scholarly journals Fructose modulates GLUT5 mRNA stability in differentiated Caco-2 cells: role of cAMP-signalling pathway and PABP (polyadenylated-binding protein)-interacting protein (Paip) 2

2003 ◽  
Vol 375 (1) ◽  
pp. 167-174 ◽  
Author(s):  
Florence GOUYON ◽  
Cercina ONESTO ◽  
Veronique DALET ◽  
Gilles PAGES ◽  
Armelle LETURQUE ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Protein Complexes ◽  
Binding Protein ◽  
Interacting Protein ◽  
Camp Signalling ◽  
Camp Pathway ◽  
Post Transcriptional Regulation ◽  
Rna Protein Complexes ◽  
Camp Levels

In intestinal cells, levels of the fructose transporter GLUT5 are increased by glucose and to a greater extent by fructose. We investigated the mechanism by which fructose increases GLUT5 expression. In Caco-2 cells, fructose and glucose increased activity of the −2500/+41 GLUT5 promoter to the same extent. cAMP also activated the GLUT5 promoter. However, if a protein kinase A inhibitor was used to block cAMP signalling, extensive GLUT5 mRNA degradation was observed, with no change in basal transcription levels demonstrating the involvement of cAMP in GLUT5 mRNA stability. Indeed, the half-life of GLUT5 mRNA was correlated (R2=0.9913) with cellular cAMP levels. Fructose increased cAMP concentration more than glucose, accounting for the stronger effect of fructose when compared with that of glucose on GLUT5 production. We identified several complexes between GLUT5 3′-UTR RNA (where UTR stands for untranslated region) and cytosolic proteins that might participate in mRNA processing. Strong binding of a 140 kDa complex I was observed in sugar-deprived cells, with levels of binding lower in the presence of fructose and glucose by factors of 12 and 6 respectively. This may account for differences in the effects of fructose and glucose. In contrast, the amounts of two complexes of 96 and 48 kDa increased equally after stimulation with either glucose or fructose. Finally, PABP (polyadenylated-binding protein)-interacting protein 2, a destabilizing partner of PABP, was identified as a component of GLUT5 3′-UTR RNA–protein complexes. We conclude that the post-transcriptional regulation of GLUT5 by fructose involves increases in mRNA stability mediated by the cAMP pathway and Paip2 (PABP-interacting protein 2) binding.

scholarly journals Loss of PABPC1 is compensated by elevated PABPC4 and correlates with transcriptome changes

2021 ◽  
Author(s):  
Jingwei Xie ◽  
Xiaoyu Wei ◽  
Yu Chen
Keyword(s):  
Genome Editing ◽  
Transcriptome Analysis ◽  
Mrna Stability ◽  
Binding Protein ◽  
Transcriptional Regulators ◽  
Hek293 Cells ◽  
Translation Factor ◽  
Development And Differentiation ◽  
Insight Into

AbstractCytoplasmic poly(A) binding protein (PABP) is an essential translation factor that binds to the 3’ tail of mRNAs to promote translation and regulate mRNA stability. PABPC1 is the most abundant of several PABP isoforms that exist in mammals. Here, we used the CRISPR/Cas genome editing system to shift the isoform composition in HEK293 cells. Disruption of PABPC1 elevated PABPC4 levels. Transcriptome analysis revealed that the shift in the dominant PABP isoform was correlated with changes in key transcriptional regulators. This study provides insight into understanding the role of PABP isoforms in development and differentiation.

scholarly journals Granule regulation by phase separation during Drosophila oogenesis

2020 ◽  
Vol 4 (3) ◽  
pp. 355-364
Author(s):  
M. Sankaranarayanan ◽  
Timothy T. Weil
Keyword(s):  
Phase Separation ◽  
Translational Control ◽  
Protein Complexes ◽  
Physiological Role ◽  
Drosophila Oogenesis ◽  
And Function ◽  
Rna Protein Complexes ◽  
Liquid Liquid Phase Separation

Drosophila eggs are highly polarised cells that use RNA–protein complexes to regulate storage and translational control of maternal RNAs. Ribonucleoprotein granules are a class of biological condensates that form predominantly by intracellular phase separation. Despite extensive in vitro studies testing the physical principles regulating condensates, how phase separation translates to biological function remains largely unanswered. In this perspective, we discuss granules in Drosophila oogenesis as a model system for investigating the physiological role of phase separation. We review key maternal granules and their properties while highlighting ribonucleoprotein phase separation behaviours observed during development. Finally, we discuss how concepts and models from liquid–liquid phase separation could be used to test mechanisms underlying granule assembly, regulation and function in Drosophila oogenesis.

scholarly journals Identification of complexes between the tyrosine-O-sulphate-binding protein and tyrosine-sulphated proteins in bovine liver membrane lysates

1991 ◽  
Vol 275 (1) ◽  
pp. 259-262 ◽  
Author(s):  
M C Liu ◽  
R L Lu ◽  
J R Han ◽  
X B Tang ◽  
M Suiko ◽  
...  
Keyword(s):  
Protein Complexes ◽  
Binding Protein ◽  
Rabbit Antiserum ◽  
Bovine Liver ◽  
Liver Membrane ◽  
Covalently Bonded ◽  
Co Precipitation

