Consumer characteristics and preferences for mobulid gill plates in China.

Mobulid species are endangered globally, and the market trade for gill plates is believed to be a major threat. Successful conservation and the sustainable use of mobulids therefore require an objective understanding of consumer characteristics and preferences for gill plates. Previous studies focused on qualitative descriptions, and reliable quantitative analyses are currently lacking. We used a latent class choice experiment method and a semistructured questionnaire to provide important new quantitative information about gill plate consumer characteristics and the heterogeneous nature of demand for gill plates. From May to July 2019, we conducted a field study in Guangzhou, the primary consumption hub for mobulid gill plates in mainland China. Utilizing a simple random sampling method, we engaged in face-to-face interviews with 428 consumers of gill plates in the major trading markets in Guangzhou. Our results showed that 59.8% of consumers of gill plates were over 40 years old, 62.6% were female, 80.7% had annual household incomes of <200,000 yuan, and 84.5% recognized the medical and health value of gill plates and purchased them. About seventy-two percent of consumers preferred to purchase imported and less expensive gill plates from unprotected species, but they had a strong preference for large gill plates from protected species, such as Mobula birostris. This contradiction arose from consumers' lack of knowledge of mobulids and their conservation status. We found, for example, female consumers over 40 years old had the least understanding of conservation status of mobulid species and the link between size of gill plates and rarity of mobulids. This suggests there may be opportunities to promote mobulid conservation through education and marketing targeted at this demographic. Consumers who had a positive preference for gill plates from protected species (regardless of price) (10%) may be harder to influence. Overall, we believe education alone is not enough and that the conservation of mobulids would benefit from an integrated approach that involves conservation education and strengthened trade regulations, such as the introduction of traceability systems and a stiffer legal framework for consumption of protected species.

Características y preferencias de los consumidores de placas branquiales de mobúlidos en China Resumen Las especies de mobúlidos están en peligro de extinción en todo el mundo y se considera al mercado de placas branquiales como una amenaza principal. Por lo tanto, la conservación exitosa y el uso sustentable de los mobúlidos requiere del entendimiento objetivo de las características y preferencias de los consumidores de estas placas branquiales. Los estudios previos se han enfocado en descripciones cualitativas, por lo que actualmente no hay suficientes análisis cuantitativos confiables. Usamos un método de experimento de elección de clase latente y un cuestionario semiestructurado para proporcionar información cuantitativa nueva e importante sobre las características de los consumidores de placas branquiales y la naturaleza heterogénea de la demanda de estas placas. Realizamos un estudio de campo entre mayo y julio de 2019 en Guangzhou, el principal centro de consumo de placas branquiales de mobúlidos en el interior de China. Utilizamos un método de muestreo aleatorio simple para entrevistar cara­a­cara a 428 consumidores de placas branquiales en los principales mercados de Guangzhou. Nuestros resultados mostraron que el 59.8% de los consumidores son mayores a 40 años, 62.6% son mujeres, 80.7% tienen un ingreso doméstico anual mayor a 200,000 yuan y 84.5% reconocieron el valor médico y para la salud que tienen las placas branquiales, razones por las que las compran. El 72% de los consumidores prefirió comprar las placas importadas y menos caras de especies no protegidas, aunque tuvieron una mayor preferencia por las placas más grandes de las especies protegidas, como Mobula birostris. Esta contradicción se debe a la falta de conocimiento que tienen los consumidores sobre los mobúlidos y su estado de conservación. Descubrimos que, por ejemplo, las consumidoras de más de 40 años tienen el menor conocimiento del estado de conservación de los mobúlidos y la conexión entre el tamaño de las placas branquiales y la rareza de la especie. Lo anterior sugiere que podría haber oportunidad de promover la conservación de los mobúlidos por medio de la educación y la mercadotecnia enfocada en este grupo demográfico. Podría ser más difícil influir sobre el 10 % de los consumidores, el cual tiene una preferencia positiva por las placas branquiales de las especies protegidas (sin importar el precio). En general creemos que la educación por sí sola no es suficiente y que la conservación de los mobúlidos se beneficiaría de una estrategia integrada que involucre la educación para la conservación y regulaciones de mercado fortalecidas, como la introducción de los sistemas de trazabilidad y un marco legal más rígido para el consumo de las especies protegidas.

