Chloroplast Ribosome Biogenesis Factors.

The formation of chloroplasts can be traced back to an ancient event in which a eukaryotic host cell containing mitochondria ingested a cyanobacterium. Since then, chloroplasts have retained many characteristics of their bacterial ancestor, including their transcription and translation machinery. In this review, recent research on the maturation of rRNA and ribosome assembly in chloroplasts is explored, along with their crucial role in plant survival and their implications for plant acclimation to changing environments. A comparison is made between the ribosome composition and auxiliary factors of ancient and modern chloroplasts, providing insights into the evolution of ribosome assembly factors. Although the chloroplast contains ancient proteins with conserved functions in ribosome assembly, newly evolved factors have also emerged to help plants acclimate to changes in their environment and internal signals. Overall, this review offers a comprehensive analysis of the molecular mechanisms underlying chloroplast ribosome assembly and highlights the importance of this process in plant survival, acclimation, and adaptation.

The plant cytosolic m6A RNA methylome stabilizes photosynthesis in the cold.

The sessile lifestyle of plants requires an immediate response to environmental stressors that affect photosynthesis, growth, and crop yield. Here, we showed that three abiotic perturbations-heat, cold, and high light-triggered considerable changes in the expression signatures of 42 epitranscriptomic factors (writers, erasers, and readers) with putative chloroplast-associated functions that formed clusters of commonly expressed genes in Arabidopsis. The expression changes under all conditions were reversible upon deacclimation, identifying epitranscriptomic players as modulators in acclimation processes. Chloroplast dysfunctions, particularly those induced by the oxidative stress-inducing norflurazon in a largely GENOME UNCOUPLED-independent manner, triggered retrograde signals to remodel chloroplast-associated epitranscriptomic expression patterns. N6-methyladenosine (m6A) is known as the most prevalent RNA modification and impacts numerous developmental and physiological functions in living organisms. During cold treatment, expression of components of the primary nuclear m6A methyltransferase complex was upregulated, accompanied by a significant increase in cellular m6A mRNA marks. In the cold, the presence of FIP37, a core component of the writer complex, played an important role in positive regulation of thylakoid structure, photosynthetic functions, and accumulation of photosystem I, the Cytb6f complex, cyclic electron transport proteins, and Curvature Thylakoid1 but not that of photosystem II components and the chloroplast ATP synthase. Downregulation of FIP37 affected abundance, polysomal loading, and translation of cytosolic transcripts related to photosynthesis in the cold, suggesting m6A-dependent translational regulation of chloroplast functions. In summary, we identified multifaceted roles of the cellular m6A RNA methylome in coping with cold; these were predominantly associated with chloroplasts and served to stabilize photosynthesis.

Evidence-based Shared-Decision-Making Assistant (SDM-assistant) for choosing antipsychotics: protocol of a cluster-randomized trial in hospitalized patients with schizophrenia.

BACKGROUND: Choosing an antipsychotic medication is an important medical decision in the treatment of schizophrenia. This decision requires risk-benefit assessments of antipsychotics, and thus, shared-decision making between physician and patients is strongly encouraged. Although the efficacy and side-effect profiles of antipsychotics are well-established, there is no clear framework for the communication of the evidence between physicians and patients. For this reason, we developed an evidence-based shared-decision making assistant (SDM-assistant) that presents high-quality evidence from network meta-analysis on the efficacy and side-effect profile of antipsychotics and can be used as a basis for shared-decision making between physicians and patients when selecting antipsychotic medications. METHODS: The planned matched-pair cluster-randomised trial will be conducted in acute psychiatric wards (n = 14 wards planned) and will include adult inpatients with schizophrenia or schizophrenia-like disorders (N = 252 participants planned). On the intervention wards, patients and their treating physicians will use the SDM-assistant, whenever a decision on choosing an antipsychotic is warranted. On the control wards, antipsychotics will be chosen according to treatment-as-usual. The primary outcome will be patients' perceived involvement in the decision-making during the inpatient stay as measured with the SDM-Q-9. We will also assess therapeutic alliance, symptom severity, side-effects, treatment satisfaction, adherence, quality of life, functioning and rehospitalizations as secondary outcomes. Outcomes could be analysed at discharge and at follow-up after three months from discharge. The analysis will be conducted per-protocol using mixed-effects linear regression models for continuous outcomes and logistic regression models using generalised estimating equations for dichotomous outcomes. Barriers and facilitators in the implementation of the intervention will also be examined using a qualitative content analysis. DISCUSSION: This is the first trial to examine a decision assistant specifically designed to facilitate shared-decision making for choosing antipsychotic medications, i.e., SDM-assistant, in acutely ill inpatients with schizophrenia. If the intervention can be successfully implemented, SDM-assistant could advance evidence-based medicine in schizophrenia by putting medical evidence on antipsychotics into the context of patient preferences and values. This could subsequently lead to a higher involvement of the patients in decision-making and better therapy decisions. TRIAL REGISTRATION: German Clinical Trials Register (ID: DRKS00027316 , registration date 26.01.2022).

COVID-19 pandemic and impact on cancer clinical trials: An academic medical center perspective.

