T-cells require post-transcriptional regulation for accurate immune responses

2015 ◽  
Vol 43 (6) ◽  
pp. 1201-1207 ◽  
Author(s):  
Fiamma Salerno ◽  
Monika C. Wolkers

Cytotoxic T-cells are crucial to protect us from intracellular pathogens and malignant cells. When T-cells become activated, they rapidly secrete cytokines, chemokines and cytotoxic granules that are critical to clear infected cells. However, when not properly regulated, these toxic effector molecules become one of the key mediators of autoimmune diseases. Therefore, a tight and multi-layered regulation of gene expression and protein production is required to ensure a protective yet balanced immune response. In this review, we describe how post-transcriptional events modulate the production of effector molecules in T-cells. In particular, we will focus on the role of cis-regulatory elements within the 3′-UTR of specific mRNAs and on RNA-binding proteins (RBPs) and non-coding RNAs that control the initiation and resolution of T-cell responses.

2018 ◽  
Author(s):  
Adam J. Litterman ◽  
Wandi S. Zhu ◽  
Robin Kageyama ◽  
Wenxue Zhao ◽  
Noah Zaitlen ◽  
...  

AbstractRNA binding proteins (RBPs) mediate constitutive RNA metabolism and gene specific regulatory interactions. To identify RNA cis-regulatory elements, we developed GCLiPP, a biochemical technique for detecting RBP occupancy transcriptome-wide. GCLiPP sequence tags corresponded with known RBP binding sites, specifically correlating to abundant cytosolic RBPs. To demonstrate the utility of our occupancy profiles, we performed functional dissection of 3′ UTRs with CRISPR/Cas9 genome editing. Two RBP occupied sites in the CD69 3′ UTR destabilized the transcript of this key regulator of lymphocyte tissue egress. Comparing human Jurkat T cells and mouse primary T cells uncovered hundreds of biochemically shared peaks of GCLiPP signal across homologous regions of human and mouse 3′ UTRs, including a cis-regulatory element that governs the stability of the mRNA that encodes the proto-oncogene PIM3 in both species. Our GCLiPP datasets provide a rich resource for investigation of post-transcriptional regulation in the immune system.


2020 ◽  
Vol 21 (18) ◽  
pp. 6835
Author(s):  
Jonas Weiße ◽  
Julia Rosemann ◽  
Vanessa Krauspe ◽  
Matthias Kappler ◽  
Alexander W. Eckert ◽  
...  

Nearly 7.5% of all human protein-coding genes have been assigned to the class of RNA-binding proteins (RBPs), and over the past decade, RBPs have been increasingly recognized as important regulators of molecular and cellular homeostasis. RBPs regulate the post-transcriptional processing of their target RNAs, i.e., alternative splicing, polyadenylation, stability and turnover, localization, or translation as well as editing and chemical modification, thereby tuning gene expression programs of diverse cellular processes such as cell survival and malignant spread. Importantly, metastases are the major cause of cancer-associated deaths in general, and particularly in oral cancers, which account for 2% of the global cancer mortality. However, the roles and architecture of RBPs and RBP-controlled expression networks during the diverse steps of the metastatic cascade are only incompletely understood. In this review, we will offer a brief overview about RBPs and their general contribution to post-transcriptional regulation of gene expression. Subsequently, we will highlight selected examples of RBPs that have been shown to play a role in oral cancer cell migration, invasion, and metastasis. Last but not least, we will present targeting strategies that have been developed to interfere with the function of some of these RBPs.


Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1539 ◽  
Author(s):  
Yogesh Saini ◽  
Jian Chen ◽  
Sonika Patial

Post-transcriptional regulation of gene expression plays a key role in cellular proliferation, differentiation, migration, and apoptosis. Increasing evidence suggests dysregulated post-transcriptional gene expression as an important mechanism in the pathogenesis of cancer. The tristetraprolin family of RNA-binding proteins (RBPs), which include Zinc Finger Protein 36 (ZFP36; commonly referred to as tristetraprolin (TTP)), Zinc Finger Protein 36 like 1 (ZFP36L1), and Zinc Finger Protein 36 like 2 (ZFP36L2), play key roles in the post-transcriptional regulation of gene expression. Mechanistically, these proteins function by binding to the AU-rich elements within the 3′-untranslated regions of their target mRNAs and, in turn, increasing mRNA turnover. The TTP family RBPs are emerging as key regulators of multiple biological processes relevant to cancer and are aberrantly expressed in numerous human cancers. The TTP family RBPs have tumor-suppressive properties and are also associated with cancer prognosis, metastasis, and resistance to chemotherapy. Herein, we summarize the various hallmark molecular traits of cancers that are reported to be regulated by the TTP family RBPs. We emphasize the role of the TTP family RBPs in the regulation of trait-associated mRNA targets in relevant cancer types/cell lines. Finally, we highlight the potential of the TTP family RBPs as prognostic indicators and discuss the possibility of targeting these TTP family RBPs for therapeutic benefits.


