Autophagy Inhibitor LRPPRC Suppresses Mitophagy through Interaction with Mitophagy Initiator Parkin

Autophagy plays an important role in tumorigenesis. Mitochondrion-associated protein LRPPRC interacts with MAP1S that interacts with LC3 and bridges autophagy components with microtubules and mitochondria to affect autophagy flux. Dysfunction of LRPPRC and MAP1S is associated with poor survival of ovarian cancer patients. Furthermore, elevated levels of LRPPRC predict shorter overall survival in patients with prostate adenocarcinomas or gastric cancer. To understand the role of LRPPRC in tumor development, previously we reported that LRPPRC forms a ternary complex with Beclin 1 and Bcl-2 to inhibit autophagy. Here we further show that LRPPRC maintains the stability of Parkin that mono-ubiquitinates Bcl-2 to increase Bcl-2 stability to inhibit autophagy. Under mitophagy stress, Parkin translocates to mitochondria to cause rupture of outer mitochondrial membrane and bind with exposed LRPPRC. Consequently, LRPPRC and Parkin help mitochondria being engulfed in autophagosomes to be degraded. In cells under long-term mitophagy stress, both LRPPRC and Parkin become depleted coincident with disappearance of mitochondria and final autophagy inactivation due to depletion of ATG5-ATG12 conjugates. LRPPRC functions as a checkpoint protein that prevents mitochondria from autophagy degradation and impact tumorigenesis

Comparison of fruit morphology and nutrition metabolism in different cultivars of kiwifruit across developmental stages

Kiwifruit (Actinidia) is becoming increasingly popular worldwide due to its favorable flavour and high vitamin C content. However, quality parameters vary among cultivars. To determine the differences in quality and metabolic parameters of kiwifruit, we monitored the growth processes of ‘Kuilv’ (Actinidia arguta), ‘Hongyang’ (Actinidia chinensis) and ‘Hayward’ (Actinidia deliciosa). We found that ‘Kuilv’ required the shortest time for fruit development, while ‘Hayward’ needed the longest time to mature. The fruit size of ‘Hayward’ was the largest and that of ‘Kuilv’ was the smallest. Furthermore, ‘Hongyang’ showed a double-S shape of dry matter accumulation, whereas ‘Kuilv’ and ‘Hayward’ showed a linear or single-S shape pattern of dry matter accumulation during development. The three cultivars demonstrated the same trend for total soluble solids accumulation, which did not rise rapidly until 90–120 days after anthesis. However, the accumulation of organic acids and soluble sugars varied among the cultivars. During later fruit development, the content of glucose, fructose and quinic acid in ‘Kuilv’ fruit was far lower than that in ‘Hongyang’ and ‘Hayward’. On the contrary, ‘Kuilv’ had the highest sucrose content among the three cultivars. At maturity, the antioxidative enzymatic systems were significantly different among the three kiwifruit cultivars. ‘Hongyang’ showed higher activities of superoxide dismutase than the other cultivars, while the catalase content of ‘Hayward’ was significantly higher than that of ‘Hongyang’ and ‘Kuilv’. These results provided knowledge that could be implemented for the marketing, handling and post-harvest technologies of the different kiwifruit cultivars

Preparation and characterization of steel slag-based low, medium, and high-temperature composite phase change energy storage materials

In this study, industrial solid waste steel slag was used as supporting material for the first time, and polyethylene glycol (PEG), sodium nitrate (NaNO3), and sodium sulfate (Na2SO4) were used as low, medium, and high -temperature phase change materials (PCMs). A series of shape-stable composite phase change materials (C-PCMs) were prepared by vacuum impregnation and mixing-sintering methods. The morphology, thermal prop-erties, and thermal reliability of C-PCMs were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). The results show that the three PCMs are uniformly dispersed in the pores of steel slag, and the maximum loading is 35 %, 40 %, and 50 %, respectively, and they have good chemical compatibility with steel slag. Compared with their pure PCMs, the three prepared C-PCMs showed a reduction in subcooling of 2.64 degrees C, 4.53 degrees C and 0.79 degrees C, respectively, and an increase in thermal conductivity of 172 %, 54.9 % and 82.4 %, respectively, all with good phase change thermal storage properties. Even after 100 thermal cycles, the latent heat retention rate was more than 97 %, which had good thermal reliability. Therefore, it can be concluded that the three kinds of low, medium, and high -temperature C-PCMs have considerable application potential in different temperature areas, such as building latent heat storage, solar energy storage systems, and industrial waste heat recovery system

The Effects of COVID-19 Lockdown on Air Pollutant Concentrations across China: A Google Earth Engine-Based Analysis

To overcome the spread of the severe COVID-19 outbreak, various lockdown measures have been taken worldwide. China imposed the strictest home-quarantine measures during the COVID-19 outbreak in the year 2020. This provides a valuable opportunity to study the impact of anthropogenic emission reductions on air quality. Based on the GEE platform and satellite imagery, this study analyzed the changes in the concentrations of NO2, O3, CO, and SO2 in the same season (1 February–1 May) before and after the epidemic control (2019–2021) for 16 typical representative cities of China. The results showed that NO2 concentrations significantly decreased by around 20–24% for different types of metropolises, whereas O3 increased for most of the studied metropolises, including approximately 7% in megacities and other major cities. Additionally, the concentrations of CO and SO2 showed no statistically significant changes during the study intervals. The study also indicated strong variations in air pollutants among different geographic regions. In addition to the methods in this study, it is essential to include the differences in meteorological impact factors in the study to identify future references for air pollution reduction measures

