Search results for "Pippin"

Biological effects of inorganic arsenic on primary cultures of rat astrocytes

2010

It is well established that inorganic arsenic induces neurotoxic effects and neurological defects in humans and laboratory animals. The cellular and molecular mechanisms of its actions, however, remain elusive. Herein we report the effects of arsenite (NaAsO2) on primary cultures of rat astrocytes. Cells underwent induction of heat shock protein 70 only at the highest doses of inorganic arsenic (30 and 60 microM), suggesting a high threshold to respond to stress. We also investigated arsenic genotoxicity with the comet assay. Interestingly, although cells treated with 10 microM arsenite for 24 h maintained >70% viability, with respect to untreated cells, high DNA damage was already observed…

The effect of cadmium on brain cells in culture

2009

Cadmium is a long-living heavy metal, abundantly present in the environment, which accumulates in the body. In this study, we investigated the effects of cadmium on the expression of molecular chaperones, and of certain cell-specific proteins, in a variety of brain cell types in culture, namely primary cultures of rat cortical neurons and astrocytes, a brain capillary endothelial cell line (RB4E.B cells), and pheochromocytoma cells (PC12), induced or not to differentiate by NGF treatment. The metal induces a dose-dependent increase of Hsp70 in all cell types. Responses to the metal are cell-specific in the case of Hsc70 and Hsp90: i) in astrocytes, as well as in PC12 cells, cadmium has no s…

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…

RNAbinding proteins involved in nerve cell differentiation.

2009

Pippin protein expression changes during cell differentiation

2008

PIPPin is a CSD-containing protein with the ability to interact both with mRNAs encoding histone variants and chromatin. A major fraction of chromatin-bound PIPPin is sumoylated and sumoylation seems to be controlled by thyroid hormones, both in vivo and in vitro. We studied its expression in different tissues and cell lines and even in tumor cells and found that, even if more expressed in the brain respect to other tissues of the adult rat, it is also expressed in brain tumors and in cell lines as different as kidney NRK cells and PC12. The expression of the protein is strongly increased by treatments that induce differentiation, such as treatment of PC12 with NGF. We also found an increas…

PIPPIN SUMOYLATION IS CONTROLLED BY THYROID HORMONES

2006

EXPRESSION OF PIPPIN PROTEIN AND CELL DIFFERENTIATION.

2008

We previously described a CSD-containing protein that seemed to bind mRNAs encoding histone variants and was present both in the nucleus and in the cytoplasm of specific populations of brain cells. Since other CSD-containing proteins have the ability to interact both with RNA and chromatin, we investigated the possibility that PIPPin binds to chromatin and indeed found that about 50% of nuclear PIPPin cannot be extracted from nuclei with salt and is instead extracted with acid, together with histones. Interestingly, a major fraction of chromatin-bound PIPPin is sumoylated and sumoylation seems to be controlled by thyroid hormones, both in vivo and in vitro. In order to study the functions o…

RNA-binding ability of PIPP in requires the entire protein

2003

Post-transcriptional fate of eukaryotic mRNAs depends on association with different classes of RNA-binding proteins (RBPs). Among these proteins, the cold-shock domain (CSD)-containing proteins, also called Y-box proteins, play a key role in controlling the recruitment of mRNA to the translational machinery, in response to environmental cues, both in development and in differentiated cells. We recently cloned a rat cDNA encoding a new CSD-protein that we called PIPPin. This protein also contains two putative double-stranded RNA-binding motifs (PIP(1) and PIP(2)) flanking the central CSD, and is able to bind mRNAs encoding H1 degrees and H3.3 histone variants. In order to clarify the role of…

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…

Rat PIPPin is probably part of a large complex of RNA-binding proteins

2012

Throughout rat brain development, expression of histones variants is mainly regulated at the post-transcriptional level. We previously cloned two cDNAs encoding, respectively, PIPPin (or CSD-C2), a brain-enriched protein able to bind the 3’end of H1° and H3.3 mRNAs, and LPI (longer isoform of PEP-19). Both PEP-19 and LPI are brain-specific. By western blot, we found that PIPPin expression in PC12 cells is enhanced by NGF-induced differentiation. We investigated the RNA-binding properties of the three proteins using their 6 histidine-tagged recombinant fusions and found that they all bind H1° and H3.3 RNAs. Since PEP-19 and LPI are camstatins, we also analyzed whether calmodulin could interf…