2014 ◽  
Vol 306 (6) ◽  
pp. F569-F576 ◽  
Author(s):  
Rudolf Pullmann ◽  
Hamid Rabb

The posttranscriptional regulation of gene expression occurs through cis RNA regulatory elements by the action of trans factors, which are represented by noncoding RNAs (especially microRNAs) and turnover- and translation-regulatory (TTR) RNA-binding proteins (RBPs). These multifactorial proteins are a group of heterogeneous RBPs primarily implicated in controlling the decay and translation rates of target mRNAs. TTR-RBPs usually shuttle between cellular compartments (the nucleus and cytoplasm) in response to various stimuli and undergo posttranslational modifications such as phosphorylation or methylation to ensure their proper subcellular localization and function. TTR-RBPs are emerging as key regulators of a wide variety of genes influencing kidney physiology and pathology. This review summarizes the current knowledge of TTR-RBPs that influence renal metabolism. We will discuss the role of TTR-RBPs as regulators of kidney ischemia, fibrosis and matrix remodeling, angiogenesis, membrane transport, immunity, vascular tone, hypertension, and acid-base balance as well as anemia, bone mineral disease, and vascular calcification.


2016 ◽  
Author(s):  
Alessandro Quattrone ◽  
Erik Dassi

AbstractRNA-binding proteins (RBPs) are key players of post-transcriptional regulation of gene expression. These proteins influence both cellular physiology and pathology by regulating processes ranging from splicing and polyadenylation to mRNA localization, stability, and translation. To fine-tune the outcome of their regulatory action, RBPs rely on an intricate web of competitive and cooperative interactions. Several studies have described individual interactions of RBPs with RBP mRNAs, suggestive of a RBP-RBP regulatory structure. Here we present the first systematic investigation of this structure, based on a network including almost fifty thousand experimentally determined interactions between RBPs and bound RBP mRNAs.Our analysis identified two features defining the structure of the RBP-RBP regulatory network. What we call “RBP clusters” are groups of densely interconnected RBPs which co-regulate their targets, suggesting a tight control of cooperative and competitive behaviors. “RBP chains”, instead, are hierarchical structures driven by evolutionarily ancient RBPs, which connect the RBP clusters and could in this way provide the flexibility to coordinate the tuning of a broad set of biological processes.The combination of these two features suggests that RBP chains may use the modulation of their RBP targets to coordinately control the different cell programs controlled by the RBP clusters. Under this island-hopping model, the regulatory signal flowing through the chains hops from one RBP cluster to another, implementing elaborate regulatory plans to impact cellular phenotypes. This work thus establishes RBP-RBP interactions as a backbone driving post-transcriptional regulation of gene expression to allow the fine-grained control of RBPs and their targets.


2016 ◽  
Author(s):  
Mireya Plass ◽  
Simon H. Rasmussen ◽  
Anders Krogh

AbstractBackgroundMicroRNAs (miRNAs) are endogenous short non-coding RNAs involved in the regulation of gene expression at the post-transcriptional level typically by promoting destabilization or translational repression of target RNAs. Sometimes this regulation is absent or different, which likely is the result of interactions with other post-transcriptional factors, particularly RNA-binding proteins (RBPs). Despite the importance of the interactions between RBPs and miRNAs, little is known about how they affect post-transcriptional regulation in a global scale.ResultsIn this study, we have analyzed CLIP datasets of 49 RBPs in HEK293 cells with the aim of understanding the interplay between RBPs and miRNAs in post-transcriptional regulation. Our results show that RBPs bind preferentially in conserved regulatory hotspots that frequently contain miRNA target sites. This organization facilitates the competition and cooperation among RBPs and the regulation of miRNA target site accessibility. In some cases RBP enrichment on target sites correlates with miRNA expression, suggesting coordination between the regulatory factors. However, in most cases, competition among factors is the most plausible interpretation of our data. Upon AGO2 knockdown, transcripts that contain such hotspots that overlap target sites of expressed miRNAs in 3’UTRs are significantly less up-regulated than transcripts without them, suggesting that RBP binding limits miRNA accessibility.ConclusionsWe show that RBP binding is concentrated in regulatory hotspots in 3’UTRs. The presence of these hotspots facilitates the interaction among post-transcriptional regulators, that interact or compete with each other under different conditions. These hotspots are enriched in genes with regulatory functions such as DNA binding and RNA binding. Taken together, our results suggest that hotspots are important regulatory regions that define an extra layer of auto-regulatory control of post-transcriptional regulation.


