Liguleless narrow and narrow odd dwarf act in overlapping pathways to regulate maize development and metabolism.

Narrow odd dwarf (nod) and Liguleless narrow (Lgn) are pleiotropic maize mutants that both encode plasma membrane proteins, cause similar developmental patterning defects, and constitutively induce stress signaling pathways. To investigate how these mutants coordinate maize development and physiology, we screened for protein interactors of NOD by affinity purification. LGN was identified by this screen as a strong candidate interactor, and we confirmed the NOD-LGN molecular interaction through orthogonal experiments. We further demonstrated that LGN, a receptor-like kinase, can phosphorylate NOD in vitro, hinting that they could act in intersecting signal transduction pathways. To test this hypothesis, we generated Lgn-R;nod mutants in two backgrounds (B73 and A619), and found that these mutations enhance each other, causing more severe developmental defects than either single mutation on its own, with phenotypes including very narrow leaves, increased tillering, and failure of the main shoot. Transcriptomic and metabolomic analyses of the single and double mutants in the two genetic backgrounds revealed widespread induction of pathogen defense genes and a shift in resource allocation away from primary metabolism in favor of specialized metabolism. These effects were similar in each single mutant and heightened in the double mutant, leading us to conclude that NOD and LGN act cumulatively in overlapping signaling pathways to coordinate growth-defense tradeoffs in maize.

The Second Site Modifier, Sympathy for the ligule, Encodes a Homolog of Arabidopsis ENHANCED DISEASE RESISTANCE4 and Rescues the Liguleless narrow Maize Mutant.

Liguleless narrow1 encodes a plasma membrane-localized receptor-like kinase required for normal development of maize (Zea mays) leaves, internodes, and inflorescences. The semidominant Lgn-R mutation lacks kinase activity, and phenotypic severity is dependent on inbred background. We created near isogenic lines and assayed the phenotype in multiple environments. Lgn-R plants that carry the B73 version of Sympathy for the ligule (Sol-B) fail to grow under hot conditions, but those that carry the Mo17 version (Sol-M) survive at hot temperatures and are significantly taller at cool temperatures. To identify Sol, we used recombinant mapping and analyzed the Lgn-R phenotype in additional inbred backgrounds. We identified amino acid sequence variations in GRMZM2G075262 that segregate with severity of the Lgn-R phenotypes. This gene is expressed at high levels in Lgn-R B73, but expression drops to nonmutant levels with one copy of Sol-M An EMS mutation solidified the identity of SOL as a maize homolog of Arabidopsis (Arabidopsis thaliana) ENHANCED DISEASE RESISTANCE4 (EDR4). SOL, like EDR4, is induced in response to pathogen-associated molecular patterns such as flg22. Integrated transcriptomic and phosphoproteomic analyses suggest that Lgn-R plants constitutively activate an immune signaling cascade that induces temperature-sensitive responses in addition to defects in leaf development. We propose that aspects of the severe Lgn-R developmental phenotype result from constitutive defense induction and that SOL potentially functions in repressing this response in Mo17 but not B73. Identification of LGN and its interaction with SOL provides insight into the integration of developmental control and immune responses.

Drosophila emerins control LINC complex localization and transcription to regulate myonuclear position.

Mispositioned nuclei are a hallmark of skeletal muscle disease. Many of the genes that are linked to Emery-Dreifuss muscular dystrophy (EDMD) encode proteins that are critical for nuclear movement in various cells, suggesting that disruptions in nuclear movement and position may contribute to disease progression. However, how these genes are coordinated to move nuclei is not known. Here, we focussed on two different emerin proteins in Drosophila, Bocksbeutel and Otefin, and their effects on nuclear movement. Although nuclear position was dependent on both, elimination of either Bocksbeutel or Otefin produced distinct phenotypes that were based in differential effects on the KASH-domain protein Klarsicht. Specifically, loss of Bocksbeutel reduced Klarsicht localization to the nucleus and resulted in a disruption in nuclear separation. Loss of Otefin increased the transcription of Klarsicht and led to premature separation of nuclei and their positioning closer to the edge of the muscle. Consistent with opposing functions, nuclear position is normal in otefin; bocksbeutel double mutants. These data indicate emerin-dependent regulation of Klarsicht levels in the nuclear envelope is a critical determinant of nuclear position.

