Structures and Functions of Cuticular Wax in Postharvest Fruit and Its Regulation:A Comprehensive Review with Future Perspectives

Cuticular wax plays a major role in the growth and storage of plant fruits.The cuticular wax coating,which covers the outermost layer of a fruit’s epidermal cells,is insoluble in water.Cuticular wax is mainly composed of very long-chain fatty acids(VLCFAs);their derivatives,including esters,primary alcohols,secondary alcohols,aldehydes,and ketones;and triterpenoids.This complex mixture of lipids is probably biosynthesized in the epidermal cells of most plants and exuded onto the surface.Cuticular wax not only makes the fruit less susceptible to microbial infection but also reduces mechanical damage to the fruit,thereby maintaining the fruit’s commodity value.To date,research has mostly focused on the changes,function,and regulation of fruit wax before harvest,while ignoring the changes and functions of wax in fruit storage.This paper reviews on the composition,structure,and metabolic regulation of cuticular wax in fruits.It also focuses on postharvest factors affecting wax composition,such as storage temperature,relative humidity(RH),gas atmosphere,and as exogenous hormones;and the effects of wax on fruit postharvest quality,including water dispersion,fruit softening,physiological disorders,and disease resistance.These summaries may be of assistance in better understanding the changes in cuticular wax in postharvest fruit and the resulting effects on fruit quality.

Effects of Aluminum Trichloride on Structure and Function of Kidney in Chickens

To investigate the effects of aluminum trichloride （AlCl3） on renal structure and function in chickens, the chickens were injected continuously with different gradient AlCl3 for 60 days to establish sub-chronic aluminum （Al） intoxication model. The AI concentration in serum and kidney, contents of creatinine （Cr） and blood urea nitrogen （BUN） in serum were detected, and the renal structure was also observed by optical microscope. The results showed that the A1 concentration in serum and kidney, the contents of Cr and BUN in serum were significantly higher in Al-treated chickens than those in the control group （P〈0.05; P〈0.01） and there was an AlCl3 dose-depended manner. Histopathologically, in the low dose group, acinus renis swelled mildly and there were no apparent pathological changes in nephric tubule and proximal convoluted tubule. In the middle and high dose group, acinus renis swelled, glomerular cells increased, nephric tubule cloudy swelled, and epithelial cells of proximal convoluted tubule swelled. The results indicated that sub-chronic Al exposure impaired the renal structure and function in chickens.

Co-regulator NCOA5 and cancer

NCOA5 encodes a co-regulator for estrogen receptors(ERαand ERβ),orphan nuclear receptors(REV-ERBαand REV-ERBβ)and liver X receptor.It can influence many cellular processes by either promoting or inhibiting gene expression through its two important functional motifs:LxxLL(co-activator)andΦxxΦΦ(co-repressor).Many reports have revealed the important roles of NCOA5 in diseases,such as diabetes,reproductive defects and autoimmune disease.In this review,we focus on its function in cancers and summary the current research progresses regarding its different roles in various cancers.

Both structure and function of human monoclonal antibodies contribute to enhancement of Zika virus infectivity in vitro

Dear Editor,Antibody-dependent enhancement（ADE）has long been recognized for dengue virus（DENV）in vitro and in vivo.It is now clear that antibodies to DENV can also enhance Zika virus（ZIKV）infection in vitro,and vice versa（Dejnirattisai et al.,2016;Stettler et al.,2016）.The characteristics of enhancing antibodies,however,remain elusive.

Emerging approaches to probing ion channel structure and function

Ion channels,as membrane proteins,are the sensors of the cell.They act as the first line of communication with the world beyond the plasma membrane and transduce changes in the external and internal environments into unique electrical signals to shape the responses of excitable cells.Because of their importance in cellular communication,ion channels have been intensively studied at the structural and functional levels.Here,we summarize the diverse approaches,including molecular and cellular,chemical,optical,biophysical,and computational,used to probe the structural and functional rearrangements that occur during channel activation（or sensitization）,inactivation（or desensitization）,and various forms of modulation.The emerging insights into the structure and function of ion channels by multidisciplinary approaches allow the development of new pharmacotherapies as well as new tools useful in controlling cellular activity.