Hepatic cytochromes P450: structural degrons and barcodes, posttranslational modifications and cellular adapters in the ERAD-endgame.

The endoplasmic reticulum (ER)-anchored hepatic cytochromes P450 (P450s) are enzymes that metabolize endo- and xenobiotics i.e. drugs, carcinogens, toxins, natural and chemical products. These agents modulate liver P450 content through increased synthesis or reduction via inactivation and/or proteolytic degradation, resulting in clinically significant drug-drug interactions. P450 proteolytic degradation occurs via ER-associated degradation (ERAD) involving either of two distinct routes: Ubiquitin (Ub)-dependent 26S proteasomal degradation (ERAD/UPD) or autophagic lysosomal degradation (ERAD/ALD). CYP3A4, the major human liver/intestinal P450, and the fast-turnover CYP2E1 species are degraded via ERAD/UPD entailing multisite protein phosphorylation and subsequent ubiquitination by gp78 and CHIP E3 Ub-ligases. We are gaining insight into the nature of the structural determinants involved in CYP3A4 and CYP2E1 molecular recognition in ERAD/UPD [i.e. K48-linked polyUb chains and linear and/or "conformational" phosphodegrons consisting either of consecutive sequences on surface loops and/or disordered regions, or structurally-assembled surface clusters of negatively charged acidic (Asp/Glu) and phosphorylated (Ser/Thr) residues, within or vicinal to which, Lys-residues are targeted for ubiquitination]. Structural inspection of select human liver P450s reveals that such linear or conformational phosphodegrons may indeed be a common P450-ERAD/UPD feature. By contrast, although many P450s such as the slow-turnover CYP2E1 species and rat liver CYP2B1 and CYP2C11 are degraded via ERAD/ALD, little is known about the mechanism of their ALD-targeting. On the basis of our current knowledge of ALD-substrate targeting, we propose a tripartite conjunction of K63-linked Ub-chains, P450 structural "LIR" motifs and selective cellular "cargo receptors" as plausible P450-ALD determinants.

Classification and interaction modes of 40 rice E2 ubiquitin-conjugating enzymes with 17 rice ARM-U-box E3 ubiquitin ligases.

Rice, a monocot model crop, contains at least 48 putative E2 ubiquitin (Ub)-conjugating enzymes. Based on homology comparisons with 40 Arabidopsis E2 proteins and 35 human E2s, 48 rice E2s were classified into 15 different groups. Yeast two-hybrid analyses using the U-box-domain regions of armadillo (ARM)-U-box E3 Ub-ligases and the Ub-conjugating (UBC) domains of E2s showed that, among 40 rice E2s, 11 E2s accounted for 70% of the interactions with 17 ARM-U-box E3s. Thus, a single E2 could interact with multiple ARM-U-box E3s, suggesting the presence of E2 hubs for E2-E3 interactions in rice. Rice SPL11 ARM-U-box E3 displayed distinct self-ubiquitination patterns, including poly-ubiquitination, mono-ubiquitination, or no ubiquitination, depending on different E2 partners. This suggests that the mode of ubiquitination of SPL11 E3 is critically influenced by individual E2s.

Hepatic cytochrome P450 ubiquitination: conformational phosphodegrons for E2/E3 recognition?

