scholarly journals Phosphorylation of the RNA-binding protein Dazl by MAPKAP kinase 2 regulates spermatogenesis

2016 ◽  
Vol 27 (15) ◽  
pp. 2341-2350 ◽  
Author(s):  
Patrick A. Williams ◽  
Michael S. Krug ◽  
Emily A. McMillan ◽  
Jasmine D. Peake ◽  
Tara L. Davis ◽  
...  

Developing male germ cells are exquisitely sensitive to environmental insults such as heat and oxidative stress. An additional characteristic of these cells is their unique dependence on RNA-binding proteins for regulating posttranscriptional gene expression and translational control. Here we provide a mechanistic link unifying these two features. We show that the germ cell–specific RNA-binding protein deleted in azoospermia-like (Dazl) is phosphorylated by MAPKAP kinase 2 (MK2), a stress-induced protein kinase activated downstream of p38 MAPK. We demonstrate that phosphorylation of Dazl by MK2 on an evolutionarily conserved serine residue inhibits its interaction with poly(A)-binding protein, resulting in reduced translation of Dazl-regulated target RNAs. We further show that transgenic expression of wild-type human Dazl but not a phosphomimetic form in the Drosophila male germline can restore fertility to flies deficient in boule, the Drosophila orthologue of human Dazl. These results illuminate a novel role for MK2 in spermatogenesis, expand the repertoire of RNA-binding proteins phosphorylated by this kinase, and suggest that signaling by the p38-MK2 pathway is a negative regulator of spermatogenesis via phosphorylation of Dazl.

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 552
Author(s):  
Jasmine Harley ◽  
Benjamin E. Clarke ◽  
Rickie Patani

RNA binding proteins fulfil a wide number of roles in gene expression. Multiple mechanisms of RNA binding protein dysregulation have been implicated in the pathomechanisms of several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Oxidative stress and mitochondrial dysfunction also play important roles in these diseases. In this review, we highlight the mechanistic interplay between RNA binding protein dysregulation, oxidative stress and mitochondrial dysfunction in ALS. We also discuss different potential therapeutic strategies targeting these pathways.


1993 ◽  
Vol 13 (10) ◽  
pp. 6102-6113
Author(s):  
J T Anderson ◽  
M R Paddy ◽  
M S Swanson

Proteins that directly associate with nuclear polyadenylated RNAs, or heterogeneous nuclear RNA-binding proteins (hnRNPs), and those that associate with cytoplasmic mRNAs, or mRNA-binding proteins (mRNPs), play important roles in regulating gene expression at the posttranscriptional level. Previous work with a variety of eukaryotic cells has demonstrated that hnRNPs are localized predominantly within the nucleus whereas mRNPs are cytoplasmic. While studying proteins associated with polyadenylated RNAs in Saccharomyces cerevisiae, we discovered an abundant polyuridylate-binding protein, PUB1, which appears to be both an hnRNP and an mRNP. PUB1 and PAB1, the polyadenylate tail-binding protein, are the two major proteins cross-linked by UV light to polyadenylated RNAs in vivo. The deduced primary structure of PUB1 indicates that it is a member of the ribonucleoprotein consensus sequence family of RNA-binding proteins and is structurally related to the human hnRNP M proteins. Even though the PUB1 protein is a major cellular polyadenylated RNA-binding protein, it is nonessential for cell growth. Indirect cellular immunofluorescence combined with digital image processing allowed a detailed comparison of the intracellular distributions of PUB1 and PAB1. While PAB1 is predominantly, and relatively uniformly, distributed within the cytoplasm, PUB1 is localized in a nonuniform pattern throughout both the nucleus and the cytoplasm. The cytoplasmic distribution of PUB1 is considerably more discontinuous than that of PAB1. Furthermore, sucrose gradient sedimentation analysis demonstrates that PAB1 cofractionates with polyribosomes whereas PUB1 does not. These results suggest that PUB1 is both an hnRNP and an mRNP and that it may be stably bound to a translationally inactive subpopulation of mRNAs within the cytoplasm.


