scholarly journals The yeast Cbk1 kinase regulates mRNA localization via the mRNA-binding protein Ssd1

2011 ◽  
Vol 192 (4) ◽  
pp. 583-598 ◽  
Author(s):  
Cornelia Kurischko ◽  
Hong Kyung Kim ◽  
Venkata K. Kuravi ◽  
Juliane Pratzka ◽  
Francis C. Luca
Keyword(s):  
Binding Protein ◽  
Cellular Stress ◽  
Stress Granules ◽  
Polarized Growth ◽  
Cell Integrity ◽  
Processing Bodies ◽  
P Bodies ◽  
Mrna Binding Protein ◽  
Cortical Localization ◽  
Mrna Binding

The mRNA-binding protein Ssd1 is a substrate for the Saccharomyces cerevisiae LATS/NDR orthologue Cbk1, which controls polarized growth, cell separation, and cell integrity. We discovered that most Ssd1 localizes diffusely within the cytoplasm, but some transiently accumulates at sites of polarized growth. Cbk1 inhibition and cellular stress cause Ssd1 to redistribute to mRNA processing bodies (P-bodies) and stress granules, which are known to repress translation. Ssd1 recruitment to P-bodies is independent of mRNA binding and is promoted by the removal of Cbk1 phosphorylation sites. SSD1 deletion severely impairs the asymmetric localization of the Ssd1-associated mRNA, SRL1. Expression of phosphomimetic Ssd1 promotes polarized localization of SRL1 mRNA, whereas phosphorylation-deficient Ssd1 causes constitutive localization of SRL1 mRNA to P-bodies and causes cellular lysis. These data support the model that Cbk1-mediated phosphorylation of Ssd1 promotes the cortical localization of Ssd1–mRNA complexes, whereas Cbk1 inhibition, cellular stress, and Ssd1 dephosphorylation promote Ssd1–mRNA interactions with P-bodies and stress granules, leading to translational repression.

scholarly journals Poly(A)+mRNA-binding protein Tudor-SN regulates stress granules aggregation dynamics

FEBS Journal ◽  
2015 ◽  
Vol 282 (5) ◽  
pp. 874-890 ◽  
Author(s):  
Xingjie Gao ◽  
Xue Fu ◽  
Juan Song ◽  
Yi Zhang ◽  
Xiaoteng Cui ◽  
...  
Keyword(s):  
Binding Protein ◽  
Stress Granules ◽  
Mrna Binding Protein ◽  
Mrna Binding

scholarly journals Hypoxia up-regulates the activity of a novel erythropoietin mRNA binding protein.

1991 ◽  
Vol 266 (25) ◽  
pp. 16594-16598
Author(s):  
I.J. Rondon ◽  
L.A. MacMillan ◽  
B.S. Beckman ◽  
M.A. Goldberg ◽  
T. Schneider ◽  
...  
Keyword(s):  
Binding Protein ◽  
Mrna Binding Protein ◽  
Mrna Binding

Abstract 191: Ras GTPase-activating Protein SH3 Domain Binding Protein 1 (G3BP1) Regulates The Induction Of Stress Granules During Cardiac Hypertrophy

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Danish Sayed
Keyword(s):  
Cardiac Hypertrophy ◽  
Cardiac Myocytes ◽  
Posttranscriptional Regulation ◽  
Binding Protein ◽  
Stress Granules ◽  
Sh3 Domain ◽  
Gtpase Activating Protein ◽  
Ras Gtpase ◽  
Mrna Binding