Hepatic endoplasmic reticulum (ER) integral cytochromes P450 (P450s) are monooxygenases engaged in the biotransformation and elimination of endo- as well as xenobiotics. Of the human liver P450s, CYP3A4 is the major and most dominant catalyst responsible for the biotransformation of over 50% of clinically prescribed drugs. CYP2E1 metabolizes smaller molecular weight compounds (EtOH), carcinogens, environmental toxins, and endobiotics, and is justly implicated in various toxigenic/pathogenic mechanisms of human disease. Both P450s are notorious for their potential to generate pathogenic reactive oxygen species (ROS) during futile oxidative cycling and/or oxidative uncoupling. Such ROS not only oxidatively damage the P450 catalytic cage, but on their escape into the cytosol, also the P450 outer surface and any surrounding cell organelles. Given their ER-monotopic topology coupled with this high potential to acquire oxidative lesions in their cytosolic (C) domain, not surprisingly these P450 proteins exhibit shorter lifespans and are excellent prototype substrates of ER-associated degradation ("ERAD-C") pathway. Indeed, we have shown that both CYP3A4 and CYP2E1 incur ERAD-C, during which they are first phosphorylated by protein kinases A and C, which greatly enhance/accelerate their ubiquitination by UBC7/gp78 and UbcH5a/CHIP/Hsp70/Hsp40 E2/E3 ubiquitin ligase complexes. Such P450 phosphorylation occurs on Ser/Thr residues within linear sequences as well as spatially clustered acidic (Asp/Glu) residues. We propose that such S/T phosphorylation within these clusters creates negatively charged patches or conformational phosphodegrons for interaction with positively charged E2/E3 domains. Such P450 S/T phosphorylation we posit serves as a molecular switch to turn on its ubiquitination and ERAD-C.

ER-associated ubiquitin-conjugating enzyme: a key regulator of grain yield and stress resistance in crops.

Recent research reveals the critical roles of endoplasmic reticulum (ER)-associated protein degradation (ERAD)-related ubiquitin-conjugating enzyme AtUBC32 orthologs and their partnering E3 ligases, which play dual roles in enhancing both crop yield and stress resistance. These findings open avenues for breeding high-yield, stress-tolerant crops and inspire further exploration of the ERAD pathway in agricultural innovation.

DGS1 improves rice disease resistance by elevating pathogen-associated molecular pattern-triggered immunity.

Rice yield and disease resistance are two crucial factors in determining the suitability of a gene for agricultural breeding. Decreased grain size1 (DGS1), encoding an RING-type E3 ligase, has been found to have a positive effect on rice yield by regulating rice grain number and 1000-grain weight. However, the role of DGS1 in rice blast resistance is still unknown. In this study, we report that DGS1 enhances disease resistance by improving PTI responses, including stronger ROS burst and MAPK activation, and also increased expression of defense-related genes. Furthermore, DGS1 works in conjunction with ubiquitin conjugating enzyme OsUBC45 as an E2-E3 pair to facilitate the ubiquitin-dependent degradation of OsGSK3 and OsPIP2;1, thereby influencing rice yield and immunity, respectively. Therefore, the DGS1-OsUBC45 module has the potential in facilitating rice agricultural breeding. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-024-00137-9.

When an underdog becomes a major player: the role of protein structural disorder in the Atg8 conjugation system.

The noncanonical ubiquitin-like conjugation cascade involving the E1 (Atg7), E2 (Atg3, Atg10), and E3 (Atg12-Atg5-Atg16 complex) enzymes is essential for incorporation of Atg8 into the growing phagophore via covalent linkage to PE. This process is an indispensable step in autophagy. Atg8 and E1-E3 enzymes are the first subset from the core autophagy protein machinery structures that were investigated in earlier studies by crystallographic analyses of globular domains. However, research over the past decade shows that many important functions in the conjugation machinery are mediated by intrinsically disordered protein regions (IDPRs) - parts of the protein that do not adopt a stable secondary or tertiary structure, which are inherently dynamic and well suited for protein-membrane interactions but are invisible in protein crystals. Here, we summarize earlier and recent findings on the autophagy conjugation machinery by focusing on the IDPRs. This summary reveals that IDPRs, originally considered dispensable, are in fact major players and a driving force in the function of the autophagy conjugation system. Abbreviation: AD, activation domain of Atg7; AH, amphipathic helix; AIM, Atg8-family interacting motif; CL, catalytic loop (of Atg7); CTD, C-terminal domain; FR, flexible region (of Atg3 or Atg10); GUV, giant unilammelar vesicles; HR, handle region (of Atg3); IDPR, intrinsically disordered protein region; IDPs: intrinsically disordered proteins; LIR, LC3-interacting region; NHD: N-terminal helical domain; NMR, nuclear magnetic resonance; PE, phosphatidylethanolamine; UBL, ubiquitin like.

