The DEAD-box RNA helicase DDX3X is a multifunctional protein involved in RNA metabolism and stress responses. In this study, we investigated the role of RG/RGG motifs in the dynamic process of liquid-liquid phase separation (LLPS) of DDX3X using cell-free assays and explored their potential link to cancer development through bioinformatic analysis. Our results demonstrate that the number, location, and composition of RG/RGG motifs significantly influence the ability of DDX3X to undergo phase separation and form self-aggregates. Mutational analysis revealed that the spacing between RG/RGG motifs and the number of glycine residues within each motif are critical factors in determining the extent of phase separation. Bioinformatic analysis of cancer genomic datasets uncovered a significant enrichment of DDX3X mutations in RG/RGG motifs across multiple cancer types, particularly in the N-terminal region of the protein. Furthermore, we found that DDX3X is co-expressed with the stress granule protein G3BP1 in several cancer types and can undergo co-phase separation with G3BP1 in a cell-free system, suggesting a potential functional interaction between these proteins in phase-separated structures. DDX3X and G3BP1 may interact through their RG/RGG domains and subsequently exert important cellular functions under stress situation. Collectively, our findings provide novel insights into the role of RG/RGG motifs in modulating DDX3X phase separation and their potential contribution to cancer pathogenesis.

The fine structure of Apricot pectin polysaccharides is discussed from both literature and recent work we have performed. Structural characterization utilized 1D and 2D homo- and hetero-nuclear NMR spectroscopy including results from High Performance Size Exclusion Chromatography (HP-SEC), HP Anion-Exchange Chromatography with Pulsed Amperometric Detection (HPAEC-PAD) and FTIR spectroscopy. The purified pectin fraction (F1AP) was found to be composed of D-galacturonic acid, L-rhamnose, D-arabinose and D-galactose in a 1.0 : 0.1 : 0.36 : 0.12 molar ratio, respectively, which is consistent with a pectin RG-1 branched with arabinogalactan side chain polysaccharides, and has a weight-average molecular weight of approximately 1588.2 kDa. The slope of the hydrodynamic radius versus the molar mass was 0.57, indicating the presence of coil conformations. The results from HPAEC-PAD, HPSEC and NMR spectroscopy (1H, 13C, zTOCSY, HSQC, HSQCTOXY and HMBC) demonstrated that F1AP fine fraction F1AP1, derived from original F1AP, has a backbone of (1→4)-linked -D-galacturonic acid and -L-rhamnopyranosyl residues branched with arabinogalactan of multiply glycosidic linkages of T- α-Araf, 3-α-Araf, 5-α-Araf, T- α -Arap, 2- α-Arap side chains, having methyl and acetylated groups, and has high molecular weights (1945 kDa). While the other F1A6 fraction consists predominately of an HG region of pectin polysaccharides with low molecular weights (117.5 kDa), less aggregated. The F1AP1 polysaccharide was highly viscous and its hydrodynamic radius was 64,3 nm. The exponent b of Rh-Mw (conformation plot) was determined to be 0.48, indicating a compact flexible coil conformation of the macromolecule in solution. However, the F1AP6 fraction of apricot fruits belong to backbone of repeats units of [-(1→4)-α-D-GalpA-1]n – both HG and partly contents RG-II polysaccharides, bearing heterosugar sidechains, including α-Ara, α -Rha and β-Gal residues and adopt more stiffness rod like conformation.

Most authors have investigated the role of mannoproteins on wine quality but very few analyze the use of grape derived polysaccharides as they are not commercially available. Purified grape derived polysaccharides from red wine (WPP) and winemaking by-products (DWRP: Distilled Washing Residues Polysaccharides) were used as potential fining agents to modulate white wine flavour. Phenolics and volatile compounds were analyzed in control and wines treated with WPP, DWRP and commercial mannoproteins (CM) after one and twelve months of bottling, and a sensory analysis was conducted. WPP and DWRP, rich in rhamnogalacturonans-II, showed as good modulators of wine aroma and astringency. Improvement of wine aroma was related to an increase of all volatile families expect higher alcohols and volatile acids. The modulation of astringency and bitterness was related to a reduction in the proanthocyanidin content and its mean degree of polymerization. Extracts with polysaccharides with higher protein contents presented higher retention of volatile compounds, and DWRP extract showed more positive effects on the overall aroma. Our novel results open the possibility of obtaining valuable polysaccharides from distilled washing residues of wine-pomaces, which could promote its valorization as by-product. This is the first time to describe the potential use of this by-product.

This paper explores the Wilsonian renormalization group of probe-D-branes, focusing on the Dirac-Born-Infeld (DBI) action. The analysis involves deriving the constant of motion and formulating the Wilsonian renormalization group equation. The study extends to the infrared regime, considering both zero and non-zero temperatures. Additionally, thermodynamic aspects related to the functional form of the grand potential are discussed. The investigation provides insights into the renormalization of probe-D-branes and their thermodynamic properties.