryotes. Although produced from both normal and cancer cells, malignant cells release a much higher amount of EVs, which also contain tumor-specific proteins and RNAs. We previously found that G26/24 oligodendroglioma cells shed EVs that contain the pro-apoptotic factors FasL and TRAIL1-2. Interestingly, G26/24 release, via EVs, extracellular matrix remodelling proteases3, and H1° histone protein4, and mRNA. To shed further light on the role of EVs in discarding proteins and mRNAs otherwise able to counteract proliferative signals, we studied a melanoma cell line (A375). We found that also thes…
Extracellular Vesicle‐Associated RNA as a Carrier of Epigenetic Information
2017
Post-transcriptional regulation of messenger RNA (mRNA) metabolism and subcellular localization is of the utmost importance both during development and in cell differentiation. Besides carrying genetic information, mRNAs contain cis-acting signals (zip codes), usually present in their 5'- and 3'-untranslated regions (UTRs). By binding to these signals, trans-acting factors, such as RNA-binding proteins (RBPs), and/or non-coding RNAs (ncRNAs), control mRNA localization, translation and stability. RBPs can also form complexes with non-coding RNAs of different sizes. The release of extracellular vesicles (EVs) is a conserved process that allows both normal and cancer cells to horizontally tran…
Retinol oxidation to retinoic acid in human thyroid glandular cells.
2014
Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its …
Identification of nuclear proteins which interact with H1° mRNA.
2012
In developing rat brain the synthesis of H1° histone is mainly regulated at posttranscriptional level and probably depends on RNA-binding proteins (RBPs) (1). We previously identified RBPs apparently specific for this messenger (2) and cloned two novel proteins by screening an expression cDNA library by binding to radiolabeled RNA (3-10). Here we report the use of biotinylated H1° RNA as bait to isolate by chromatography nuclear proteins which interact with H1° mRNA. We identified by mass spectrometry abundant RBPs and molecular chaperones. By western blot we also evidenced, among the RNA-bound proteins, the cold shock domain-containing protein 2 (CSD-C2, also know as PIPPin), a brain-enric…
ROLE OF RNA BINDING PROTEIN IN THE NERVE CELL DIFFERENTIATION
2014
Synthesis of H1˚ and H3.3 histone proteins, in the developing rat brain, seems to be regulated mainly at the post-transcriptional level. Since regulation of RNA metabolism depends on a series of RNA-binding proteins (RBPs), we have been searching for RBPs involved in the post-transcriptional regulation of the H1˚ and H3.3 genes. Previously, we reported isolation, from a cDNA expression library, of an insert encoding a novel protein, the C-terminal half of which is identical to that of PEP-19, a brain-specific protein involved in calcium metabolism. The novel protein was called long PEP-19 isoform (LPI). We showed that LPI, as well as PEP-19, can bind H1˚ RNA. Since PEP19 and LPI contain a c…
Developing rat brain as well as cultured astrocytes contain H1° mRNA-protein complexes
2015
RNA-binding proteins (RBPs) regulate intracellular transport, pre-localization, stability, and translation of mRNAs [1]. We previously identified a set of proteins which interact with mRNAs encoding H1° and H3.3 histones [2-5]. All these proteins are probably part of a ribonucleoprotein particle [6]. Here we report the results of a more detailed study on the expression and intracellular localization of some of these RBPs, such as hnRNP K and A1, and Hsc70, during rat brain development and in cultured rat astrocytes. We also investigated the presence in the complexes of PIPPin/CSD-C2 protein. Affinity chromatography was performed as already described [6]. Preparation of total lysates and cel…
H1° mRNA-containing complexes in rat brain cells. In: Proceedings of the Abstracts
2015
Post-transcriptional regulation of gene expression depends on RNA-binding proteins (RBPs), which are able to regulate translation, stability and subcellular localization of mRNAs [1]. RNA-protein complexes start to be built up since transcription; some proteins remain then bound to the transcript, while others behave as only transient components. In the developing nervous system of mammals, the postnatal production of the histone variants H1° and H3.3 is mainly regulated at the post-transcriptional level. Synthesis and incorporation into chromatin of the two histone proteins has been suggested to be involved in the epigenetic regulation of gene expression, both in normal brain development a…
Melanoma cells release extracellular vesicle which contain H1° linker histone as well as RNA-binding proteins which bind to the H1° mRNA
2015
We previously demonstrated that G26/24 oligodendroglioma cells release EVs that contain proteins, such as FasL and TRAIL, which induce apoptosis in rat cortical neurons [1] and astrocytes [2]. We also reported that cancer cells use EVs for transferring, into the environment [3], proteins such as extracellular matrix remodelling proteases [4], and H1°, a differentiation-specific histone [5]. In particular, by releasing H1°, cells could escape differentiation cues [5]. To verify the role of EVs in releasing specific proteins and mRNAs, in this study we used as a model A375 melanoma cells. METHODS EVs were purified from cell culture media as previously reported [1, 2]. T1 RNase-protection assa…
Expression and intracellular localization of H1° mRNA-containing complexes in developing rat brain and astrocytes
2015
INTRODUCTION: Post-transcriptional regulation of gene expression relies on RNA-binding proteins (RBPs), which regulate intracellular transport, stability, and translation of mRNAs [1]. We previously identified a set of proteins which interact with mRNAs encoding H1° and H3.3 histones [2-5]. All these proteins are probably part of a ribonucleoprotein particle [6]. Here we report more details on the expression and intracellular localization of some of these RBPs, during rat brain development and in isolated rat astrocytes. METHODS: Affinity chromatography was performed as already described [6]. Preparation of total lysates and cellular sub-fractions was done as reported in [3]. Possible co-lo…
Extracellular membrane vesicles can mediate intercellular transfer of molecules
2012
Many eukaryotic cell types, including neural cells, release into the extracellular environment vesicles of different sizes and composition. Neurons and astrocytes shed extracellular vesicles which contain FGF2 and VEGF and could be involved in interaction with endothelial cells, to form the blood-brain barrier. Also brain tumor cells, such as glioblastomas, release vesicles in the extracellular space. Microvesicles (MVs) shed from G26/24 oligodendro¬glioma cells were previously reported to contain FAS-L and to cause a reproducible, dose-dependent, inhibitory effect on neurite outgrowth, and neuronal apoptosis, when added to primary cultures of rat cortical neurons. More recently, they were …