Identification and Characterization of Physiological Pairing of E2 Ubiquitin-Conjugating Enzymes and E3 Ubiquitin Ligases.

The posttranslational attachment of the small protein modifier ubiquitin (Ub) is best known for its function in targeting proteins for degradation by the proteasome. However, ubiquitination also serves as a signal determining protein localization, activity, and interaction. Ubiquitination requires the sequential activity of E1 ubiquitin-activating enzyme (UBA), E2 ubiquitin-conjugating enzyme (UBC), and E3 ubiquitin ligase. Recognition of a target protein by an Ub-E2-E3 complex can result in its mono-ubiquitination (attachment of a single Ub moiety) or poly-ubiquitination, i.e., attachment of Ub chains. While the E3 ligase is important for the reaction specificity, the E2s catalyze the attachment of Ub to the target and to Ub itself to generate chains. In Arabidopsis thaliana, there are two E1s, 37 UBCs (and two ubiquitin-like conjugating enzymes) and more than 1400 E3 ligases, working in a combinatorial way. Therefore, in order to understand E3 ligase function, it is important to frame it within its possible E2s interactors. In this chapter, we propose a two-step identification and characterization of physiological E2-E3 pairs. In a first step, in vivo interacting E2s are identified through bimolecular fluorescence complementation (BiFC) using transient expression in Arabidopsis protoplast. In the second step, the activity of E2-E3 pairs is analyzed by a synthetic biology approach in which autoubiquitination is reconstituted in bacteria.

E2-E3 ubiquitin enzyme pairing - partnership in provoking or mitigating cancers.

The ubiquitin-proteasome system (UPS) modulates carcinogenesis through ubiquitination of cancer-related target proteins, leading to their degradation in the proteasome. This may deactivate tumor suppressors or activate tumor promoters- either way causing homeostatic imbalance. As major components of the UPS, the E2 and E3 enzymes are recognized as pivotal determinants of substrate recognition and ubiquitination. Identification of E2-E3 pairing selectivity is particularly pertinent to early diagnosis and potential development of targeted cancer therapeutics. This review is motivated by recent findings and new insights into the molecular dynamics of ubiquitination triggered by specific E2-E3 pairing, leading to cancer initiation and progression if cancer suppressors are degraded or cancer suppression (if cancer promoters are degraded), respectively. We provide an overview of strategies employed in screening for E2-E3 interactions based on up-to-date studies focusing on the E2-E3 interface motifs. Of considerable recent interest is how E2 and E3 might switch their functional partnerships via UBE2O, which suggests an emerging significance on how UBE2O might influence E2-E3 pairing. Thus, a reflection on the role of UBE2O is included. Finally, we deliberate on the rational and cautious development of anti-cancer cocktail drugs which specifically target E2-E3 interacting residues for precision in cancer-killing with minimal side-effects. To this end, a list of potential future research is proposed.

Degradation of acetaminophen in photo-enzyme coupling system with natural organic matters from different sources.

