A Zebrafish Model for Selenoprotein Synthesis and Function (OR11-01-19)

Abstract Objectives We have established a zebrafish model system that will allow unprecedented access to the role of selenoprotein function during development. The work described here focuses on a poorly characterized RNA binding protein that is similar to SECIS binding protein 2 (SBP2), which is required for the co-translational insertion of selenocysteine at select UGA codons in selenoprotein mRNAs. This protein, SECISBP2L, shares many features with SBP2 but is has no known function. We hypothesize that the zebrafish model system will reveal a selenoprotein-synthesis related function for SECISBP2L. Methods Using CRISPR/Cas9, we generated zebrafish with a disruption in one of the conserved domains in SECISBP2L. When bred out to a homozygous mutant animal, we verified that SECISBP2L protein expression was eliminated. To analyze selenoprotein synthesis, we metabolically labeled wild-type and mutant embryos with radioactive selenium (Se-75). Results In terms of overt phenotypes in SECISBP2L null fish, we observed no defects in growth, mobility or fertility. However, we noticed a significant sensitivity to oxidative stress as measured by lethality associated with peroxide exposure. In order to detect changes in selenoprotein expression that may have resulted from SECISBP2L loss, we performed Se-75 labeling in embryos. We also began an investigation of the effect of oxidative stress on selenoprotein expression during development. As such, one set of embryos was treated for 24 hours with 100 nM Se-75 and the other with Se-75 plus 200 μM H2O2. In general, we did not observe an overall alteration of selenoprotein expression as a result of SECISBP2L loss. We did, however, observe a significant spike of expression for a 50 kDa selenoprotein that did not occur in the SECISBP2L null animals. Based on this molecular weight, we predict that this band corresponds to selenophosphate synthase (SEPHS2). In addition, subsequent labeling at later time points revealed a general reduction of selenoprotein expression that may result from reduced SEPHS2 expression because it is essential for selenocysteine-tRNA synthesis. Conclusions We conclude that SECISBP2L is required for optimal selenoprotein expression and its function may be induced by oxidative stress. We have also demonstrated the value of a zebrafish model system for studying the mechanism of selenoprotein synthesis. Funding Sources Funded by the National Institutes of Health.

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The control of inflammation via the phosphorylation and dephosphorylation of tristetraprolin: a tale of two phosphatases

Biochemical Society Transactions ◽

10.1042/bst20160166 ◽

2016 ◽

Vol 44 (5) ◽

pp. 1321-1337 ◽

Cited By ~ 39

Author(s):

Andrew R. Clark ◽

Jonathan L.E. Dean

Keyword(s):

Inflammatory Mediators ◽

Knockout Mouse ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Human Orthologue ◽

And Function ◽

Detailed Picture ◽

Lines Of Evidence

Twenty years ago, the first description of a tristetraprolin (TTP) knockout mouse highlighted the fundamental role of TTP in the restraint of inflammation. Since then, work from several groups has generated a detailed picture of the expression and function of TTP. It is a sequence-specific RNA-binding protein that orchestrates the deadenylation and degradation of several mRNAs encoding inflammatory mediators. It is very extensively post-translationally modified, with more than 30 phosphorylations that are supported by at least two independent lines of evidence. The phosphorylation of two particular residues, serines 52 and 178 of mouse TTP (serines 60 and 186 of the human orthologue), has profound effects on the expression, function and localisation of TTP. Here, we discuss the control of TTP biology via its phosphorylation and dephosphorylation, with a particular focus on recent advances and on questions that remain unanswered.

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Faculty Opinions recommendation of The role of interphotoreceptor retinoid-binding protein on the translocation of visual retinoids and function of cone photoreceptors.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1148033.605141 ◽

2009 ◽

Author(s):

Gordon Fain

Keyword(s):

Binding Protein ◽

Cone Photoreceptors ◽

Interphotoreceptor Retinoid Binding Protein ◽

And Function

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NOB1: A Potential Biomarker or Target in Cancer

Current Drug Targets ◽

10.2174/1389450120666190308145346 ◽

2019 ◽

Vol 20 (10) ◽

pp. 1081-1089

Author(s):

Weiwei Ke ◽

Zaiming Lu ◽

Xiangxuan Zhao

Keyword(s):

Cancer Treatment ◽

Molecular Mechanisms ◽

Rna Binding ◽

Binding Protein ◽

Tumor Development ◽

Anticancer Therapy ◽

Research Progress ◽

Normal Tissues ◽

Potential Biomarker

Human NIN1/RPN12 binding protein 1 homolog (NOB1), an RNA binding protein, is expressed ubiquitously in normal tissues such as the lung, liver, and spleen. Its core physiological function is to regulate protease activities and participate in maintaining RNA metabolism and stability. NOB1 is overexpressed in a variety of cancers, including pancreatic cancer, non-small cell lung cancer, ovarian cancer, prostate carcinoma, osteosarcoma, papillary thyroid carcinoma, colorectal cancer, and glioma. Although existing data indicate that NOB1 overexpression is associated with cancer growth, invasion, and poor prognosis, the molecular mechanisms behind these effects and its exact roles remain unclear. Several studies have confirmed that NOB1 is clinically relevant in different cancers, and further research at the molecular level will help evaluate the role of NOB1 in tumors. NOB1 has become an attractive target in anticancer therapy because it is overexpressed in many cancers and mediates different stages of tumor development. Elucidating the role of NOB1 in different signaling pathways as a potential cancer treatment will provide new ideas for existing cancer treatment methods. This review summarizes the research progress made into NOB1 in cancer in the past decade; this information provides valuable clues and theoretical guidance for future anticancer therapy by targeting NOB1.