Arg-513 and Leu-531 Are Key Residues Governing Time-Dependent Inhibition of Cyclooxygenase-2 by Aspirin and Celebrex.

Aspirin and Celebrex are well-known time-dependent inhibitors of the cyclooxygenases (COX). Molecular dynamics simulations suggest that Arg-513 and Leu-531 contribute to the structural mechanisms of COX inhibition. We used mutagenesis and functional analyses to characterize how substitutions at these positions influence time-dependent inhibition by aspirin and Celebrex. We show that substitutions of Leu-531 with asparagine and phenylalanine significantly attenuate time-dependent inhibition of COX-2 by these drugs. The introduction of side chain bulk, rigidity, and charge would disrupt the formation of the initial noncovalent complex, in the case of aspirin, and the "high-affinity" binding state, in the case of Celebrex. Substitution of Arg-513 with histidine (the equivalent residue in COX-1) resulted in a 2-fold potentiation of aspirin inhibition, in support of the hypothesis that the presence of histidine in COX-1 lowers the activation barrier associated with the formation of the initial noncovalent enzyme-inhibitor complex. As a corollary, we previously hypothesized that the flexibility associated with Leu-531 contributes to the binding of arachidonic acid (AA) to acetylated COX-2 to generate 15R-hydroxyeicosatetraenoic acid (15R-HETE). We determined the X-ray crystal structure of AA bound to Co3+-protoporphyrin IX-reconstituted V349I murine COX-2 (muCOX-2). V349I muCOX-2 was utilized as a surrogate to trap AA in a conformation leading to 15R-HETE. AA binds in a C-shaped pose, facilitated by the rotation of the Leu-531 side chain. Ile-349 is positioned to sterically shield antarafacial oxygen addition at carbon-15 in a manner similar to that proposed for the acetylated Ser-530 side chain.

Virtual Program Delivery: Learning Through Extension Nutrition Educators' Experiences During the COVID-19 Pandemic.

OBJECTIVE: To describe and analyze how Extension nutrition educators in one state system transitioned from primarily face-to-face to virtual nutrition education programming. DESIGN: This exploratory case study gathered data through nutrition educator interviews, virtual program delivery guides, and nutrition educators' program impact statements. SETTING: Southeastern State Extension system in late 2022. PARTICIPANTS: The sample included 15 participant interviews, multiple virtual program delivery guides, and 43 program impact summaries. PHENOMENON OF INTEREST: The use of Cultural Historical Activity Theory as a framework to explore educators' learning process with virtual program delivery and how this learning influenced community nutrition program delivery choices. ANALYSIS: Qualitative data was analyzed with ATLAS.ti using a priori coding. RESULTS: Two key findings emerged from the data: educators were more likely to deliver programs in a virtual setting when the programs aligned with their values and skills, and educators preferred flexible program curricula and delivery guides because it allowed them to address their community's specific needs. CONCLUSIONS AND IMPLICATIONS: Educators plan to continue to deliver certain community nutrition programs virtually. Future research is needed to explore additional perspectives on virtual delivery, such as program participants and state program managers.

Mapping the architecture of the initiating phosphoglycosyl transferase from S. enterica O-antigen biosynthesis in a liponanoparticle.