Flavivirus RNA cap methyltransferase:structure,function,and inhibition

Many flaviviruses are significant human pathogens.The plus-strand RNA genome of a flavivirus contains a 5′terminal cap 1 structure(m7GpppAmG).The flavivirus encodes one methyltransferase(MTase),located at the Nterminal portion of the NS5 RNA-dependent RNA polymerase(RdRp).Here we review recent advances in our understanding of flaviviral capping machinery and the implications for drug development.The NS5 MTase catalyzes both guanine N7 and ribose 2'-OH methylations during viral cap formation.Representative flavivirus MTases,from dengue,yellow fever,and West Nile virus(WNV),sequentially generate GpppA!m7GpppA!m7GpppAm.Despite the existence of two distinct methylation activities,the crystal structures of flavivirus MTases showed a single binding site for S-adenosyl-L-methionine(SAM),the methyl donor.This finding indicates that the substrate GpppA-RNA must be repositioned to accept the N7 and 2'-O methyl groups from SAM during the sequential reactions.Further studies demonstrated that distinct RNA elements are required for the methylations of guanine N7 on the cap and of ribose 2'-OH on the first transcribed nucleotide.Mutant enzymes with different methylation defects can trans complement one another in vitro,demonstrating that separate molecules of the enzyme can independently catalyze the two cap methylations in vitro.In the context of the infectious virus,defects in both methylations,or a defect in the N7 methylation alone,are lethal to WNV.However,viruses defective solely in 2'-O methylation are attenuated and can protect mice from later wild-typeWNV challenge.The results demonstrate that the N7 methylation activity is essential for the WNV life cycle and,thus,methyltransferase represents a novel and promising target for flavivirus therapy.

Impacts of methamidophos,copper,and their combinations on bacterial community structure and function in black soil

The potential ecotoxicologial risks of methamidophos,copper,and their combinations on microbial community of black soil ecosystem in the Northeast China were assessed in species richness and structures by using 16S rDNA-PCR-DGGE analysis approach,and functional characteristics at community levels by using BIOLOG^(GN) system analysis method as well as two conventional methods(DHA and SIR).All results of DGGE banding fingerprint patterns(amplified by bacterial specific 16S rDNA V_(3) high variable region universal primer)indicated that the species richness of bacterial community in tested soil was significantly decreased to different extents by using different concentrations of single methamidophos,copper,especially some of their combinations had worse effects than their corresponding single factors.In addition,the structures of soil bacterial community had been disturbed under all stresses applied in this study because of the enrichment of some species and the disappearance of other species from the bacterial community.The effects of the single factors with lower concentrations on the communiy structure were weaker than those with higher concentrations.Moreover,the bacterial community structures under the combined stresses of methamidophos and copper were significantly different from those of control and their corresponding single factors.The change of DHA and carbon source substrate utilizing fingerprint patterns based on BIOLOG^(GN)system were two relatively sensitive directors corresponding to the stress presented in this study.Between methamodophos and copper,there happened the significant joint-toxic actions when they were used in combination on DHA and carbon source substrate utilizing fingerprint patterns of soil bacterial communities.The DHA of soil under the combined stresses was lower than that of the control and that under the single factors,and the BIOLOG^(GN) substrate utilizing patterns of soil treated by combinations were distinctively differentiated from the control and their corresponding single factors.From all of above,the methamidophos,copper,especially their combinations had the clearly potential ecotoxicological risks to influence the natural soil microbial ecological system by changing the structure,richness,and the functional characteristics of microbial community.

Solution structure and function of proteins relevant to pre-mRNA splicing

Pre-mRNA splicing is a dynamic process. It is catalyzed by the spliceosome which is a large machine formed by an ordered interactions of several small nuclear ribonucleoproteins, U1,

Review of forest ecology studies in China

As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.