Cloning and characterization of the yak gene coding for calpastatin and in silico analysis of its putative product

The calcium-activated neutral proteases, μ- and m-calpain, along with their inhibitor, calpastatin, have been demonstrated to mediate a variety of Ca2+-dependent processes including signal transduction, cell proliferation, cell cycle progression, differentiation, apoptosis, membrane fusion, platelet activation and skeletal muscle protein degradation. The cDNA coding for yak calpastatin was amplified and cloned by RT-PCR to investigate and characterize the nucleotide/amino-acid sequence and to predict structure and function of the calpastatin. The present study suggests that the yak calpastatin gene encodes a protein of 786 amino acids that shares 99 % sequence identity with the amino-acid sequence of cattle calpastatin, and that the yak protein is composed of an N-terminal region (domains L and XL) and four repetitive homologous C-terminal domains (d1–d4), in which several prosite motifs are present including short peptide L54–64 (EVKPKEHTEPK in domain L) and GXXE/ DXTIPPXYR (in subdomain B), where X is a variable amino acid. Our results suggest the existence of other functional sites including potential phosphorylation sites for protein kinase C, cAMP- and cGMP-dependent protein kinase, casein kinase II, as well as N-myristoylation and amidation sites that play an important role in molecular regulation of the calpain/calpastatin system. The regulation of the calpain/calpastatin system is determined by the interaction between dIV and dVI in calpains and subdomains A, B, and C in calpastatin

Preparation and characterization of steel slag-based low, medium, and high-temperature composite phase change energy storage materials

In this study, industrial solid waste steel slag was used as supporting material for the first time, and polyethylene glycol (PEG), sodium nitrate (NaNO3), and sodium sulfate (Na2SO4) were used as low, medium, and high -temperature phase change materials (PCMs). A series of shape-stable composite phase change materials (C-PCMs) were prepared by vacuum impregnation and mixing-sintering methods. The morphology, thermal prop-erties, and thermal reliability of C-PCMs were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). The results show that the three PCMs are uniformly dispersed in the pores of steel slag, and the maximum loading is 35 %, 40 %, and 50 %, respectively, and they have good chemical compatibility with steel slag. Compared with their pure PCMs, the three prepared C-PCMs showed a reduction in subcooling of 2.64 degrees C, 4.53 degrees C and 0.79 degrees C, respectively, and an increase in thermal conductivity of 172 %, 54.9 % and 82.4 %, respectively, all with good phase change thermal storage properties. Even after 100 thermal cycles, the latent heat retention rate was more than 97 %, which had good thermal reliability. Therefore, it can be concluded that the three kinds of low, medium, and high -temperature C-PCMs have considerable application potential in different temperature areas, such as building latent heat storage, solar energy storage systems, and industrial waste heat recovery system

An innovative artificial photosystem II constructed from PSII core of Thermosynechococcus vulcanus and LHCII of Pisum sativum - A new approach for studying the function of photosynthetic antenna

In photosynthesis, the antenna system captures solar energy and transfers the excitations to photosystem II (PSII) core complex where charge separation, water splitting and oxygen evolution occur. In the evolution of photosynthesis from aquatic to terrestrial environments, the structure of PSII core complex was highly conserved while a variety of antenna forms became differentiated. In order to study the principles for energy transport from antenna to the PSII reaction center, we have explored whether the major light harvesting complex of PSII (LHCII) of higher plants can transfer energy to the cyanobacteria PSII core complexes (CC). For this purpose, LHCII from pea and CC from Thermosynechococcus vulcanus were isolated and co-reconstituted into liposome at LHCII:CC molar ratios of 2:1, 4:1 and 6:1, respectively. Chemical-cross linking followed by LC-MS/MS analysis confirmed the biochemical interaction between LHCII and CC in the liposome membrane. The analyses of 77 K fluorescence emission spectra and antenna cross section of PSII indicated that LHCII can transfer energy directly to the cyanobacterial CC. The study has laid the basis for further research on the mechanism of energy transfer from LHCII to PSII CC. This result may also open a new possibility for design and development of new artificial PSII in the application of solar energy conversion

Electrostatic adsorption of a fluorophores-modified light-harvesting complex II on TiO2 photoanodes enhances photovoltaic performance

The major light-harvesting complex of photosystem II, or LHCII, has been utilized in photovoltaic applications because of its high pigment density. In vitro assembled recombinant LHCII is a modifiable biomimetic material for solar energy conversion. In this report, we assemble a modified recombinant LHCII from apoproteins covalently conjugated artificial fluorophores Atto 590 which absorb greatly near visible green region, where LHCII possesses relatively weak absorption. The absorption and fluorescence excitation spectra indicate that the modified recombinant LHCII possesses enhanced light harvesting capacity because Atto 590 molecules efficiently transfer energy to LHCII. The unmodified or modified recombinant LHCII is then adsorbed on the TiO2 electrode respectively to construct sensitized solar cells, both of which present remarkable photovoltaic enhancement. The incident photon-to-electron conversion efficiency measurements confirm the contribution of the artificial fluorophores. The modified recombinant LHCII sensitized solar cell presents 9.1% increase in open circuit voltage and 13.6% increase in short-circuit current density, compared to the unmodified one. These results suggest that modifications of the recombinant LHCII are feasible ways to enhance its performance in biophotovoltaic cells