2020 ◽  
Vol 295 (42) ◽  
pp. 14291-14304
Author(s):  
Kathrin Bajak ◽  
Kevin Leiss ◽  
Christine Clayton ◽  
Esteban Erben

In Trypanosoma brucei and related kinetoplastids, gene expression regulation occurs mostly posttranscriptionally. Consequently, RNA-binding proteins play a critical role in the regulation of mRNA and protein abundance. Yet, the roles of many RNA-binding proteins are not understood. Our previous research identified the RNA-binding protein ZC3H5 as possibly involved in gene repression, but its role in controlling gene expression was unknown. We here show that ZC3H5 is an essential cytoplasmic RNA-binding protein. RNAi targeting ZC3H5 causes accumulation of precytokinetic cells followed by rapid cell death. Affinity purification and pairwise yeast two-hybrid analysis suggest that ZC3H5 forms a complex with three other proteins, encoded by genes Tb927.11.4900, Tb927.8.1500, and Tb927.7.3040. RNA immunoprecipitation revealed that ZC3H5 is preferentially associated with poorly translated, low-stability mRNAs, the 5′-untranslated regions and coding regions of which are enriched in the motif (U/A)UAG(U/A). As previously found in high-throughput analyses, artificial tethering of ZC3H5 to a reporter mRNA or other complex components repressed reporter expression. However, depletion of ZC3H5 in vivo caused only very minor decreases in a few targets, marked increases in the abundances of very stable mRNAs, an increase in monosomes at the expense of large polysomes, and appearance of “halfmer” disomes containing two 80S subunits and one 40S subunit. We speculate that the ZC3H5 complex might be implicated in quality control during the translation of suboptimal open reading frames.


2016 ◽  
Vol 12 (2) ◽  
pp. 532-540 ◽  
Author(s):  
Pritha Ghosh ◽  
R. Sowdhamini

We have classified the existing RNA-binding protein (RBP) structures into different structural families. Here, we report ∼2600 proteins with RBP signatures in humans.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Barbara Celona ◽  
John von Dollen ◽  
Sarat C Vatsavayai ◽  
Risa Kashima ◽  
Jeffrey R Johnson ◽  
...  

Expanded GGGGCC repeats in the first intron of the C9orf72 gene represent the most common cause of familial amyotrophic lateral sclerosis (ALS), but the mechanisms underlying repeat-induced disease remain incompletely resolved. One proposed gain-of-function mechanism is that repeat-containing RNA forms aggregates that sequester RNA binding proteins, leading to altered RNA metabolism in motor neurons. Here, we identify the zinc finger protein Zfp106 as a specific GGGGCC RNA repeat-binding protein, and using affinity purification-mass spectrometry, we show that Zfp106 interacts with multiple other RNA binding proteins, including the ALS-associated factors TDP-43 and FUS. We also show that Zfp106 knockout mice develop severe motor neuron degeneration, which can be suppressed by transgenic restoration of Zfp106 specifically in motor neurons. Finally, we show that Zfp106 potently suppresses neurotoxicity in a Drosophila model of C9orf72 ALS. Thus, these studies identify Zfp106 as an RNA binding protein with important implications for ALS.


2019 ◽  
Author(s):  
Keini Dressano ◽  
Philipp R Weckwerth ◽  
Elly Poretsky ◽  
Yohei Takahashi ◽  
Carleen Villarreal ◽  
...  

AbstractSurvival of all living organisms requires the ability to detect attack and swiftly counter with protective immune responses. Despite considerable mechanistic advances, interconnectivity of signaling circuits often remains unclear. A newly-characterized protein, IMMUNOREGULATORY RNA-BINDING PROTEIN (IRR), negatively regulates immune responses in both maize and Arabidopsis, with disrupted function resulting in enhanced disease resistance. IRR physically interacts with, and promotes canonical splicing of, transcripts encoding defense signaling proteins, including the key negative regulator of pattern recognition receptor signaling complexes, CALCIUM-DEPENDENT PROTEIN KINASE 28 (CPK28). Upon immune activation by Plant Elicitor Peptides (Peps), IRR is dephosphorylated, disrupting interaction withCPK28transcripts and resulting in accumulation of an alternative splice variant encoding a truncated CPK28 protein with impaired kinase activity and diminished function as a negative regulator. We demonstrate a novel circuit linking Pep-induced post-translational modification of IRR with post-transcriptionally-mediated attenuation of CPK28 function to dynamically amplify Pep signaling and immune output.One Sentence SummaryPlant innate immunity is promoted by post-translational modification of a novel RNA-binding protein that regulates alternative splicing of transcripts encoding defense signaling proteins to dynamically increase immune receptor signaling capacity through deactivation of a key signal-buffering circuit.


2018 ◽  
Author(s):  
Tim Schneider ◽  
Lee-Hsueh Hung ◽  
Masood Aziz ◽  
Anna Wilmen ◽  
Stephanie Thaum ◽  
...  

