26 research outputs found
Corrigendum: NFATc1 supports imiquimod-induced skin inflammation by suppressing IL-10 synthesis in B cells.
Nature Communications 7 Article number: 11724 doi: 10.1038/ncomms11724(2016); Published: 25 May 2016; Updated: 2 August 2016. The affiliation details for Amiya K. Patra are incomplete in this Article. The correct affiliations are given below: Institute of Translational and Stratified Medicine, Peninsula Schools of Medicine and Dentistry, University of Plymouth, Plymouth Science Park, Research Way, Plymouth PL6 8BU, UK
NFATc1 affects mouse splenic B cell function by controlling the calcineurināNFAT signaling network
Mouse B cells lacking NFATc1 exhibit defective proliferation, survival, isotype class switching, cytokine production, and T cell help
Prenylation inhibitors stimulate both estrogen receptor Ī± transcriptional activity through AF-1 and AF-2 and estrogen receptor Ī² transcriptional activity
INTRODUCTION: We showed in a previous study that prenylated proteins play a role in estradiol stimulation of proliferation. However, these proteins antagonize the ability of estrogen receptor (ER) Ī± to stimulate estrogen response element (ERE)-dependent transcriptional activity, potentially through the formation of a co-regulator complex. The present study investigates, in further detail, how prenylated proteins modulate the transcriptional activities mediated by ERĪ± and by ERĪ². METHODS: The ERE-Ī²-globin-Luc-SV-Neo plasmid was either stably transfected into MCF-7 cells or HeLa cells (MELN cells and HELN cells, respectively) or transiently transfected into MCF-7 cells using polyethylenimine. Cells deprived of estradiol were analyzed for ERE-dependent luciferase activity 16 hours after estradiol stimulation and treatment with FTI-277 (a farnesyltransferase inhibitor) or with GGTI-298 (a geranylgeranyltransferase I inhibitor). In HELN cells, the effect of prenyltransferase inhibitors on luciferase activity was compared after transient transfection of plasmids coding either the full-length ERĪ±, the full-length ERĪ², the AF-1-deleted ERĪ± or the AF-2-deleted ERĪ±. The presence of ERĪ± was then detected by immunocytochemistry in either the nuclei or the cytoplasms of MCF-7 cells. Finally, Clostridium botulinum C3 exoenzyme treatment was used to determine the involvement of Rho proteins in ERE-dependent luciferase activity. RESULTS: FTI-277 and GGTI-298 only stimulate ERE-dependent luciferase activity in stably transfected MCF-7 cells. They stimulate both ERĪ±-mediated and ERĪ²-mediated ERE-dependent luciferase activity in HELN cells, in the presence of and in the absence of estradiol. The roles of both AF-1 and AF-2 are significant in this effect. Nuclear ERĪ± is decreased in the presence of prenyltransferase inhibitors in MCF-7 cells, again in the presence of and in the absence of estradiol. By contrast, cytoplasmic ERĪ± is mainly decreased after treatment with FTI-277, in the presence of and in the absence of estradiol. The involvement of Rho proteins in ERE-dependent luciferase activity in MELN cells is clearly established. CONCLUSIONS: Together, these results demonstrate that prenylated proteins (at least RhoA, RhoB and/or RhoC) antagonize the ability of ERĪ± and ERĪ² to stimulate ERE-dependent transcriptional activity, potentially acting through both AF-1 and AF-2 transcriptional activities
The possible functions of duplicated ets (GGAA) motifs located near transcription start sites of various human genes
Transcription is one of the most fundamental nuclear functions and is an enzyme complex-mediated reaction that converts DNA sequences into mRNA. Analyzing DNA sequences of 5ā²-flanking regions of several human genes that respond to 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in HL-60 cells, we have identified that the ets (GGAA) motifs are duplicated, overlapped, or clustered within a 500-bp distance from the most 5ā²-upstream region of the cDNA. Multiple protein factors including Ets family proteins are known to recognize and bind to the GGAA containing sequences. In addition, it has been reported that the ets motifs play important roles in regulation of various promoters. Here, we propose a molecular mechanism, defined by the presence of duplication and multiplication of the GGAA motifs, that is responsible for the initiation of transcription of several genes and for the recruitment of binding proteins to the transcription start site (TSS) of TATA-less promoters
The impact of transposable element activity on therapeutically relevant human stem cells
Human stem cells harbor significant potential for basic and clinical translational research as well as regenerative
medicine. Currently ~ 3000 adult and ~ 30 pluripotent stem cell-based, interventional clinical trials are ongoing
worldwide, and numbers are increasing continuously. Although stem cells are promising cell sources to treat a
wide range of human diseases, there are also concerns regarding potential risks associated with their clinical use,
including genomic instability and tumorigenesis concerns. Thus, a deeper understanding of the factors and
molecular mechanisms contributing to stem cell genome stability are a prerequisite to harnessing their therapeutic
potential for degenerative diseases. Chemical and physical factors are known to influence the stability of stem cell
genomes, together with random mutations and Copy Number Variants (CNVs) that accumulated in cultured human
stem cells. Here we review the activity of endogenous transposable elements (TEs) in human multipotent and
pluripotent stem cells, and the consequences of their mobility for genomic integrity and host gene expression. We
describe transcriptional and post-transcriptional mechanisms antagonizing the spread of TEs in the human genome,
and highlight those that are more prevalent in multipotent and pluripotent stem cells. Notably, TEs do not only
represent a source of mutations/CNVs in genomes, but are also often harnessed as tools to engineer the stem cell
genome; thus, we also describe and discuss the most widely applied transposon-based tools and highlight the
most relevant areas of their biomedical applications in stem cells. Taken together, this review will contribute to the
assessment of the risk that endogenous TE activity and the application of genetically engineered TEs constitute for
the biosafety of stem cells to be used for substitutive and regenerative cell therapiesS.R.H. and P.T.R. are funded by the Government of Spain (MINECO, RYC-2016-
21395 and SAF2015ā71589-P [S.R.H.]; PEJ-2014-A-31985 and SAF2015ā71589-
P [P.T.R.]). GGS is supported by a grant from the Ministry of Health of the
Federal Republic of Germany (FKZ2518FSB403)
Architecture and expression of the Nfatc1 gene in lymphocytes
In lymphocytes, the three NFAT factors NFATc1 (also designated as NFAT2), NFATc2 (NFAT1), and NFATc3 (NFAT4 or NFATx) are expressed and are the targets of immune receptor signals, which lead to a rapid rise of intracellular Ca++, the activation of phosphatase calcineurin, and to the activation of cytosolic NFATc proteins. In addition to rapid activation of NFAT factors, immune receptor signals lead to accumulation of the short NFATc1/Ī±A isoform in lymphocytes which controls their proliferation and survival. In this mini-review, we summarize our current knowledge on the structure and transcription of the Nfatc1 gene in lymphocytes, which is controlled by two promoters, two poly A addition sites and a remote downstream enhancer. The Nfatc1 gene resembles numerous primary response genes (PRGs) induced by LPS in macrophages. Similar to the PRG promoters, the Nfatc1 promoter region is organized in CpG islands, forms DNase I hypersensitive sites, and is marked by histone tail modifications before induction. By studying gene induction in lymphocytes in detail, it will be important to elucidate whether the properties of the Nfatc1 induction are not only typical for the Nfatc1 gene but also for other transcription factor genes expressed in lymphocytes