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The Interplay of RNA Binding Proteins, Oxidative Stress and Mitochondrial Dysfunction in ALS

Antioxidants ◽

10.3390/antiox10040552 ◽

2021 ◽

Vol 10 (4) ◽

pp. 552

Author(s):

Jasmine Harley ◽

Benjamin E. Clarke ◽

Rickie Patani

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Mitochondrial Dysfunction ◽

Binding Proteins ◽

Rna Binding ◽

Rna Binding Proteins ◽

Binding Protein ◽

Rna Binding Protein ◽

Therapeutic Strategies ◽

Lateral Sclerosis

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.

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RBM45 Modulates the Antioxidant Response in Amyotrophic Lateral Sclerosis through Interactions with KEAP1

Molecular and Cellular Biology ◽

10.1128/mcb.00087-15 ◽

2015 ◽

Vol 35 (14) ◽

pp. 2385-2399 ◽

Cited By ~ 12

Author(s):

Nadine Bakkar ◽

Arianna Kousari ◽

Tina Kovalik ◽

Yang Li ◽

Robert Bowser

Keyword(s):

Oxidative Stress ◽

Spinal Cord ◽

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Antioxidant Response ◽

Cytoplasmic Inclusions ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective loss of motor neurons. Various factors contribute to the disease, including RNA binding protein dysregulation and oxidative stress, but their exact role in pathogenic mechanisms remains unclear. We have recently linked another RNA binding protein, RBM45, to ALS via increased levels of protein in the cerebrospinal fluid of ALS patients and its localization to cytoplasmic inclusions in ALS motor neurons. Here we show RBM45 nuclear exit in ALS spinal cord motor neurons compared to controls, a phenotype recapitulatedin vitroin motor neurons treated with oxidative stressors. We find that RBM45 binds and stabilizes KEAP1, the inhibitor of the antioxidant response transcription factor NRF2. ALS lumbar spinal cord lysates similarly show increased cytoplasmic binding of KEAP1 and RBM45. Binding of RBM45 to KEAP1 impedes the protective antioxidant response, thus contributing to oxidative stress-induced cellular toxicity. Our findings thus describe a novel link between a mislocalized RNA binding protein implicated in ALS (RBM45) and dysregulation of the neuroprotective antioxidant response seen in the disease.

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Critical role of tristetraprolin and AU‐rich element RNA‐binding protein 1 in the suppression of cancer cell growth by globular adiponectin

FEBS Open Bio ◽

10.1002/2211-5463.12541 ◽

2018 ◽

Vol 8 (12) ◽

pp. 1964-1976 ◽

Cited By ~ 1

Author(s):

Nirmala Tilija Pun ◽

Amrita Khakurel ◽

Aastha Shrestha ◽

Sang‐Hyun Kim ◽

Pil‐Hoon Park

Keyword(s):

Cell Growth ◽

Cancer Cell ◽

Rna Binding ◽

Binding Protein ◽

Critical Role ◽

Rna Binding Protein ◽

Cancer Cell Growth ◽

Globular Adiponectin

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The Putative RNA-Binding Protein Nrp1 Promotes the Loading of Kinesin-14/Klp2 to the Mitotic Spindle and Is Sequestered Into Heat-Induced Protein Aggregates in Fission Yeast

10.20944/preprints202103.0452.v1 ◽

2021 ◽

Author(s):

Masashi Yukawa ◽

Mitsuki Ohishi ◽

Yusuke Yamada ◽

Takashi Toda

Keyword(s):

Fission Yeast ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Protein Aggregates ◽

Associated Proteins ◽

Spindle Microtubules ◽

The Stability ◽

And Function ◽

Post Transcriptional Regulation

Cells form a bipolar spindle during mitosis to ensure accurate chromosome segregation. Proper spindle architecture is established by a set of kinesin motors and microtubule-associated proteins. In most eukaryotes, kinesin-5 motors are essential for this process, and genetic or chemical inhibition of their activity leads to the emergence of monopolar spindles and cell death. However, these deficiencies can be rescued by simultaneous inactivation of kinesin-14 motors, as they counteract kinesin-5. We conducted detailed genetic analyses in fission yeast to understand the mechanisms driving spindle assembly in the absence of kinesin-5. Here we show that deletion of the nrp1 gene, which encodes a putative RNA-binding protein with unknown function, can rescue temperature sensitivity caused by cut7-22, a fission yeast kinesin-5 mutant. Interestingly, kinesin-14/Klp2 levels on the spindles in the cut7 mutants were significantly reduced by the nrp1 deletion, although the total levels of Klp2 and the stability of spindle microtubules remained unaffected. Moreover, RNA-binding motifs of Nrp1 are essential for its cytoplasmic localization and function. We have also found that a portion of Nrp1 is spatially and functionally sequestered by chaperone-based protein aggregates upon mild heat stress and limits cell division at high temperatures. We propose that Nrp1 might be involved in post-transcriptional regulation through its RNA-binding ability to promote the loading of Klp2 on the spindle microtubules.

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