Bacterial cell surface glycoconjugates are critical for cell survival and for interactions between bacteria and their hosts. Consequently, the pathways responsible for their biosynthesis have untapped potential as therapeutic targets. The localization of many glycoconjugate biosynthesis enzymes to the membrane represents a significant challenge for expressing, purifying, and characterizing these enzymes. Here, we leverage cutting-edge detergent-free methods to stabilize, purify, and structurally characterize WbaP, a phosphoglycosyl transferase (PGT) from the Salmonella enterica (LT2) O-antigen biosynthesis. From a functional perspective, these studies establish WbaP as a homodimer, reveal the structural elements responsible for dimerization, shed light on the regulatory role of a domain of unknown function embedded within WbaP, and identify conserved structural motifs between PGTs and functionally unrelated UDP-sugar dehydratases. From a technological perspective, the strategy developed here is generalizable and provides a toolkit for studying other classes of small membrane proteins embedded in liponanoparticles beyond PGTs.

Primary Care Residency Perspectives on Medical Student Performance Evaluations.

Introduction: With the transition of the United States Medical Licensing Examination (USMLE) Step 1 exam to pass-fail, residency directors are exploring alternative objective approaches when selecting candidates for interviews. The Medical Student Performance Evaluations (MSPE) portion of the application may be an area where objectivity could be provided. This study explored program directors' (PDs) perspectives on the utility of the MSPE as a discriminating factor for residency candidate selection. Methods: We invited PDs of primary care residencies listed in the American Medical Association FRIEDA database to participate in a mixed-methods study assessing opinions on the MSPE, and the importance of student skills and application components when considering a candidate for interview. We obtained summary statistics for Likert-scale responses. We used inductive thematic analysis to generate themes from open-ended comments. Results: Two hundred forty-nine PDs completed the survey (response rate=15.9%). Patient communication (83.6%) and teamwork (81.9%) were rated as very/extremely important skills, and being a graduate of a US medical school in the past 3 years (73.1%), no failures on board exams (58.2%), and MSPEs (54.8%) were rated as very/extremely important application components. Six hundred seventy-eight open-ended comments yielded themes related to desire for more transparency and standardization, importance of student attributes and activities, and other important components of applications. Conclusion: PDs place a high value on the MSPE but find it limited by concerns over validity, objectivity, and lack of standardization. The quality of MSPEs may be improved by using a common language of skill attainment such as the Association of American Medical Colleges' Entrustable Professional Activities and using the document to discuss students' other attributes and contributions.

Co-conserved sequence motifs are predictive of substrate specificity in a family of monotopic phosphoglycosyl transferases.

Monotopic phosphoglycosyl transferases (monoPGTs) are an expansive superfamily of enzymes that catalyze the first membrane-committed step in the biosynthesis of bacterial glycoconjugates. MonoPGTs show a strong preference for their cognate nucleotide diphospho-sugar (NDP-sugar) substrates. However, despite extensive characterization of the monoPGT superfamily through previous development of a sequence similarity network comprising >38,000 nonredundant sequences, the connection between monoPGT sequence and NDP-sugar substrate specificity has remained elusive. In this work, we structurally characterize the C-terminus of a prototypic monoPGT for the first time and show that 19 C-terminal residues play a significant structural role in a subset of monoPGTs. This new structural information facilitated the identification of co-conserved sequence "fingerprints" that predict NDP-sugar substrate specificity for this subset of monoPGTs. A Hidden Markov model was generated that correctly assigned the substrate of previously unannotated monoPGTs. Together, these structural, sequence, and biochemical analyses have delivered new insight into the determinants guiding substrate specificity of monoPGTs and have provided a strategy for assigning the NDP-sugar substrate of a subset of enzymes in the superfamily that use UDP-di-N-acetyl bacillosamine. Moving forward, this approach may be applied to identify additional sequence motifs that serve as fingerprints for monoPGTs of differing UDP-sugar substrate specificity.

Mapping the architecture of the initiating phosphoglycosyl transferase from S. enterica O-antigen biosynthesis in a liponanoparticle.

