Search results for "RNA-Binding Protein"

Annexin II is present on renal epithelial cells and binds calcium oxalate monohydrate crystals.

2003

Attachment of newly formed crystals to renal epithelial cells appears to be a critical step in the development of kidney stones. The current study was undertaken to identify potential calcium oxalate monohydrate (COM) crystal-binding proteins on the surface of renal tubular cells. Apical membranes were prepared from confluent monolayers of renal epithelial cells (MDCKI line), and COM crystal affinity was used to isolate crystal-binding proteins that were then subjected to electrophoresis and electroblotting. Microsequencing of the most prominent COM crystal-binding protein (M(r) of 37 kD) identified it as annexin II (Ax-II). When exposed proteins on the surface of intact monolayers were bio…

The RNA binding protein tristetraprolin influences the activation state of murine dendritic cells

2010

Abstract Dendritic cells (DCs) serve to maintain peripheral tolerance under steady state conditions. Upon triggering by activation signals they initiate strong immune responses. The activation of DCs is accompanied by a rapid upregulation of proinflammatory cytokines, which were shown in other cell types to be regulated by mechanisms at the transcriptional and posttranscriptional level. Tristetraprolin (TTP), an important RNA binding protein, is involved in the regulation of mRNA stability of such cytokines. In this study we analyzed the significance of TTP for mouse DCs, which were derived from TTP −/− and WT bone marrow progenitor cells (BM-DCs). Unstimulated BM-DCs of TTP −/− mice expres…

GW-Bodies and P-Bodies Constitute Two Separate Pools of Sequestered Non-Translating RNAs

2015

Non-translating RNAs that have undergone active translational repression are culled from the cytoplasm into P-bodies for decapping-dependent decay or for sequestration. Organisms that use microRNA-mediated RNA silencing have an additional pathway to remove RNAs from active translation. Consequently, proteins that govern microRNA-mediated silencing, such as GW182/Gw and AGO1, are often associated with the P-bodies of higher eukaryotic organisms. Due to the presence of Gw, these structures have been referred to as GW-bodies. However, several reports have indicated that GW-bodies have different dynamics to P-bodies. Here, we use live imaging to examine GW-body and P-body dynamics in the early …

Two Enhancers Control Transcription of Drosophila muscleblind in the Embryonic Somatic Musculature and in the Central Nervous System

2014

The phylogenetically conserved family of Muscleblind proteins are RNA-binding factors involved in a variety of gene expression processes including alternative splicing regulation, RNA stability and subcellular localization, and miRNA biogenesis, which typically contribute to cell-type specific differentiation. In humans, sequestration of Muscleblind-like proteins MBNL1 and MBNL2 has been implicated in degenerative disorders, particularly expansion diseases such as myotonic dystrophy type 1 and 2. Drosophila muscleblind was previously shown to be expressed in embryonic somatic and visceral muscle subtypes, and in the central nervous system, and to depend on Mef2 for transcriptional activatio…

EFFECTS OF THYROID HORMONES ON TWO PUTATIVE RNA-BINDING PROTEINS EXPRESSED IN DEVELOPING RAT BRAIN.

2005

Fertility and Polarized Cell Growth Depends on eIF5A for Translation of Polyproline-Rich Formins in Saccharomyces cerevisiae

2014

eIF5A is an essential and evolutionary conserved translation elongation factor, which has recently been proposed to be required for the translation of proteins with consecutive prolines. The binding of eIF5A to ribosomes occurs upon its activation by hypusination, a modification that requires spermidine, an essential factor for mammalian fertility that also promotes yeast mating. We show that in response to pheromone, hypusinated eIF5A is required for shmoo formation, localization of polarisome components, induction of cell fusion proteins, and actin assembly in yeast. We also show that eIF5A is required for the translation of Bni1, a proline-rich formin involved in polarized growth during …

Involvement of KSRP in the post-transcriptional regulation of human iNOS expression–complex interplay of KSRP with TTP and HuR

2005

We purified the KH-type splicing regulatory protein (KSRP) as a protein interacting with the 3'-untranslated region (3'-UTR) of the human inducible nitric oxide (iNOS) mRNA. Immunodepletion of KSRP enhanced iNOS 3'-UTR RNA stability in in vitro-degradation assays. In DLD-1 cells overexpressing KSRP cytokine-induced iNOS expression was markedly reduced. In accordance, downregulation of KSRP expression increases iNOS expression by stabilizing iNOS mRNA. Co-immunoprecipitations showed interaction of KSRP with the exosome and tristetraprolin (TTP). To analyze the role of KSRP binding to the 3'-UTR we studied iNOS expression in DLD-1 cells overexpressing a non-binding mutant of KSRP. In these ce…

Translocation (10;11;22)(p14;q24;q12) Characterized by Fluorescence in Situ Hybridization in a Case of Ewing's Tumor

2001

It is well recognized that the identification by classic cytogenetics of t(11;22)(q24;q12) is a useful aid in the accurate diagnosis of Ewing's sarcoma and related tumors. This translocation induces the EWS/FLI-1 fusion transcript, which can be detected by reverse transcription-polymerase chain reaction. Recent studies have also used fluorescence in situ hybridization (FISH) to demonstrate the translocation. The authors coupled classic cytogenetics and FISH on tumor cells from the original specimen, the local recurrence, and the pulmonary metastasis as well as from the xenografted tumors in a case of extraosseous Ewing's sarcoma. FISH analysis not only confirmed the cytogenetic results but …

Nuclear-mitochondrial interaction.

2007

The biogenesis of mitochondria depends on the coordinated expression of nuclear and mitochondrial genomes. Consequently, the control of mitochondrial biogenesis and function depends on extremely complex processes requiring a variety of well orchestrated regulatory mechanisms. It is clear that the interplay of transcription factors and coactivators contributes to the expression of both nuclear and mitochondrial respiratory genes. In addition, the regulation of mitochondria biogenesis depends on proteins that, interacting with messenger RNAs for mitochondrial proteins, influence their metabolism and expression. Moreover, a tight regulation of the import and final assembly of mitochondrial pro…

rbFOX1/MBNL1 competition for CCUG RNA repeats binding contributes to myotonic dystrophy type 1/type 2 differences

2018

Myotonic dystrophy type 1 and type 2 (DM1, DM2) are caused by expansions of CTG and CCTG repeats, respectively. RNAs containing expanded CUG or CCUG repeats interfere with the metabolism of other RNAs through titration of the Muscleblind-like (MBNL) RNA binding proteins. DM2 follows a more favorable clinical course than DM1, suggesting that specific modifiers may modulate DM severity. Here, we report that the rbFOX1 RNA binding protein binds to expanded CCUG RNA repeats, but not to expanded CUG RNA repeats. Interestingly, rbFOX1 competes with MBNL1 for binding to CCUG expanded repeats and overexpression of rbFOX1 partly releases MBNL1 from sequestration within CCUG RNA foci in DM2 muscle ce…