HP1a Targets the Drosophila KDM4A Demethylase to a Subset of Heterochromatic Genes to Regulate H3K36me3 Levels

The KDM4 subfamily of JmjC domain-containing demethylases mediates demethylation of histone H3K36me3/me2 and H3K9me3/me2. Several studies have shown that human and yeast KDM4 proteins bind to specific gene promoters and regulate gene expression. However, the genome-wide distribution of KDM4 proteins and the mechanism of genomic-targeting remain elusive. We have previously identified Drosophila KDM4A (dKDM4A) as a histone H3K36me3 demethylase that directly interacts with HP1a. Here, we performed H3K36me3 ChIP-chip analysis in wild type and dkdm4a mutant embryos to identify genes regulated by dKDM4A demethylase activity in vivo. A subset of heterochromatic genes that show increased H3K36me3 levels in dkdm4a mutant embryos overlap with HP1a target genes. More importantly, binding to HP1a is required for dKDM4A-mediated H3K36me3 demethylation at a subset of heterochromatic genes. Collectively, these results show that HP1a functions to target the H3K36 demethylase dKDM4A to heterochromatic genes in Drosophila

Quantitative Grafting for Structure–Function Establishment: Thermoresponsive Poly(alkylene oxide) Graft Copolymers Based on Hyaluronic Acid and Carboxymethylcellulose

\ua9 2019 American Chemical Society. A series of thermoresponsive graft copolymers, gelling at physiological conditions in aqueous solution and cell growth media, have been synthesized using quantitative coupling between a small set of amino-functionalized poly(alkylene oxide) copolymers (PAO) and the carboxylate of the biologically important polysaccharides (PSa) carboxymethylcellulose and the less reactive hyaluronate. Quantitative grafting enables the establishment of structure-function relationship which is imperative for controlling the properties of in situ gelling hydrogels. The EDC/NHS-mediated reaction was monitored using SEC-MALLS, which revealed that all PAOs were grafted onto the PSa backbone. Aqueous solutions of the graft copolymers were Newtonian fluids at room temperatures and formed reversible physical gels at elevated temperatures which were noncytotoxic toward chondrocytes. The established structure-function relationship was most clearly demonstrated by inspecting the thermogelling strength and the onset of thermogelling in a phase diagram. The onset of the thermogelling function could be controlled by the global PAO concentration, independent of graft ratio

Replacement of H-bonded bridged water by transition metal ions in poly(1-vinylimidazole-co-methylmethacrylate) copolymers: A vibrational spectroscopy study using mid-FTIR, far-FTIR and ab initio calculations

A detailed structural analysis of the vibrational spectra of hydrophobic PVM (poly(1-vinylimidazole-co-methylmethacrylate)) copolymers PVM-4 (4 wt% 1-VIm) and PVM-44 (44 wt% 1-VIm) is provided with respect to bridging water and subsequent replacement by bridging transition metal ions. PVM-44 (44 wt% 1-VIm) with a high fraction of 1-VIm forms water bridges as evident by the water bending vibration, which is shifted up to 1665 cm(-1). This band vanishes as transition metal ions are introduced and a new band at 952 cm(-1) appears which is ascribed as a delta(ring) band involving the entire [M(Im)(n)](2+) unit. This fact is affirmed using ab initio calculations. The transition metal ions coordinate exclusively the imidazole groups. Although the imidazole associated water is replaced by transition metal ions, the amount of sorbed water for the very hydrophobic PVM-4 is increased as indicated by the nu(OH) region

Replacement of H-bonded bridged water by transition metal ions in poly(1-vinylimidazole-co-methylmethacrylate) copolymers: A vibrational spectroscopy study using mid-FTIR, far-FTIR and ab initio calculations

A detailed structural analysis of the vibrational spectra of hydrophobic PVM (poly(1-vinylimidazole-co-methylmethacrylate)) copolymers PVM-4 (4 wt% 1-VIm) and PVM-44 (44 wt% 1-VIm) is provided with respect to bridging water and subsequent replacement by bridging transition metal ions. PVM-44 (44 wt% 1-VIm) with a high fraction of 1-VIm forms water bridges as evident by the water bending vibration, which is shifted up to 1665 cm(-1). This band vanishes as transition metal ions are introduced and a new band at 952 cm(-1) appears which is ascribed as a delta(ring) band involving the entire [M(Im)(n)](2+) unit. This fact is affirmed using ab initio calculations. The transition metal ions coordinate exclusively the imidazole groups. Although the imidazole associated water is replaced by transition metal ions, the amount of sorbed water for the very hydrophobic PVM-4 is increased as indicated by the nu(OH) region

Role of nanotechnology in the management of indoor fungi

Fungi are ubiquitous in the environment and seek to colonize and grow on diverse materials as part of their life cycle. They constitute complex biofilms on surfaces and deteriorate the indoor air quality even under adverse conditions. They adapt well to changing humidity and temperature conditions, resuming their growth in minutes. Their vital activity generates a large number of pollutants that contribute to bioaerosols, which generate major health problems. The reports published in last few decades pointed out that contaminated environments play an important role in the transmission of infections, especially in hospitals. Advances in the field of nanotechnology have resulted in different and diverse applications. Antimicrobial nanomaterials have been found to be eco‐friendly alternatives to be applied in functional paint and coatings. These ?smart? surfaces could face at nanoscale level the approaching of propagules to avoid their attachment, which is the first stage in biofilm development. In this sense, several nanomaterials, including metal, non‐metal, and hybrids, have been discussed in relation to their antifungal activity in this chapter.Fil: Gámez Espinosa, Erasmo Junior. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Barberia Roque, Leyanet. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Bellotti, Natalia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin