Dual protection by Bcp1 and Rkm1 ensures incorporation of uL14 into pre-60S ribosomal subunits.

Eukaryotic ribosomal proteins contain extended regions essential for translation coordination. Dedicated chaperones stabilize the associated ribosomal proteins. We identified Bcp1 as the chaperone of uL14 in Saccharomyces cerevisiae. Rkm1, the lysine methyltransferase of uL14, forms a ternary complex with Bcp1 and uL14 to protect uL14. Rkm1 is transported with uL14 by importins to the nucleus, and Bcp1 disassembles Rkm1 and importin from uL14 simultaneously in a RanGTP-independent manner. Molecular docking, guided by crosslinking mass spectrometry and validated by a low-resolution cryo-EM map, reveals the correlation between Bcp1, Rkm1, and uL14, demonstrating the protection model. In addition, the ternary complex also serves as a surveillance point, whereas incorrect uL14 is retained on Rkm1 and prevented from loading to the pre-60S ribosomal subunits. This study reveals the molecular mechanism of how uL14 is protected and quality checked by serial steps to ensure its safe delivery from the cytoplasm until its incorporation into the 60S ribosomal subunit.

Protocol for phospho-SrcKD: rPTPεD1 complex preparation and BLI binding assays to demonstrate their exosite interface.

Here, we present a protocol for the in vitro phosphorylation of Src kinase domain (SrcKD), preparation of phospho-SrcKD in complex with the D1 domain of rPTP epsilon (rPTPεD1), and binding assays using biolayer interferometry (BLI). We describe steps for the in vitro phosphorylation of SrcKD and preparation of the phospho-SrcKD: rPTPεD1 complex for small-angle X-ray scattering (SAXS) experiments. We then detail instructions for the BLI binding assay to determine the binding affinity between phospho-SrcKD and rPTPεD1. For complete details on the use and execution of this protocol, please refer to EswarKumar et al.1.

Occupational exposure limits for reproductive toxicants - A comparative analysis.

We investigated the level of protection of reproductive and developmental toxicity offered through occupational exposure limits (OELs) and Derived No-Effect Levels for workers' inhalation exposure (wDNELs). We compared coverage of substances that have a harmonised classification as reproductive toxicant 1 A or 1B (Repr.1 A/B), numerical values and scientific basis of 12 lists of OELs and wDNELs from REACH Registrants' and the Committee for Risk Assessment. Across the 14 sources of OELs and wDNELs, 53 % of the Repr1A/B-substances had at least one exposure limit (counting groups of metals as one entry). Registrants' wDNELs covered the largest share, 40 %. The numerical values could be highly variable for the same substance across the lists. How often reproductive toxicity is identified as the critical effect varies between the examined lists, both due to different assessments of the same substance and different substance coverage. Reviewing the margin of safety to reproductive toxicity cited in the documents, we found that 15 % of safety margins were lower to reproductive toxicity than the critical effect. To conclude, neither the REACH nor work environment legislation supply wDNELs or OELs for a substantial share of known reproductive toxicants. EU OELs cover among the fewest substances in the range, and in many cases national OELs or wDNELs are set at more conservative levels.

Dosimetric Correlation of Acute Radiation Dermatitis in Patients With Breast Cancer Undergoing Hypofractionated Proton Beam Therapy Using Pencil Beam Scanning.

PURPOSE: Pencil-beam scanning (PBS) is a modern delivery technique used in proton beam therapy (PBT) to reduce normal tissue reactions. No dosimetric correlation between dermatitis and PBS has been reported for breast cancer. The current study aimed to investigate the factors associated with grade 2 or higher dermatitis in patients with breast cancer undergoing PBT using PBS. METHODS: The medical data of 42 patients with breast cancer who underwent adjuvant radiotherapy between December 2019 and September 2023 were reviewed. All patients received hypofractionated radiotherapy (HFRT), either 26 Gy (relative biological effectiveness [RBE])/five fractions or 40.05 or 43.5 Gy (RBE)/15 fractions, for the whole breast/chest wall with or without nodal irradiation. The duration of acute radiation dermatitis was defined as within 90 days from the start of radiotherapy. The Kaplan-Meier method and Cox proportional hazards model were used for univariate and multivariate analyses of the actuarial rates of grade 2-3 dermatitis. RESULTS: Twenty-two (52.4%) and 20 (47.6%) patients were diagnosed with grade 1 and 2 dermatitis, respectively. Multivariate analysis revealed a clinical target volume (CTV) ≥ of 320 cc (p = 0.035) and a skin dose of D10cc ≥ 38.3 Gy (RBE) (p = 0.009) as independent factors of grade 2 dermatitis. The 10-week cumulative grade 2 dermatitis rates were 88.2%, 39.4%, and 8.3% (p < 0.001) for patients with both high, either high, and neither high CTV and D10cc, respectively. CONCLUSION: To the best of our knowledge, this is the first study on dosimetric correlations for dermatitis in patients with breast cancer who underwent hypofractionated PBT using PBS. In the era of HFRT, skin dose modulation using PBS may reduce the incidence of dermatitis.

Invasive pulmonary aspergillosis among patients with severe community-acquired pneumonia and influenza in ICUs: a retrospective cohort study.

RATIONALE: The prevalence, clinical characteristics, and outcomes of invasive pulmonary aspergillosis in patients with severe community-acquired pneumonia (CAP) in intensive care units remain underestimated because of the lack of a disease-recognition scheme and the inadequacy of diagnostic tests. OBJECTIVES: To identify the prevalence, risk factors, and outcomes of severe CAP complicated with invasive pulmonary aspergillosis (IPA) in intensive care units (ICUs). METHODS: We conducted a retrospective cohort study including recruited 311 ICU-hospitalized patients with severe CAP without influenza or with influenza. Bronchoalveolar lavage fluid (BALF) samples were from all patients and subjected to mycological testing. Patients were categorized as having proven or probable Aspergillus infection using a modified form of the AspICU algorithm comprising clinical, radiological, and mycological criteria. MEASUREMENTS AND MAIN RESULTS: Of the 252 patients with severe CAP and 59 influenza patients evaluated, 24 met the diagnostic criteria for proven or probable Aspergillus infection in the CAP group and 9 patients in the influenza group, giving estimated prevalence values of 9.5% and 15.3%, respectively. COPD and the use of inhaled corticosteroids were independent risk factors for IPA. IPA in patients with severe CAP was significantly associated with the duration of mechanical support, the length of ICU stay, and the 28-day mortality. CONCLUSIONS: An aggressive diagnostic approach for IPA patients with severe CAP and not only influenza or COVID-19 should be pursued. Further randomized controlled trials need to evaluate the timing, safety, and efficacy of antifungal therapy in reducing IPA incidence and improving clinical outcomes.

Factors associated with depression, anxiety, and satisfaction with life among Malaysian parental caregivers of adolescent psychiatric patients: A cross-sectional study.

Depression and anxiety are prevalent mental health issues worldwide, especially among parental caregivers. By expanding the family stress model, this cross-sectional study investigated the relevant factors associated with depressive symptoms, anxiety symptoms, and satisfaction with life among Malaysian parental caregivers of adolescent psychiatric patients. Data were collected through questionnaires (N = 207) across five major public hospitals through convenience sampling. Participants answered questionnaires measuring financial strain, caregiver burden, relationship quality, belief in mental illness, perceived COVID-19 stress, satisfaction with health services, depressive symptoms, anxiety symptoms and life satisfaction. Findings revealed that relationship quality among spouses, COVID-19 stress and caregiver burden were significantly correlated with anxiety symptoms, depressive symptoms and satisfaction with life. The multiple regression model also suggested that depressive symptoms (ß = .613, p < .001), anxiety symptoms (ß= .657, p < .001) and relationship quality among spouses (ß = .264, p < .001) were the most influential predictors of anxiety symptoms, depressive symptoms and satisfaction with life respectively. By addressing the mental health needs of parental caregivers, this study can contribute to improving the overall quality of care and support provided to adolescent patients and their caregivers in Malaysia and beyond.

Polynucleotides HPT for Asian Skin Regeneration and Rejuvenation.

Introduction: Even lightly compromised skin may impact self-esteem and social behaviour. After intradermal infiltration, natural-origin Polynucleotides High Purification Technology (PN HPT) promote new collagen and extracellular matrix production, translating into a physiological correction of the ageing skin. The study aimed to explore the benefits of intradermal PN HPT on the four perceptual skin quality categories "Skin Tone Evenness", "Skin Surface Evenness", "Skin Firmness", and "Skin Glow" in a representative sample of 30 Asian subjects (mean age 40.2± 11.4 years old). Methods: Study protocol: three intradermal injections of a PN HPT-based Class III CE-marked medical device at T0 (baseline assessment and first treatment session), T1 (four weeks after baseline), and T2 (eight weeks after baseline), with efficacy and safety evaluations at T1, T2, T3 (four months after baseline) and T4 (six months after baseline). Quantitative and qualitative assessments: 3D skin analysis system QuantifiCare and Global Aesthetic Improvement Scale (GAIS, Investigator and Patient subscales). Results: PN HPT treatment led to a meaningful and statistically significant improvement of the skin surface, firmness, pigmentation, and radiance, with no early- or late-onset adverse events and benefits persisting up to the sixth-month visit in all subjects. At T4, 33% and 43% of treated subjects felt "Much Improved" and "Very Much Improved" (optimal result); 56% and 44% of treated subjects felt "Satisfied" or "Very Satisfied". At T4, the mean Investigator GAIS scores were 3.33 out of 5.0 for the "Skin Tone Evenness" skin quality perceptual category, 3.46 for the "Skin Surface Evenness" category, 3.61 for "Skin Firmness", and 3.45 per for the radiance determinant of the "Skin Glow" category. Conclusion: Intradermal treatment with the PN HPT-based medical device led to a meaningful improvement of the skin surface, firmness, pigmentation, and radiance with complete safety. The aesthetic benefits persisted up to the sixth-month visit in all subjects.

Pb(NO3 )2 induces cell apoptosis through triggering of reactive oxygen species accumulation and disruption of mitochondrial function via SIRT3/SOD2 pathways.

Lead (Pb) is nonbiodegradable and toxic to the lungs. To investigate the potential mechanisms of Pb-induced reactive oxygen species (ROS) accumulation and cell death in the lungs, human non-small lung carcinoma H460 cells were stimulated with Pb(NO3 )2 in this study. The results showed that Pb(NO3 )2 stimulation increased cell death by inducing cell apoptosis which showed a reduced Bcl-2 expression and an enhanced caspase 3 activation. Pb(NO3 )2 also caused the production of H2 O2 in H460 cells that triggering the buildup of ROS and mitochondrial membrane potential loss. We found that Pb(NO3 )2 modulates oxidoreductive activity through reduced the glutathione-disulfide reductase and glutathione levels in Pb(NO3 )2 -exposed H460 cells. Furthermore, the superoxide dismutase (SOD) upstream molecule sirtuin 3 (SIRT3) was increased with Pb(NO3 )2 dose. Collectively, these results demonstrate that Pb(NO3 )2 promotes lung cell death through SIRT3/SOD-mediated ROS accumulation and mitochondrial dysfunction.

A structure of the relict phycobilisome from a thylakoid-free cyanobacterium.

Phycobilisomes (PBS) are antenna megacomplexes that transfer energy to photosystems II and I in thylakoids. PBS likely evolved from a basic, inefficient form into the predominant hemidiscoidal shape with radiating peripheral rods. However, it has been challenging to test this hypothesis because ancestral species are generally inaccessible. Here we use spectroscopy and cryo-electron microscopy to reveal a structure of a "paddle-shaped" PBS from a thylakoid-free cyanobacterium that likely retains ancestral traits. This PBS lacks rods and specialized ApcD and ApcF subunits, indicating relict characteristics. Other features include linkers connecting two chains of five phycocyanin hexamers (CpcN) and two core subdomains (ApcH), resulting in a paddle-shaped configuration. Energy transfer calculations demonstrate that chains are less efficient than rods. These features may nevertheless have increased light absorption by elongating PBS before multilayered thylakoids with hemidiscoidal PBS evolved. Our results provide insights into the evolution and diversification of light-harvesting strategies before the origin of thylakoids.

A 5+1 assemble-to-activate mechanism of the Lon proteolytic machine.

Many AAA+ (ATPases associated with diverse cellular activities) proteins function as protein or DNA remodelers by threading the substrate through the central pore of their hexameric assemblies. In this ATP-dependent translocating state, the substrate is gripped by the pore loops of the ATPase domains arranged in a universal right-handed spiral staircase organization. However, the process by which a AAA+ protein is activated to adopt this substrate-pore-loop arrangement remains unknown. We show here, using cryo-electron microscopy (cryo-EM), that the activation process of the Lon AAA+ protease may involve a pentameric assembly and a substrate-dependent incorporation of the sixth protomer to form the substrate-pore-loop contacts seen in the translocating state. Based on the structural results, we design truncated monomeric mutants that inhibit Lon activity by binding to the native pentamer and demonstrated that expressing these monomeric mutants in Escherichia coli cells containing functional Lon elicits specific phenotypes associated with lon deficiency, including the inhibition of persister cell formation. These findings uncover a substrate-dependent assembly process for the activation of a AAA+ protein and demonstrate a targeted approach to selectively inhibit its function within cells.

Fear of detachment from mobile phone: nomophobia and suicidality among Malaysian university students before and during the COVID-19 pandemic.

The attachment to mobile devices during the COVID-19 pandemic has led to the possibility of increased nomophobia, which is the intense fear of losing access to one's mobile device. Therefore, this study aimed to determine if nomophobia was independently associated with suicidality before and during the COVID-19 pandemic among university students in Malaysia. This cross-sectional study had two-time points in data collection: one year before and one year into the COVID-19 pandemic. N = 806 university students aged ≥ 18 years completed an online questionnaire comprising the Nomophobia Questionnaire, Multidimensional Scale of Perceived Social Support, and the Suicidal Behaviors Questionnaire-Revised. A multiple logistic regression (controlling for gender, age, and social support) was conducted to determine the association between nomophobia and suicidality before and during the COVID-19 pandemic. The prevalence of severe nomophobia before and during the COVID-19 pandemic was 15.7% and 35.6% respectively. The level of nomophobia was significantly higher during the COVID-19 pandemic compared to pre-pandemic. Pre-pandemic, there were no significant associations. During the pandemic, participants with moderate (aOR 3.09, 95% CI [1.14-8.40], p = .027) and severe (aOR 3.57, 95% CI [1.25-10.20], p = .018) nomophobia had higher odds of suicide plan. During the pandemic, moderate and severe nomophobia were independently associated with more than three times higher odds for a lifetime suicide plan. Our study findings carry implications for the well-being of university students.

An integrative approach unveils a distal encounter site for rPTPε and phospho-Src complex formation.

The structure determination of protein tyrosine phosphatase (PTP): phospho-protein complexes, which is essential to understand how specificity is achieved at the amino acid level, remains a significant challenge for protein crystallography and cryoEM due to the transient nature of binding interactions. Using rPTPεD1 and phospho-SrcKD as a model system, we have established an integrative workflow to address this problem, by means of which we generate a protein:phospho-protein complex model using predetermined protein structures, SAXS and pTyr-tailored MD simulations. Our model reveals transient protein-protein interactions between rPTPεD1 and phospho-SrcKD and is supported by three independent experimental validations. Measurements of the association rate between rPTPεD1 and phospho-SrcKD showed that mutations on the rPTPεD1: SrcKD complex interface disrupts these transient interactions, resulting in a reduction in protein-protein association rate and, eventually, phosphatase activity. This integrative approach is applicable to other PTP: phospho-protein complexes and the characterization of transient protein-protein interface interactions.

Structural basis for the hydrolytic activity of the transpeptidase-like protein DpaA to detach Braun's lipoprotein from peptidoglycan.

IMPORTANCE: Cross-linking reaction of Braun's lipoprotein (Lpp) to peptidoglycan (PG) is catalyzed by some members of the YkuD family of transpeptidases. However, the exact opposite reaction of cleaving the Lpp-PG cross-link is performed by DpaA, which is also a YkuD-like protein. In this work, we determined the crystal structure of DpaA to provide the molecular rationale for the ability of the transpeptidase-like protein to cleave, rather than form, the Lpp-PG linkage. Our findings also revealed the structural features that distinguish the different functional types of the YkuD family enzymes from one another.

PAICS ubiquitination recruits UBAP2 to trigger phase separation for purinosome assembly.

Purinosomes serve as metabolons to enhance de novo purine synthesis (DNPS) efficiency through compartmentalizing DNPS enzymes during stressed conditions. However, the mechanism underpinning purinosome assembly and its pathophysiological functions remains elusive. Here, we show that K6-polyubiquitination of the DNPS enzyme phosphoribosylaminoimidazole carboxylase and phosphoribosylaminoimidazolesuccinocarboxamide synthetase (PAICS) by cullin-5/ankyrin repeat and SOCS box containing 11 (Cul5/ASB11)-based ubiquitin ligase plays a driving role in purinosome assembly. Upon several purinosome-inducing cues, ASB11 is upregulated by relieving the H3K9me3/HP1α-mediated transcriptional silencing, thus stimulating PAICS polyubiquitination. The polyubiquitinated PAICS recruits ubiquitin-associated protein 2 (UBAP2), a ubiquitin-binding protein with multiple stretches of intrinsically disordered regions, thereby inducing phase separation to trigger purinosome assembly for enhancing DNPS pathway flux. In human melanoma, ASB11 is highly expressed to facilitate a constitutive purinosome formation to which melanoma cells are addicted for supporting their proliferation, viability, and tumorigenesis in a xenograft model. Our study identifies a driving mechanism for purinosome assembly in response to cellular stresses and uncovers the impact of purinosome formation on human malignancies.