Bacterial cell surface glycoconjugates are critical for cell survival and for interactions between bacteria and their hosts. Consequently, the pathways responsible for their biosynthesis have untapped potential as therapeutic targets. The localization of many glycoconjugate biosynthesis enzymes to the membrane represents a significant challenge for expressing, purifying, and characterizing these enzymes. Here, we leverage cutting-edge methods to stabilize, purify, and structurally characterize WbaP, a phosphoglycosyl transferase (PGT) from Salmonella enterica (LT2) O-antigen biosynthesis without detergent solubilization from the lipid bilayer. From a functional perspective, these studies establish WbaP as a homodimer, reveal the structural elements responsible for oligomerization, shed light on the regulatory role of a domain of unknown function embedded within WbaP, and identify conserved structural motifs between PGTs and functionally unrelated UDP-sugar dehydratases. From a technological perspective, the strategy developed here is generalizable and provides a toolkit for studying small membrane proteins embedded in liponanoparticles beyond PGTs.

Pharmacy-based methadone treatment in the US: views of pharmacists and opioid treatment program staff.

BACKGROUND: The US federal regulations allow pharmacy administration and dispensing of methadone for opioid use disorder (PADMOUD) to increase the capability of opioid treatment programs (OTPs) in providing methadone maintenance treatment (MMT) for opioid use disorder (OUD) as part of a medication unit. However, there is a lack of research data from both pharmacy and OTP staff to inform the implementation of PADMOUD. METHODS: Staff of a pharmacy (n = 8) and an OTP (n = 9) that participated in the first completed US trial on PADMOUD through electronic prescribing for methadone (parent study) were recruited to participate in this qualitative interview study to explore implementation-related factors for PADMOUD. Each interview was recorded and transcribed verbatim. NVivo was used to help identify themes of qualitative interview data. The Promoting Action on Research Implementation in Health Services (PARIHS) framework was used to guide the coding and interpretation of data. RESULTS: Six pharmacy staff and eight OTP staff (n = 14) completed the interview. Results based on PARIHS domains were summarized, including evidence, context, and facilitation domains. Participants perceived benefits of PADMOUD for patients, pharmacies, OTPs, and payers. PADMOUD was considered to increase access for stable patients, provide additional patient service opportunities and revenues for pharmacies/pharmacists, enhance the capability of OTPs to treat more new patients, and reduce patients' cost when receiving medication at a pharmacy relative to an OTP. Both pharmacy and OTP staff were perceived to be supportive of the implementation of PADMOUD. Pharmacy staff/pharmacists were perceived to need proper training on addiction and methadone as well as a protocol of PADMOUD to conduct PADMOUD. Facilitators include having thought leaders to guide the operation, a certification program to ensure proper training of pharmacy staff/pharmacist, having updated pharmacy service software or technology to streamline the workflow of delivering PADMOUD and inventory management, and reimbursement for pharmacists. CONCLUSION: This study presents the first findings on perspectives of PADMOUD from both staff of a community pharmacy and an OTP in the US. Finding on barriers and facilitators are useful data to guide the development of strategies to implement PADMOUD to help address the US opioid crisis.

Patient perspectives on community pharmacy administered and dispensing of methadone treatment for opioid use disorder: a qualitative study in the U.S.