Stress granules (SGs) are dynamic, microscopically visible, cytoplasmic bodies that play a major role in mRNA metabolism (e.g. sorting, storage, decay) and induced in cells during stress conditions like starvation, oxidative strain or growth. With substantial role in cancer and neurodegenerative diseases, these granules have never been studied during cardiac hypertrophy, or in the heart in general. Several studies have identified independent proteins, mostly mRNA binding proteins that are part of these granules, some of which are sufficient to nucleate the assembly in quiescent cells even without stress. One such mRNA binding protein is Ras GTPase-activating protein SH3 domain binding protein 1 (G3BP1), which increases during cardiac hypertrophy via posttranscriptional regulation. Thus, we hypothesized that G3BP1 might be involved in the induction of SGs during hypertrophy and hence in regulating mRNA processing and gene expression. Our aim was to investigate, 1) if these SGs appear in hypertrophied hearts and 2) if G3BP1 is necessary and sufficient to induce them during hypertrophic stimuli. In vivo staining of TIA-1/TIAR (SG marker) in mouse hearts subjected to sham or transaortic coarctation (TAC) surgeries showed accumulation of these granules with cardiac hypertrophy. Similar induction was seen in isolated, cultured, rat neonatal cardiac myocytes with hypertrophic stimulation (Endothelin1) or overexpression of G3BP1 alone (>60% of myocytes stained for SG). Conversely, switch to growth-inhibited conditions or knockdown of G3BP1 in hypertrophying myocytes was sufficient to prevent the assembly of these structures. Co-staining with other components of these granules like TIA-1/TIAR or proteins specific to P bodies, like decapping enzyme 1 validated these structures as SGs in cardiac myocytes. Interestingly, a long non-coding RNA, Gas5 (Growth Arrest Specific 5) that is validated binding partner of G3BP1 sequestered to perinuclear focal locations in myocytes stimulated with ET1, suggesting growth-induced recruitment to SGs. While we are still in process of examining G3BP1 targets that are recruited to SGs and their role in hypertrophy development, we have concluded that G3BP1 is required for the induction of SGs during cardiac hypertrophy

Increased expression of the MBP mRNA binding protein HnRNP A2 during oligodendrocyte differentiation

2004 ◽  
Vol 75 (5) ◽  
pp. 614-623 ◽  
Author(s):  
M. Maggipinto ◽  
C. Rabiner ◽  
G.J. Kidd ◽  
A.J. Hawkins ◽  
R. Smith ◽  
...  
Keyword(s):  
Binding Protein ◽  
Oligodendrocyte Differentiation ◽  
Mrna Binding Protein ◽  
Mrna Binding

scholarly journals Human Insulin Growth Factor 2 mRNA Binding Protein 2 Increases MicroRNA 33a/b Inhibition of Liver ABCA1 Expression and Alters Low-Density Apolipoprotein Levels in Mice

2020 ◽  
Vol 40 (16) ◽  
Author(s):  
Muhua Yang ◽  
Christina Gallo-Ebert ◽  
Michael Hayward ◽  
Weidong Liu ◽  
Virginia McDonough ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Association Studies ◽  
Blood Levels ◽  
Genome Wide Association Studies ◽  
Low Density ◽  
Nucleotide Polymorphisms ◽  
Insulin Growth Factor ◽  
Mrna Binding Protein ◽  
Mrna Binding

ABSTRACT Genome-wide association studies (GWAS) have linked IGF2BP2 single-nucleotide polymorphisms (SNPs) with type 2 diabetes (T2D). Mice overexpressing mIGF2BP2 have elevated cholesterol levels when fed a diet that induces hepatic steatosis. These and other studies suggest an important role for insulin growth factor 2 mRNA binding protein 2 (IGF2BP2) in the initiation and progression of several metabolic disorders. The ATPase binding cassette protein ABCA1 initiates nascent high-density apolipoprotein (HDL) biogenesis by transferring phospholipid and cholesterol to delipidated apolipoprotein AI (ApoAI). Individuals with mutational ablation of ABCA1 have Tangier disease, which is characterized by a complete loss of HDL. MicroRNA 33a and 33b (miR-33a/b) bind to the 3′ untranslated region (UTR) of ABCA1 and repress its posttranscriptional gene expression. Here, we show that IGF2BP2 works together with miR-33a/b in repressing ABCA1 expression. Our data suggest that IGF2BP2 is an accessory protein of the argonaute (AGO2)–miR-33a/b–RISC complex, as it directly binds to miR-33a/b, AGO2, and the 3′ UTR of ABCA1. Finally, we show that mice overexpressing human IGF2BP2 have decreased ABCA1 expression, increased low-density lipoprotein-cholesterol (LDL-C) and cholesterol blood levels, and elevated SREBP-dependent signaling. Our data support the hypothesis that IGF2BP2 has an important role in maintaining lipid homeostasis through its modulation of ABCA1 expression, as its overexpression or loss leads to dyslipidemia.

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