Evolution and diversification of the plant gibberellin receptor GID1.

The plant gibberellin (GA) receptor GID1 shows sequence similarity to carboxylesterase (CXE). Here, we report the molecular evolution of GID1 from establishment to functionally diverse forms in eudicots. By introducing 18 mutagenized rice GID1s into a rice gid1 null mutant, we identified the amino acids crucial for GID1 activity in planta. We focused on two amino acids facing the C2/C3 positions of ent-gibberellane, not shared by lycophytes and euphyllophytes, and found that adjustment of these residues resulted in increased GID1 affinity toward GA4, new acceptance of GA1 and GA3 carrying C13-OH as bioactive ligands, and elimination of inactive GAs. These residues rendered the GA perception system more sophisticated. We conducted phylogenetic analysis of 169 GID1s from 66 plant species and found that, unlike other taxa, nearly all eudicots contain two types of GID1, named A- and B-type. Certain B-type GID1s showed a unique evolutionary characteristic of significantly higher nonsynonymous-to-synonymous divergence in the region determining GA4 affinity. Furthermore, these B-type GID1s were preferentially expressed in the roots of Arabidopsis, soybean, and lettuce and might be involved in root elongation without shoot elongation for adaptive growth under low-temperature stress. Based on these observations, we discuss the establishment and adaption of GID1s during plant evolution.

DELLA protein functions as a transcriptional activator through the DNA binding of the indeterminate domain family proteins.

DELLA protein is a key negative regulator of gibberellin (GA) signaling. Although how DELLA regulates downstream gene expression remains unclear, DELLA has been proposed to function as a transcriptional activator. However, because DELLA lacks a DNA-binding domain, intermediate protein(s) mediating the DELLA/DNA interaction are believed to be necessary for activating DELLA target genes. Here, using yeast hybrid screenings, we identified five members of indeterminate domain (IDD) protein family which bind physically to both DELLA and the promoter sequence of the GA-positive regulator SCARECROW-LIKE 3 (SCL3), which previously was characterized as a DELLA direct target gene. Transient assays using Arabidopsis protoplasts demonstrated that a luciferase reporter controlled by the SCL3 promoter was additively transactivated by REPRESSOR of ga1-3 (RGA) and IDDs. Phenotypic analysis of transgenic plants expressing AtIDD3 (one of the 16 IDDs in the Arabidopsis genome) fused with the plant-specific repression domain (SRDX) supported the possibility that AtIDD3 is positively involved in GA signaling. In addition, we found that SCL3 protein also interacts with IDDs, resulting in the suppression of its target gene expression. In this context, DELLA and SCL3 interact competitively with IDD proteins to regulate downstream gene expression. These results suggest that the coregulators DELLA and SCL3, using IDDs as transcriptional scaffolds for DNA binding, antagonistically regulate the expression of their downstream targets to control the GA signaling pathway.

Expression and purification of a GRAS domain of SLR1, the rice DELLA protein.

GRAS proteins belong to a plant specific protein family that participates in diverse and important functions in growth and development. GRAS proteins are typically composed of a variable N-terminal domain and highly conserved C-terminal GRAS domain. Despite the importance of the GRAS domain, little biochemical or structural analyses have been reported, mainly due to difficulties with purification of sufficient quality and quantity of protein. This study is focused on one of the most extensively studied GRAS proteins, the rice DELLA protein (SLR1), which is known to be involved in gibberellin (GA) signaling. Using a baculovirus-insect cell expression system we have achieved overproduction and purification of full-length SLR1. Limited proteolysis of the full-length SLR1 indicated that a region including the entire GRAS domain (SLR1(206-625)) is protease resistant. Based on those results, we have constructed an expression and purification system of the GRAS domain (SLR1(206-625)) in Escherichia coli. Several physicochemical assays have indicated that the folded structure of the GRAS domain is rich in secondary structural elements and that alanine substitutions for six cysteine residues improves protein folding without impairing function. Furthermore, by NMR spectroscopy we have observed direct interaction between the purified GRAS domain and the GA receptor GID1. Taken together, our purified preparation of the GRAS domain of SLR1 is suitable for further structural and functional studies that will contribute to precise understanding of the plant regulation mechanism through DELLA and GRAS proteins.

Opportunities for Interactive Communication in Mechanically Ventilated Critically Ill Patients: A Video-Based Observational Study.

Background: Mechanically ventilated critically ill patients need the opportunity to communicate their physical and psychosocial concerns to nurses. However, these patients face the unique problem of lacking even the opportunity to communicate. Aims: The study aimed to describe the characteristics of communication opportunities for critically ill mechanically ventilated patients. Methods: The study was designed as a video-based descriptive observational study. Participants included seven mechanically ventilated critically ill patients at the intensive care unit, coronary care unit, or high care unit who were conscious and seven registered nurses (seven pairs). Videos were recorded continuously from 8 am to 4 pm, and the footage was then descriptively analyzed. Data collection took place between July 2019 and June 2020. Results: The total recording time was 668.0 minutes. Of these 668.0 minutes, nurses stayed in the Conversation Area of the Patient for 279.6 minutes, and of these 279.6 minutes, two-way face-to-face communication between nurse and patient occurred for 78.0 minutes. Of these 78.0 minutes, communications were started by nurses for 47.2 minutes (174 scenes) and by patients for 24.2 minutes (36 scenes). The patient-started two-way communication scenes included 37 instances of Patient-Intentional-Action that triggered the start of communication. Actions using the upper limbs were observed in 20 instances and represented the most frequently used body part. The head/face, lower limbs, or trunk were also used in some of the actions. Gestures were the most commonly used action type (14 instances). Other types included lip movement, grimace, leg flex/extension, and cough. Conclusions: We found that nurses tended to start communication more frequently than patients did and that patients demonstrated Patient-Intentional-Action with a variety of actions using various body parts. Communication opportunities for patients were created when nurses took the initiative to start communication or when they noticed and responded to the Patient-Intentional-Action. Our findings demonstrate that nurses need to recognize and always respond to Patient-Intentional-Action and to take the initiative in communicating rather than waiting for the patient to do so.

Interprofessional Collaborative Practice for Child Maltreatment Prevention in Japan: A Literature Review.

This literature review explored the factors promoting interprofessional collaborative practice for the child maltreatment prevention in Japan. We searched the Japanese database of ICHUSHI-web, focusing on studies published between 1990 and 2015. The studies were examined for methodological quality using the critical appraisal checklists. We initially identified 161 articles and finally selected eight studies that met the selection criteria and were analyzed. The Collaborative Practice Circle based on the Interprofessional Education for Collaborative Patient-Centered Practice framework, was used as a conceptual framework to analyze the data and to discuss the review findings. Data analysis continued until categories were saturated using content analysis. Five categories as interactional factors, two categories as organizational factors and three categories as systemic factors were identified. The findings revealed that interactional factors were composed of practical competencies and experiences of professionals. Our findings also indicate that educational programs for improving practical competencies of professionals at the individual level and establishing a system of training and human resource development at the organizational level are required. Further research is warranted to examine the impact the challenges outlined in the interactional factors, the organizational interventions and support for clients.