BACKGROUND: Pharmacy administration and dispensing of methadone treatment for opioid use disorder (PADMOUD) may address inadequate capability of opioid treatment programs (OTPs) in the US by expanding access to methadone at community pharmacies nationally. PADMOUD is vastly underutilized in the US. There is no published US study on OUD patients' perspectives on PADMOUD. Data are timely and needed to inform the implementation of PADMOUD in the US to address its serious opioid overdose crisis. METHODS: Patient participants of the first completed US trial on PADMOUD through electronic prescribing for methadone (parent study) were interviewed to explore implementation-related factors for PADMOUD. All 20 participants of the parent study were invited to participate in this interview study. Each interview was recorded and transcribed verbatim. Thematic analysis was conducted to identify emergent themes. RESULTS: Seventeen participants completed the interview. Patients' perspectives on PADMOUD were grouped into five areas. Participants reported feasibility of taking the tablet formulation of methadone at the pharmacy and identified benefits from PADMOUD (e.g., better access, efficiency, convenience) compared with usual care at the OTP. Participants perceived support for PADMOUD from their family/friends, OTP staff, and pharmacy staff. PADMOUD was perceived to be a great option for stable patients with take-home doses and those with transportation barriers. The distance (convenience), office hours, and the cost were considered factors most influencing their decision to receive methadone from a pharmacy. Nonjudgmental communication, pharmacists' training on methadone treatment, selection of patients (stable status), workflow of PADMOUD, and protection of privacy were considered key factors for improving operations of PADMOUD. CONCLUSION: This study presents the first findings on patient perspectives on PADMOUD. Participants considered pharmacies more accessible than OTPs, which could encourage more people to receive methadone treatment earlier and help transition stable patients from an OTP into a local pharmacy. The findings have timely implications for informing implementation strategies of PADMOUD that consider patients' views and needs.

Scarecrow plays a role in establishing Kranz anatomy in maize leaves.

More than a quarter of the primary productivity on land, and a large fraction of the food that humans consume, is contributed by plants that fix atmospheric CO(2) by C(4) photosynthesis. It has been estimated that transferring the C(4) pathway to C(3) crops could boost yield by 50% and also increase water use efficiency and reduce the need for fertilizer, particularly in dry, hot environments. The high productivity of maize (Zea mays), sugarcane (Saccharum spp.) and several emerging bioenergy grasses is due largely to C(4) photosynthesis, which is enabled by the orderly arrangement, in concentric rings, of specialized bundle sheath and mesophyll cells in leaves in a pattern known as Kranz anatomy. Here we show that PIN, the auxin efflux protein, is present in the end walls of maize bundle sheath cells, as it is in the endodermis of the root. Since this marker suggests the expression of endodermal genetic programs in bundle sheath cells, we determined whether the transcription factor SCARECROW, which regulates structural differentiation of the root endodermis, also plays a role in the development of Kranz anatomy in maize. Mutations in the Scarecrow gene result in proliferation of bundle sheath cells, abnormal differentiation of bundle sheath chloroplasts, vein disorientation, loss of minor veins and reduction of vein density. Further characterization of this signal transduction pathway should facilitate the transfer of the C(4) trait into C(3) crop species, including rice.

Probing Monotopic Phosphoglycosyl Transferases from Complex Cellular Milieu.

Monotopic phosphoglycosyl transferase enzymes (monoPGTs) initiate the assembly of prokaryotic glycoconjugates essential for bacterial survival and proliferation. MonoPGTs belong to an expansive superfamily with a diverse and richly annotated sequence space; however, the biochemical roles of most monoPGTs in glycoconjugate biosynthesis pathways remain elusive. To better understand these critical enzymes, we have implemented activity-based protein profiling (ABPP) probes as protein-centric, membrane protein compatible tools that lay the groundwork for understanding the activity and regulation of the monoPGT superfamily from a cellular proteome. With straightforward gel-based readouts, we demonstrate robust, covalent labeling at the active site of various representative monoPGTs from cell membrane fractions using 3-phenyl-2H-azirine probes.

75-year-old woman • right-side rib pain • radiating shoulder pain • history of hypertension & hypercholesterolemia • Dx?

► Right-side rib pain ► Radiating shoulder pain ► History of hypertension & hypercholesterolemia.

Sleepiness, Exertion Fatigue, Arousal, and Vigilant Attention in Persons With Chronic Aphasia.