Structural basis for calcium-stimulating pore formation of Vibrio α-hemolysin.

Vibrio α-hemolysins (αHLs) are ß-pore-forming toxins secreted by Vibrio pathogens, crucial for the facilitation of bacterial infections through host cell lysis. These toxins are produced as inactive precursors, requiring proteolytic maturation and membrane association for activation within host tissues. Here, we investigate Vibrio campbellii αHL (VcαHL), and establish that its hemolytic activity is significantly stimulated by calcium ions, with an EC50 that aligns with physiological calcium concentrations. Furthermore, we illustrate the vital contribution of calcium ions to the oligomerization of VcαHL on membranes. Using X-ray crystallography and cryo-electron microscopy, we decipher both the immature and assembled structures of VcαHL and elucidate the conformational changes corresponding to toxin assembly. We also identify a calcium-binding module that is integral for VcαHL's calcium-dependent activation. These findings provide insights into the regulatory mechanisms of VcαHL and have the potential to inform the development of targeted therapeutic strategies against Vibrio infections.

Visualizing the membrane disruption action of antimicrobial peptides by cryo-electron tomography.

The abuse of antibiotics has led to the emergence of multidrug-resistant microbial pathogens, presenting a pressing challenge in global healthcare. Membrane-disrupting antimicrobial peptides (AMPs) combat so-called superbugs via mechanisms different than conventional antibiotics and have good application prospects in medicine, agriculture, and the food industry. However, the mechanism-of-action of AMPs has not been fully characterized at the cellular level due to a lack of high-resolution imaging technologies that can capture cellular-membrane disruption events in the hydrated state. Previously, we reported PepD2M, a de novo-designed AMP with potent and wide-spectrum bactericidal and fungicidal activity. In this study, we use cryo-electron tomography (cryo-ET) and high-speed atomic force microscopy (HS-AFM) to directly visualize the pepD2M-induced disruption of the outer and inner membranes of the Gram-negative bacterium Escherichia coli, and compared with a well-known pore-forming peptide, melittin. Our high-resolution cryo-ET images reveal how pepD2M disrupts the E. coli membrane using a carpet/detergent-like mechanism. Our studies reveal the direct membrane-disrupting consequence of AMPs on the bacterial membrane by cryo-ET, and this information provides critical insights into the mechanisms of this class of antimicrobial agents.

Validation of the Malay version of the Life Events Checklist for DSM-5 among Malaysian undergraduates.

This cross-sectional study aimed to validate the Life Events Checklist for DSM-5 (LEC-5) among Malaysian undergraduates (N = 500; mean age = 21.66 ± 1.57), of which 90.4% had ever experienced a lifetime traumatic event. Cronbach's alpha of .87 (95% CI [.86, .89]) and McDonald's omega of .89 (95% CI [.89, .93]) indicated good reliability. Confirmatory factor analysis based on a six-factor structure showed the best fit. The measurement invariance showed that the six-factor structure was similar across sexes. Therefore, the Malay LEC-5 is a valid and reliable instrument to screen for traumatic events among Malaysian undergraduates.

A RAD51-ADP double filament structure unveils the mechanism of filament dynamics in homologous recombination.

ATP-dependent RAD51 recombinases play an essential role in eukaryotic homologous recombination by catalyzing a four-step process: 1) formation of a RAD51 single-filament assembly on ssDNA in the presence of ATP, 2) complementary DNA strand-exchange, 3) ATP hydrolysis transforming the RAD51 filament into an ADP-bound disassembly-competent state, and 4) RAD51 disassembly to provide access for DNA repairing enzymes. Of these steps, filament dynamics between the ATP- and ADP-bound states, and the RAD51 disassembly mechanism, are poorly understood due to the lack of near-atomic-resolution information of the ADP-bound RAD51-DNA filament structure. We report the cryo-EM structure of ADP-bound RAD51-DNA filaments at 3.1 Å resolution, revealing a unique RAD51 double-filament that wraps around ssDNA. Structural analysis, supported by ATP-chase and time-resolved cryo-EM experiments, reveals a collapsing mechanism involving two four-protomer movements along ssDNA for mechanical transition between RAD51 single- and double-filament without RAD51 dissociation. This mechanism enables elastic change of RAD51 filament length during structural transitions between ATP- and ADP-states.