Autophagic and proteasomal proteolysis are two major pathways for degradation of cellular constituents. Current models suggest that autophagy is responsible for the nonselective bulk degradation of long-lived proteins...Autophagic and proteasomal proteolysis are two major pathways for degradation of cellular constituents. Current models suggest that autophagy is responsible for the nonselective bulk degradation of long-lived proteins and organelles while the proteasome specifically degrades short-lived proteins including misfolded proteins caused by the absence of Hsp90 function. Here, we show that the IκB kinase （IKK）, an essential activator of NF-κB, is selectively degraded by autophagy when Hsp90 is inhibited by geldanamycin （GA）, a specific Hsp90 inhibitor showing highly effective anti-tumor activity. We find that in this case inactivation of ubiquitination or proteasome fails to block IKK degradation. However, inhibition of autophagy by an autophagy inhibitor or knockout of Atg5, a key component of the autophagy pathway, significantly rescues IKK from GA-induced degradation. These findings provide the first evidence that an Hsp90 client may be degraded by a mechanism different from the proteasome pathway and establish a molecular link among Hsp90, NF-κB and autophagy展开更多
Photocatalytic degradation is a promising way to eliminate dye contaminants.In this work,a series of TiO2/ZSM-11(TZ)nanocomposites were prepared using a facile solid state dispersion method.Methyl orange(MO),methylene...Photocatalytic degradation is a promising way to eliminate dye contaminants.In this work,a series of TiO2/ZSM-11(TZ)nanocomposites were prepared using a facile solid state dispersion method.Methyl orange(MO),methylene blue(MB),and rhodamine B(RhB)were intentionally chosen as target substrates in the photocatalytic degradation reactions.Compared to pristine TiO2,negative effect was observed on MO degradation while promoted kinetics were collected on MB and RhB over TZ composites.Moreover,a much higher photocatalytic rate was interestingly achieved on RhB than MB,which indicated that a new factor has to be included other than the widely accepted electrostatic interaction mechanism to fully understand the selective photodegradation reactions.Systematic characterizations showed that TiO2 and ZSM-11 physically mixed and maintained both the whole framework and local structure without chemical interaction.The different trends observed in surface area and the photo-absorption ability of TZ composites with reaction performance further excluded both as the promotion mechanism.Instead,adsorption energies predicted by molecular dynamics simulations suggested that differences in the adsorption strength played a critical role.This work provided a deep mechanistic understanding of the selective photocatalytic degradation of dyes reactions,which helps to rationally design highly efficient photocatalysts.展开更多
Hydrothermal fabrication of selectively doped（Ag＋＋ Pd3＋） advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions（autogeneous; 150°C）.Gluconic acid has been used as a surfa...Hydrothermal fabrication of selectively doped（Ag＋＋ Pd3＋） advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions（autogeneous; 150°C）.Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）, UV–Vis spectroscopy and scanning electron microscopy（SEM）. The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye,Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight.展开更多
文摘Autophagic and proteasomal proteolysis are two major pathways for degradation of cellular constituents. Current models suggest that autophagy is responsible for the nonselective bulk degradation of long-lived proteins and organelles while the proteasome specifically degrades short-lived proteins including misfolded proteins caused by the absence of Hsp90 function. Here, we show that the IκB kinase （IKK）, an essential activator of NF-κB, is selectively degraded by autophagy when Hsp90 is inhibited by geldanamycin （GA）, a specific Hsp90 inhibitor showing highly effective anti-tumor activity. We find that in this case inactivation of ubiquitination or proteasome fails to block IKK degradation. However, inhibition of autophagy by an autophagy inhibitor or knockout of Atg5, a key component of the autophagy pathway, significantly rescues IKK from GA-induced degradation. These findings provide the first evidence that an Hsp90 client may be degraded by a mechanism different from the proteasome pathway and establish a molecular link among Hsp90, NF-κB and autophagy
基金support from the Education Department of Hubei Province through the Science and Technology Research Project(China)(B2021059).
文摘Photocatalytic degradation is a promising way to eliminate dye contaminants.In this work,a series of TiO2/ZSM-11(TZ)nanocomposites were prepared using a facile solid state dispersion method.Methyl orange(MO),methylene blue(MB),and rhodamine B(RhB)were intentionally chosen as target substrates in the photocatalytic degradation reactions.Compared to pristine TiO2,negative effect was observed on MO degradation while promoted kinetics were collected on MB and RhB over TZ composites.Moreover,a much higher photocatalytic rate was interestingly achieved on RhB than MB,which indicated that a new factor has to be included other than the widely accepted electrostatic interaction mechanism to fully understand the selective photodegradation reactions.Systematic characterizations showed that TiO2 and ZSM-11 physically mixed and maintained both the whole framework and local structure without chemical interaction.The different trends observed in surface area and the photo-absorption ability of TZ composites with reaction performance further excluded both as the promotion mechanism.Instead,adsorption energies predicted by molecular dynamics simulations suggested that differences in the adsorption strength played a critical role.This work provided a deep mechanistic understanding of the selective photocatalytic degradation of dyes reactions,which helps to rationally design highly efficient photocatalysts.
基金supported by University Grant Commission under University with Potential for excellence Programme (UPE), University of Mysore
文摘Hydrothermal fabrication of selectively doped（Ag＋＋ Pd3＋） advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions（autogeneous; 150°C）.Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）, UV–Vis spectroscopy and scanning electron microscopy（SEM）. The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye,Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight.