Rabbit antiserum against electrophoretically purified bovine liver tyrosine-O-sulphate (TyrS)-binding protein was prepared. Affinity-purified antibodies from the antiserum were found to be capable of immunoprecipitating the TyrS-binding protein from the sodium choleate extract of a bovine liver microsomal membrane fraction. Using purified specific antibodies as the probe, Western blot analysis for the presence of TyrS-binding protein/tyrosine-sulphated protein complexes in bovine liver membrane lysates was performed. It was found that the TyrS-binding protein co-precipitated with three tyrosine-sulphated proteins (fibronectin, fibrinogen and complement C4) immunoprecipitated by their respective antibodies. In contrast, for the two non-tyrosine-sulphated proteins (haptoglobin and transferrin) tested, co-precipitation of the TyrS-binding protein was not observed. On employing an affinity gel fractionation technique, it was shown that partially purified TyrS-binding protein exhibited binding affinity towards Sepharose gels covalently bonded to fibronectin or fibrinogen, but not towards Sepharose gels bonded to albumin or transferrin. These results indicate that the TyrS-binding protein formed complexes with tyrosine-sulphated proteins both in vivo and in vitro, and thus provide support for the putative role of the former being the receptor of the latter.

scholarly journals The role of Ran-binding protein 3 during influenza A virus replication

2013 ◽  
Vol 94 (5) ◽  
pp. 977-984 ◽  
Author(s):  
Rey Predicala ◽  
Yan Zhou
Keyword(s):  
Life Cycle ◽  
Influenza A Virus ◽  
Nuclear Export ◽  
Influenza A ◽  
Binding Protein ◽  
Late Phase ◽  
Nuclear Retention ◽  
Interacting Protein ◽  
Virus Life Cycle

Influenza A virus vRNP nuclear export is CRM1-dependent. Ran-binding protein 3 (RanBP3) is a Ran-interacting protein that is best known for its role as a cofactor of CRM1-mediated cargo nuclear export. In this study, we investigated the role of RanBP3 during the influenza A virus life cycle. We found that RanBP3 was phosphorylated at Ser58 in the early and late phases of infection. Knockdown of RanBP3 expression led to vRNP nuclear retention, suggesting that RanBP3 is involved in vRNP nuclear export. Moreover, we demonstrated that the function of RanBP3 during vRNP nuclear export is regulated by phosphorylation at Ser58, and that RanBP3 phosphorylation is modulated by both PI3K/Akt and Ras/ERK/RSK pathways in the late phase of viral infection.

scholarly journals HuR Regulates p21 mRNA Stabilization by UV Light

2000 ◽  
Vol 20 (3) ◽  
pp. 760-769 ◽  
Author(s):  
Wengong Wang ◽  
Henry Furneaux ◽  
Huiming Cheng ◽  
M. Craig Caldwell ◽  
Dorothy Hutter ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Rna Binding ◽  
Kinase Inhibitor ◽  
Uv Light ◽  
Protein Complexes ◽  
Cyclin Dependent Kinase ◽  
Western Blots ◽  
Mrna Stabilization ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Rna Protein Complexes

ABSTRACT Expression of the cyclin-dependent kinase inhibitor p21 is highly induced by many stresses, including exposure to short-wavelength UV light (UVC), which increases p21 mRNA stability. Investigation into the mechanisms underlying this stabilization process revealed that proteins present in cytoplasmic lysates of human RKO colorectal carcinoma cells formed complexes with p21 mRNA that were inducible by treatment with UVC and other stress agents. The ubiquitous Elav-type RNA-binding protein HuR was identified within the p21 mRNA-protein complexes, as antibodies recognizing HuR supershifted these complexes and revealed HuR-immunoreactive proteins complexing with p21 mRNA on Western blots. Lowering of endogenous HuR levels through expression of antisense HuR decreased p21 RNA-protein complexes, greatly reduced the UVC inducibility and half-life of p21 mRNA, and prevented UVC-mediated induction of luciferase activity in p21 3′ untranslated region-containing reporter constructs. Our findings indicate that HuR plays a major role in regulating stress-induced p21 expression by enhancing p21 mRNA stability and that these effects are coupled to HuR's elevated presence in the cytoplasm.

scholarly journals Base-intercalated and base-wedged stacking elements in 3D-structure of RNA and RNA–protein complexes

2020 ◽  
Vol 48 (15) ◽  
pp. 8675-8685
Author(s):  
Eugene Baulin ◽  
Valeriy Metelev ◽  
Alexey Bogdanov
Keyword(s):  
Tertiary Structure ◽  
Protein Complexes ◽  
3D Structure ◽  
Data Bank ◽  
Rna Structures ◽  
Tertiary Structures ◽  
Long Range Interactions ◽  
Heterocyclic Bases ◽  
Rna Protein Complexes

Abstract Along with nucleobase pairing, base-base stacking interactions are one of the two main types of strong non-covalent interactions that define the unique secondary and tertiary structure of RNA. In this paper we studied two subfamilies of nucleobase-inserted stacking structures: (i) with any base intercalated between neighboring nucleotide residues (base-intercalated element, BIE, i + 1); (ii) with any base wedged into a hydrophobic cavity formed by heterocyclic bases of two nucleotides which are one nucleotide apart in sequence (base-wedged element, BWE, i + 2). We have exploited the growing database of natively folded RNA structures in Protein Data Bank to analyze the distribution and structural role of these motifs in RNA. We found that these structural elements initially found in yeast tRNAPhe are quite widespread among the tertiary structures of various RNAs. These motifs perform diverse roles in RNA 3D structure formation and its maintenance. They contribute to the folding of RNA bulges and loops and participate in long-range interactions of single-stranded stretches within RNA macromolecules. Furthermore, both base-intercalated and base-wedged motifs participate directly or indirectly in the formation of RNA functional centers, which interact with various ligands, antibiotics and proteins.

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