Instant Effects of Radiofrequency Electromagnetic Wave on Hemoglobin in Single Living Intact Red Blood Cell

The absorption spectrum of the hemoglobin （Hb） in single riving intact red blood cell（RBC）, exposed in 900 MHz radiofrequency electromagnetic wave （RF-EMW）, was non-invasive,in situ, real-time measured by employing a highly sensitive fast multi-channel microspectrophotometer system. Both the absorption intensity and site of intracellular Hb were altered after RBCs were exposed in 900 MHz RF-EMW with power density at 5 mW/cm^2. It was indicated that not only the concentration of Hb in living RBCs was decreased, but the molecular structure of Hb was changed by the RF-EMW action.

Abnormal energy metabolism and tau phosphorylation in the brains of middle-aged mice in response to atmospheric PM2.5 exposure

In light of the accelerated aging of the global population and the deterioration of the atmosphere pollution, we sought to clarify the potential mechanisms by which fine particulate matter（PM_（2.5）） can cause cognitive impairment and neurodegeneration through the alteration of mitochondrial structure and function. The results indicate that PM_（2.5） inhalation reduces ATP production by disrupting the aerobic tricarboxylic acid cycle and oxidative phosphorylation, thereby causing the hypophosphorylation of tau in the cortices of middle-aged mice. Furthermore, excessive reactive oxygen species generation was involved in the impairment. Interestingly, these alterations were partially reversed after exposure to PM_（2.5） ended. These findings clarify the mechanism involved in mitochondrial abnormality-related neuropathological dysfunction in response to atmospheric PM_（2.5） inhalation and provide an optimistic sight for alleviating the adverse health outcomes in polluted areas.

Gastrointestinal tract(gut) health in the young pig

An optimally functioning gastrointestinal tract(GIT) clearly is of importance to the overall metabolism,physiology, disease status and performance of pigs of all stages of growth and development.Recently, the‘health’ of the GIT(‘gut health’) has attracted much attention despite the lack of a clear definition to the term or its aetiology, although in broad terms, ‘gut health’ encompasses a number of physiological and functional features including nutrient digestion and absorption, host metabolism and energy generation, a stable and appropriate microbiota/microbiome, defence mechanisms including barrier function and mucosal immune mechanisms, and the interactions between these components.‘Gut health’ in the newlyweaned(young) pig is of obvious interest due to changes in GIT structure and function associated with the post-weaning transition, and more recently to the upsurge in interest in different feed additives as dietary alternatives/replacements caused by bans/reductions in certain antimicrobial compounds being available in some parts of the world.In the presence of enteric disease(s) after weaning, a deterioration in ‘gut health’ may be synonymous to the overall health of the pig, and although some direct relationships can be drawn between pig performance and efficiency and a ‘healthy' GIT, sometimes this connection is subtler and less obvious, especially in the absence of overt enteric disease(s).The factors and conditions involved in ‘gut health’ are multifactorial, complex, often poorly described and sometimes incorrectly interpreted,although it is evident that perturbations of the GIT can cause an imbalance and disturb the generalized homeostasis.In addition to any enteric diseases or conditions that might arise as a result of these disturbances, other influences will also impact such as the responses occurring in the GIT in the period immediately after weaning, any changes that might occur after a change in diet, and(or) disruptions to meal patterns and hence the flow of nutrients.Ultimately, ‘gut health’ represents the outcome of the GIT in response to its capacity and ability to respond and adapt to the insults and challenges it encounters.

Human catalase: looking for complete identity

Catalases are well studied enzymes that play critical roles in protecting cells against the toxic effects of hydrogen peroxide.The ubiquity of the enzyme and the availability of substrates made heme catalases the focus of many biochemical and molecular biology studies over 100 years.In human,this has been implicated in various physiological and pathological conditions.Advancement in proteomics revealed many of novel and previously unknown features of this mysterious enzyme,but some functional aspects are yet to be explained.Along with discussion on future research area,this mini-review compile the information available on the structure,function and mechanism of action of human catalase.

The perinucleolar compartment associates with malignancy

The perinucleolar compartment （PNC） is a unique nuclear substructure, forming predominantly in cancer cells both in vitro and in vivo. PNC prevalence （percentage of cells containing at least one PNC） has been found to positively correlate with disease progression in several cancers （breast, ovarian, and colon）. While there is a clear association between PNCs and cancer, the molecular function of the PNC remains unclear. Here we summarize the current understanding of the association of PNCs with cancer and its possible functions in cancer cells.