Acetaminophen (AAP) is one of the most commonly prescribed over-the-counter drugs with wide distribution in surface water, which has attracted great attention around the world. Photodegradation and enzymatic transformation are important processes for the removal of AAP in water. The influence of natural organic matter (NOM) from different sources on the transformation of AAP by horseradish peroxidase (HRP) in sunlit water was systematically studied. NOM can effectively promote the combined degradation rate of AAP in photo-enzyme coupling system (PECS), and the promotion extents of different NOMs were dependent on their aromaticity and average molecular weights. NOM with low aromaticity and low average molecular weight is more effective. In order to disclose the underlying effects of NOM clearly, the reaction mechanism was clarified through the determination of the photodegradation constant and enzymatic reaction constant. The effect of NOM structure on the photo-enzymatic transformation of AAP was quantified, which showed significant positive correlation with the SUVA254 and E2/E3 of NOM. Further investigation revealed that the amount of H2O2 generated by NOM from different sources was also closely related to SUVA254 and E2/E3 of NOM. The findings will facilitate understanding the environmental fate of AAP and other pharmaceutical products in natural water.

ApoE e2 and aging-related outcomes in 379,000 UK Biobank participants.

The Apolipoprotein E (APOE) e4 allele is associated with reduced longevity and increased Coronary Artery Disease (CAD) and Alzheimer's disease, with e4e4 having markedly larger effect sizes than e3e4. The e2 longevity promoting variant is less studied. We conducted a phenome-wide association study of ApoE e2e3 and e2e2 with aging phenotypes, to assess their potential as targets for anti-aging interventions. Data were from 379,000 UK Biobank participants, aged 40 to 70 years. e2e3 (n=46,535) had mostly lower lipid-related biomarker levels including reduced total and LDL-cholesterol, and lower risks of CAD (Odds Ratio=0.87, 95% CI: 0.83 to 0.90, p=4.92×10-14) and hypertension (OR=0.94, 95% CI: 0.92 to 0.97, p=7.28×10-7) versus e3e3. However, lipid changes in e2e2 (n=2,398) were more extreme, including a marked increase in triglyceride levels (0.41 Standard Deviations, 95% CI: 0.37 to 0.45, p=5.42×10-92), with no associated changes in CAD risks. There were no associations with biomarkers of kidney function. The effects of both e2e2 and e2e3 were minimal on falls, muscle mass, grip strength or frailty. In conclusion, e2e3 has protective effects on some health outcomes, but the effects of e2e2 are not similar, complicating the potential usefulness of e2 as a target for anti-aging intervention.

Structural basis of generic versus specific E2-RING E3 interactions in protein ubiquitination.

Protein ubiquitination is a fundamental regulatory component in eukaryotic cell biology, where a cascade of ubiquitin activating (E1), conjugating (E2), and ligating (E3) enzymes assemble distinct ubiquitin signals on target proteins. E2s specify the type of ubiquitin signal generated, while E3s associate with the E2~Ub conjugate and select the substrate for ubiquitination. Thus, producing the right ubiquitin signal on the right target requires the right E2-E3 pair. The question of how over 600 E3s evolved to discriminate between 38 structurally related E2s has therefore been an area of intensive research, and with over 50 E2-E3 complex structures generated to date, the answer is beginning to emerge. The following review discusses the structural basis of generic E2-RING E3 interactions, contrasted with emerging themes that reveal how specificity can be achieved.

Dissolved organic carbon in a constructed and natural fens in the Athabasca oil sands region, Alberta, Canada.