AbstractHow multidomain RNA-binding proteins recognize their specific target sequences, based on a combinatorial code, represents a fundamental unsolved question and has not been studied systematically so far. Here we focus on a prototypical multidomain RNA-binding protein, IMP3 (also called IGF2BP3), which contains six RNA-binding domains (RBDs): four KH and two RRM domains. We have established an integrative systematic strategy, combining single-domain-resolved SELEX-seq, motif-spacing analyses, in vivo iCLIP, functional validation assays, and structural biology. This approach identifies the RNA-binding specificity and RNP topology of IMP3, involving all six RBDs and a cluster of up to five distinct and appropriately spaced CA-rich and GGC-core RNA elements, covering a >100 nucleotide-long target RNA region. Our generally applicable approach explains both specificity and flexibility of IMP3-RNA recognition, providing a paradigm for the function of multivalent interactions with multidomain RNA-binding proteins in gene regulation.


2020 ◽  
Vol 56 (9) ◽  
pp. 1365-1368 ◽  
Author(s):  
Kouki Shinoda ◽  
Akiyo Suda ◽  
Kenko Otonari ◽  
Shiroh Futaki ◽  
Miki Imanishi

A new method manipulating local RNA methylation was developed by fusing the programmable RNA binding protein and the m6A demethylase or methyltransferase.


2006 ◽  
Vol 17 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Maria Paola Paronetto ◽  
Francesca Zalfa ◽  
Flavia Botti ◽  
Raffaele Geremia ◽  
Claudia Bagni ◽  
...  

Translational control plays a crucial role during gametogenesis in organisms as different as worms and mammals. Mouse knockout models have highlighted the essential function of many RNA-binding proteins during spermatogenesis. Herein we have investigated the expression and function during mammalian male meiosis of Sam68, an RNA-binding protein implicated in several aspects of RNA metabolism. Sam68 expression and localization within the cells is stage specific: it is expressed in the nucleus of spermatogonia, it disappears at the onset of meiosis (leptotene/zygotene stages), and it accumulates again in the nucleus of pachytene spermatocytes and round spermatids. During the meiotic divisions, Sam68 translocates to the cytoplasm where it is found associated with the polysomes. Translocation correlates with serine/threonine phosphorylation and it is blocked by inhibitors of the mitogen activated protein kinases ERK1/2 and of the maturation promoting factor cyclinB-cdc2 complex. Both kinases associate with Sam68 in pachytene spermatocytes and phosphorylate the regulatory regions upstream and downstream of the Sam68 RNA-binding motif. Molecular cloning of the mRNAs associated with Sam68 in mouse spermatocytes reveals a subset of genes that might be posttranscriptionally regulated by this RNA-binding protein during spermatogenesis. We also demonstrate that Sam68 shuttles between the nucleus and the cytoplasm in secondary spermatocytes, suggesting that it may promote translation of specific RNA targets during the meiotic divisions.


Blood ◽  
2011 ◽  
Vol 118 (22) ◽  
pp. 5732-5740 ◽  
Author(s):  
Maria Baou ◽  
John D. Norton ◽  
John J. Murphy

Abstract Posttranscriptional mechanisms are now widely acknowledged to play a central role in orchestrating gene-regulatory networks in hematopoietic cell growth, differentiation, and tumorigenesis. Although much attention has focused on microRNAs as regulators of mRNA stability/translation, recent data have highlighted the role of several diverse classes of AU-rich RNA-binding protein in the regulation of mRNA decay/stabilization. AU-rich elements are found in the 3′-untranslated region of many mRNAs that encode regulators of cell growth and survival, such as cytokines and onco/tumor-suppressor proteins. These are targeted by a burgeoning number of different RNA-binding proteins. Three distinct types of AU-rich RNA binding protein (ARE poly-U–binding degradation factor-1/AUF1, Hu antigen/HuR/HuA/ELAVL1, and the tristetraprolin/ZFP36 family of proteins) are essential for normal hematopoiesis. Together with 2 further AU-rich RNA-binding proteins, nucleolin and KHSRP/KSRP, the functions of these proteins are intimately associated with pathways that are dysregulated in various hematopoietic malignancies. Significantly, all of these AU-rich RNA-binding proteins function via an interconnected network that is integrated with microRNA functions. Studies of these diverse types of RNA binding protein are providing novel insight into gene-regulatory mechanisms in hematopoiesis in addition to offering new opportunities for developing mechanism-based targeted therapeutics in leukemia and lymphoma.


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