The COVID-19 pandemic changed health-care operations around the world and has interrupted standard clinical practices as well as created clinical research challenges for cancer patients. Cancer patients are uniquely susceptible to COVID-19 infection and have some of the worst outcomes. Importantly, cancer therapeutics could potentially render cancer patients more susceptible to demise from COVID-19 yet the poor survival outcome of many cancer diagnoses outweighs this risk. In addition, the pandemic has resulted in risks to health-care workers and research staff driving important change in clinical research operations and procedures. Remote telephone and video visits, remote monitoring, electronic capture of signatures and data, and limiting sample collections have allowed the leadership in our institution to ensure the safety of our staff and patients while continuing critical clinical research operations. Here we discuss some of these unique challenges and our response to change that was necessary to continue cancer clinical research; and, the impacts the pandemic has caused including increases in efficiency for our cancer research office.

PUMPKIN, the Sole Plastid UMP Kinase, Associates with Group II Introns and Alters Their Metabolism.

The chloroplast hosts photosynthesis and a variety of metabolic pathways that are essential for plant viability and acclimation processes. In this study, we show that the sole plastid UMP kinase (PUMPKIN) in Arabidopsis (Arabidopsis thaliana) associates specifically with the introns of the plastid transcripts trnG-UCC, trnV-UAC, petB, petD, and ndhA in vivo, as revealed by RNA immunoprecipitation coupled with deep sequencing (RIP-Seq); and that PUMPKIN can bind RNA efficiently in vitro. Analyses of target transcripts showed that PUMPKIN affects their metabolism. Null alleles and knockdowns of pumpkin were viable but clearly affected in growth, plastid translation, and photosynthetic performance. In pumpkin mutants, the levels of many plastid transcripts were reduced, while the amounts of others were increased, as revealed by RNA-Seq analysis. PUMPKIN is a homomultimeric, plastid-localized protein that forms in vivo RNA-containing megadalton-sized complexes and catalyzes the ATP-dependent conversion of UMP to UDP in vitro with properties characteristic of known essential eubacterial UMP kinases. A moonlighting function of PUMPKIN combining RNA and pyrimidine metabolism is discussed.

RNA-stabilization factors in chloroplasts of vascular plants.

In contrast to the cyanobacterial ancestor, chloroplast gene expression is predominantly governed on the post-transcriptional level such as modifications of the RNA sequence, decay rates, exo- and endonucleolytic processing as well as translational events. The concerted function of numerous chloroplast RNA-binding proteins plays a fundamental and often essential role in all these processes but our understanding of their impact in regulation of RNA degradation is only at the beginning. Moreover, metabolic processes and post-translational modifications are thought to affect the function of RNA protectors. These protectors contain a variety of different RNA-recognition motifs, which often appear as multiple repeats. They are required for normal plant growth and development as well as diverse stress responses and acclimation processes. Interestingly, most of the protectors are plant specific which reflects a fast-evolving RNA metabolism in chloroplasts congruent with the diverging RNA targets. Here, we mainly focused on the characteristics of known chloroplast RNA-binding proteins that protect exonuclease-sensitive sites in chloroplasts of vascular plants.

PALE CRESS binds to plastid RNAs and facilitates the biogenesis of the 50S ribosomal subunit.

The plant-specific PALE CRESS (PAC) protein has previously been shown to be essential for photoautotrophic growth. Here we further investigated the molecular function of the PAC protein. PAC localizes to plastid nucleoids and forms large proteinaceous and RNA-containing megadalton complexes. It co-immunoprecipitates with a specific subset of chloroplast RNAs including psbK-psbI, ndhF, ndhD, and 23S ribosomal RNA (rRNA), as demonstrated by RNA immunoprecipitation in combination with high throughput RNA sequencing (RIP-seq) analyses. Furthermore, it co-migrates with premature 50S ribosomal particles and specifically binds to 23S rRNA in vitro. This coincides with severely reduced levels of 23S rRNA in pac leading to translational deficiencies and related alterations of plastid transcript patterns and abundance similar to plants treated with the translation inhibitor lincomycin. Thus, we conclude that deficiency in plastid ribosomes accounts for the pac phenotype. Moreover, the absence or reduction of PAC levels in the corresponding mutants induces structural changes of the 23S rRNA, as demonstrated by in vivo RNA structure probing. Our results indicate that PAC binds to the 23S rRNA to promote the biogenesis of the 50S subunit.

Community-based, acute posttraumatic stress management: a description and evaluation of a psychosocial-intervention continuum.

Much of today's psychological trauma can be identified as resulting from sudden and seemingly random events, and particularly from events that involve the loss of human life. This article presents a perspective on how behavioral health providers may approach the design, development, and implementation of community-based psychological trauma interventions. These interventions allow those community members most affected by the trauma to play a central role in the resolution of, and community adaptation to, traumatic losses. After a brief discussion of "critical incident stress debriefing"--a common form of psychological "first aid" that is sometimes used following traumatic events that affect a community--the article turns to the description of a community-based trauma-response program that provides a continuum-of-care model for the care and management of individual and group reactions to shared, traumatic events. A recent evaluation of that program, which was developed by the Community Services Program of the Trauma Center in Boston, is presented as an important first step toward determining the types of community-based responses that show promise in our efforts to ameliorate the impact of traumatic events in communities nationwide and internationally.