Search results for "H1°"

Oligodendroglioma cells synthesize the differentiation-specific linker histone H1˚ and release it into the extracellular environment through shed ves…

2013

Chromatin remodelling can be involved in some of the epigenetic modifications found in tumor cells. One of the mechanisms at the basis of chromatin dynamics is likely to be synthesis and incorporation of replacement histone variants, such as the H1° linker histone. Regulation of the expression of this protein can thus be critical in tumorigenesis. In developing brain, H1° expression is mainly regulated at the post-transcriptional level and RNA-binding proteins (RBPs) are involved. In the past, attention mainly focused on the whole brain or isolated neurons and little information is available on H1° expression in other brain cells. Even less is known relating to tumor glial cells. In this st…

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…

Identification in the rat brain of a set of nuclear proteins interacting with H1° mRNA

2012

Synthesis of H1° histone, in the developing rat brain, is also regulated at post-transcriptional level. Regulation of RNA metabolism depends on a series of RNA-binding proteins (RBPs); therefore, we searched for H1° mRNA-interacting proteins. With this aim, we used in vitro transcribed, biotinylated H1° RNA as bait to isolate, by a chromatographic approach, proteins which interact with this mRNA, in the nuclei of brain cells. Abundant RBPs, such as heterogeneous nuclear ribonucleoprotein (hnRNP) K and hnRNP A1, and molecular chaperones (heat shock cognate 70, Hsc70) were identified by mass spectrometry. Western blot analysis also revealed the presence of cold shock domain-containing protein…

RNA-binding proteins expressed in differentiating rat astrocytes

2012

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…

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…

Melanoma cells release extracellular vesicles which contain RNA-binding proteins able to bind the mRNA encoding histone H1°

2015

Extracellular vesicles (EVs) are produced by most prokaryotic and eukaryotic cells; tumour cells, however, release much higher amounts of EVs, which contain cancer-specific proteins and RNAs. Molecules carried by EVs are captured by surrounding cells, which then undergo profound phenotypic modifications. G26/24 oligodendroglioma cells release, for example, EVs containing FasL and TRAIL, which induce apoptosis in rat cortical neurons and astrocytes in culture. By metabolic labelling of cells, EV-mediated horizontal transfer of radioactive proteins was clearly demonstrated. Among the proteins present in EVs produced by oligodendroglioma cells, extracellular matrix remodelling proteases, and t…