In the Athabasca oil sands region near Fort McMurray, Alberta, Canada, peatlands are disturbed extensively in order to recover bitumen below the surface. Hence, following oil sands mining, landscape reclamation is a part of the mine closure process in order to return functioning ecosystems, including peatlands, to the region. This study was conducted at a pilot fen reclamation project and three other diverse natural (poor, rich and saline) fens in the oil sands region during the growing seasons of 2013 and 2014, the first and second year post-construction. Ecosystem functioning of the constructed fen (CF) was evaluated with reference to natural fens based on pore water dissolved organic carbon (DOC) concentration and chemistry. Significant variation of DOC concentration among the reference fens was observed, varying from an average of 42.0mg/L at the rich fen (RF) to 70.8mg/L at the saline fen (SF). Dissolved organic carbon concentration at CF was significantly lower than at all reference fens, but increased significantly over the first two years. Seasonal variation of DOC concentration was also observed in each site with concentration increasing over the growing season. At CF, DOC was comprised of larger, more humic and complex aromatic compounds than reference fens in the first year post-construction based on its spectrophotometric properties; however, these differences were reduced in the second year. Initial DOC concentration and chemistry at CF was indicative of the source being largely the peat placed during fen construction. Changes in chemistry and increasing concentration of DOC in the second growing season likely resulted from increasing inputs from plants established on site. These results suggest that DOC concentration is likely to increase in future at CF as vascular plant productivity increases and in response to salinity sourced from tailing sand used to construct the catchment.

Binding to E1 and E3 is mutually exclusive for the human autophagy E2 Atg3.

Ubiquitin-like proteins (UBLs) are activated, transferred and conjugated by E1-E2-E3 enzyme cascades. E2 enzymes for canonical UBLs such as ubiquitin, SUMO, and NEDD8 typically use common surfaces to bind to E1 and E3 enzymes. Thus, canonical E2s are required to disengage from E1 prior to E3-mediated UBL ligation. However, E1, E2, and E3 enzymes in the autophagy pathway are structurally and functionally distinct from canonical enzymes, and it has not been possible to predict whether autophagy UBL cascades are organized according to the same principles. Here, we address this question for the pathway mediating lipidation of the human autophagy UBL, LC3. We utilized bioinformatic and experimental approaches to identify a distinctive region in the autophagy E2, Atg3, that binds to the autophagy E3, Atg12∼Atg5-Atg16. Short peptides corresponding to this Atg3 sequence inhibit LC3 lipidation in vitro. Notably, the E3-binding site on Atg3 overlaps with the binding site for the E1, Atg7. Accordingly, the E3 competes with Atg7 for binding to Atg3, implying that Atg3 likely cycles back and forth between binding to Atg7 for loading with the UBL LC3 and binding to E3 to promote LC3 lipidation. The results show that common organizational principles underlie canonical and noncanonical UBL transfer cascades, but are established through distinct structural features.

Immunomodulatory and therapeutic effects of Hot-nature diet and co-supplemented hemp seed, evening primrose oils intervention in multiple sclerosis patients.

BACKGROUND: Multiple sclerosis (MS) is the most chronic and inflammatory disorder. Because of limited efficacy and adverse side effects, identifying novel therapeutic and protective agents is important. This study was aimed to assess the potential therapeutic effects of hemp seed and evening primrose oils as well as Hot-nature dietary intervention on RRMS patients. METHODS AND MATERIALS: In this double blind, randomized trial, 100 MS patients with EDSS<6 were allocated into 3 groups: "Group A" who received co-supplemented hemp seed and evening primrose oils with advised Hot-nature diet, "Group B" who received olive oil, "Group C" who received the co-supplemented oils. Mizadj, clinically EDSS and relapse rate as well as immunological factors (IL-4, IFN-γ and IL-17) were assessed at baseline and after 6 months. RESULTS: Mean follow-up was 180±2.9 SD days (N=65, 23 M and 42 F aged 34.25±8.07 years with disease duration 6.80±4.33 years). There was no significant difference in studies parameters at baseline. After 6 months, significant improvements in Mizadj, EDSS and relapse rate were found in the groups A and C, while the group B showed a border significant decrease in relapse rate. Immunological parameters showed improvement in groups A and C, whereas there was worsening condition for group B after the intervention. CONCLUSION: The co-supplemented hemp seed and evening primrose oils with Hot-nature diet have beneficial effects in improving of clinical score in RRMS patients which were confirmed by immunological findings.