2020 ◽  
Author(s):  
Sibylle Mitschka ◽  
Christine Mayr

AbstractThe TP53 gene encodes the tumor suppressor p53, which is functionally inactivated in many human cancers. Numerous studies found that overexpression of specific microRNAs or RNA-binding proteins can alter p53 expression through binding to cis-regulatory elements in the TP53 3′ untranslated region (3′UTR). Although these studies suggested that 3′UTR-mediated p53 expression regulation could play a role in tumorigenesis or could be exploited for therapeutic purposes, they did not investigate post-transcriptional regulation of the native TP53 gene. We used CRISPR/Cas9 to delete the human and mouse p53 3′UTRs while preserving endogenous mRNA processing. This revealed that the endogenous 3′UTR is not involved in regulating p53 mRNA or protein expression neither in steady state nor after genotoxic stress. As we were able to confirm the previously observed repressive effects of the isolated 3′UTR in reporter assays, our data highlight the importance of genetic models in the validation of post-transcriptional gene regulatory effects.


2021 ◽  
Author(s):  
Nicholas S. Wilcox ◽  
Timur O. Yarovinsky ◽  
Prakruti Pandya ◽  
Vinod S. Ramgolam ◽  
Albertomaria Moro ◽  
...  

SummaryTissue homeostasis and repair are orchestrated by resident and newly recruited macrophages that alter their gene expression program in response to changes in tissue microenvironment. Embryonic macrophages, such as fetal liver derived macrophages (FLDM) seed the organs, including heart and lung during embryonic development and persist throughout the adult lifetime, while bone marrow-derived macrophages (BMDM) are recruited following an acute perturbation. Transcriptome analyses of FLDM and BMDM identified differences between them at the level of RNA expression, which correlates imperfectly with protein levels. Post-transcriptional regulation by microRNAs (miRNAs) and RNA-binding proteins determines mRNA stability and translation rate and may override transcriptional cues in response to environmental changes, such as hypoxia. To identify distinct features of FLDM and BMDM response to hypoxia at the level of translation, we employed translating ribosome affinity purification (TRAP) to isolate polysomal RNA. RNA-seq profiling of translated RNA identified distinct hypoxia-induced translational signature of BMDM (Ly6e, vimentin and glycolysis-associated enzymes Pgk1, Tpi1, Aldoa, Ldha) and FLDM (chemokines Ccl7 and Ccl2). By translational profiling of BMDM and FLDM with deletion of the RNA-binding protein HuR, we identified transcripts that were dependent on HuR. These findings highlight the importance of HuR and identify its distinct targets for post-transcriptional regulation of gene expression in embryonic vs. adult-derived macrophages.


2019 ◽  
Vol 166 (5) ◽  
pp. 375-382 ◽  
Author(s):  
Yutaro Uchida ◽  
Tomoki Chiba ◽  
Ryota Kurimoto ◽  
Hiroshi Asahara

Abstract In human genome, there are approximately 1,500 RNA-binding proteins (RBPs). They can regulate mRNA stability or translational efficiency via ribosomes and these processes are known as ‘post-transcriptional regulation’. Accumulating evidences indicate that post-transcriptional regulation is the determinant of the accurate levels of cytokines mRNAs. While transcriptional regulation of cytokines mRNAs has been well studied and found to be important for the rapid induction of mRNA and regulation of the acute phase of inflammation, post-transcriptional regulation by RBPs is essential for resolving inflammation in the later phase, and their dysfunction may lead to severe autoimmune diseases such as rheumatoid arthritis or systemic lupus erythematosus. For post-transcriptional regulation, RBPs recognize and directly bind to cis-regulatory elements in 3′ untranslated region of mRNAs such as AU-rich or constitutive decay elements and play various roles. In this review, we summarize the recent findings regarding the role of RBPs in the regulation of inflammation.


Author(s):  
Kent E. Duncan

Both RNA-binding proteins (RBPs) and translation are increasingly implicated in several neurodegenerative diseases, but their specific roles in promoting disease are not yet fully defined. This chapter critically evaluates the evidence that altered translation of specific mRNAs mediated by RNA-binding proteins plays an important role in driving specific neurodegenerative diseases. First, diseases are discussed where a causal role for RNA-binding proteins in disease appears solid, but whether this involves altered translation is less clear. The main foci here are TAR DNA-binding protein (TDP-43) and fused in sarcoma (FUS) in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Subsequently, diseases are presented where altered translation is believed to contribute, but involvement of RNA-binding proteins is less clear. These include Huntington’s and other repeat expansion disorders such as fragile X tremor/ataxia syndrome (FXTAS), where repeat-induced non-AUG-initiated (RAN) translation is a focus. The potential contribution of both canonical and non-canonical RBPs to altered translation in Parkinson’s disease is discussed. The chapter closes by proposing key research frontiers for the field to explore and outlining methodological advances that could help to address them.


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