Purpose Individuals in the acute and chronic stages of stroke recovery often report more daytime sleepiness (Sterr, Herron, Dijk, & Ellis, 2008) and fatigue that qualitatively differs from "normal" feelings of fatigue they experienced prestroke (De Doncker, Dantzer, Ormstad, & Kuppuswamy, 2018). Speech-language pathologists frequently observe signs of fatigue in their clients with aphasia and perceive that client fatigue impedes therapeutic interventions (Riley, 2017). The current study aimed to quantify daytime sleepiness, exertion fatigue, and physiologically measured arousal and vigilant attention in persons with aphasia. Method We measured sleepiness, exertion fatigue, arousal, and vigilant attention in 10 participants with aphasia and 10 neurologically healthy adults. Daytime sleepiness was measured using the Epworth Sleepiness Scale (Johns, 1991). Exertion fatigue was measured using the Visual Analog Fatigue Scale (B. Y. Tseng, Gajewski, & Kluding, 2010) before and after a 72-min computer-administered language task. Arousal was measured using heart rate and variability (Shaffer & Ginsberg, 2017). Vigilant attention was measured using electroencephalography and subsequently classified into 1 of 4 levels of vigilant attention using a classification algorithm (Berka et al., 2004). Results Persons with aphasia did not show significant differences from controls in reported amount of daytime sleepiness, exertion fatigue, or overall physiological arousal but demonstrated different patterns of electroencephalography-measured vigilant attention and error production as compared to controls. Conclusions Although overall sleepiness, exertion fatigue, and overall arousal did not differ between groups, physiological measures of vigilant attention may be more sensitive to differences and may explain feelings of fatigue that persons with chronic aphasia experience.

Emery-Dreifuss muscular dystrophy-linked genes and centronuclear myopathy-linked genes regulate myonuclear movement by distinct mechanisms.

Muscle cells are a syncytium in which the many nuclei are positioned to maximize the distance between adjacent nuclei. Although mispositioned nuclei are correlated with many muscle disorders, it is not known whether this common phenotype is the result of a common mechanism. To answer this question, we disrupted the expression of genes linked to Emery-Dreifuss muscular dystrophy (EDMD) and centronuclear myopathy (CNM) in Drosophila and evaluated the position of the nuclei. We found that the genes linked to EDMD and CNM were each necessary to properly position nuclei. However, the specific phenotypes were different. EDMD-linked genes were necessary for the initial separation of nuclei into distinct clusters, suggesting that these factors relieve interactions between nuclei. CNM-linked genes were necessary to maintain the nuclei within clusters as they moved toward the muscle ends, suggesting that these factors were necessary to maintain interactions between nuclei. Together these data suggest that nuclear position is disrupted by distinct mechanisms in EDMD and CNM.

Use of Chironomidae (Diptera) Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies.

Rapid bioassessment protocols using benthic macroinvertebrate assemblages have been successfully used to assess human impacts on water quality. Unfortunately, traditional benthic larval sampling methods, such as the dip-net, can be time-consuming and expensive. An alternative protocol involves collection of Chironomidae surface-floating pupal exuviae (SFPE). Chironomidae is a species-rich family of flies (Diptera) whose immature stages typically occur in aquatic habitats. Adult chironomids emerge from the water, leaving their pupal skins, or exuviae, floating on the water's surface. Exuviae often accumulate along banks or behind obstructions by action of the wind or water current, where they can be collected to assess chironomid diversity and richness. Chironomids can be used as important biological indicators, since some species are more tolerant to pollution than others. Therefore, the relative abundance and species composition of collected SFPE reflect changes in water quality. Here, methods associated with field collection, laboratory processing, slide mounting, and identification of chironomid SFPE are described in detail. Advantages of the SFPE method include minimal disturbance at a sampling area, efficient and economical sample collection and laboratory processing, ease of identification, applicability in nearly all aquatic environments, and a potentially more sensitive measure of ecosystem stress. Limitations include the inability to determine larval microhabitat use and inability to identify pupal exuviae to species if they have not been associated with adult males.