Target of rapamycin (TOR) kinase is a sensor and a central integrator of internal and external metabolic cues. However, in algae and in higher plants, the components of TOR kinase signaling are yet to be characterized. Here, we establish an assay system to study TOR kinase activity in Chlamydomonas reinhardtii using the phosphorylation status of its putative downstream target, CrS6K. Using this assay, we probe the modulation of cellular TOR kinase activity under various physiological states such as photoautotrophy, heterotrophy, mixotrophy, and nitrogen (N) starvation. Importantly, we uncover that excess acetate in the medium leads to high cellular reactive oxygen species levels, triggering autophagy and a concomitant drop in TOR kinase activity in a dose-dependent manner, thus leading to a N-starvationlike cellular phenotype, even when nitrogen is present.

Background: Competence by design (CBD) is a nationally developed hybrid competency based medical education (CBME) curricular model that focuses on residents’ abilities to promote successful practice and better meet societal needs. CBD is based on a commonly used framework of five core components of CBME: outcome competencies, sequenced progression, tailored learning experiences, competency-focused instruction and programmatic assessment. There is limited literature concerning residents’ perceptions of implementation of CBME. Objective: We explored resident perceptions of this transformation and their views as they relate to the intended framework. Methods: We recruited residents enrolled in current CBME implementation between August 2018 and January 2019. We interviewed residents representing eight disciplines from the initial two CBME implementation cohorts. Inductive thematic analysis was used to analyse the data through iterative consensus building until saturation. Results: We identified five themes: 1) Value of feedback for residents; 2) Resident strategies for successful Entrustable Professional Activity observation completion; 3) Residents experience challenges; 4) Resident concerns regarding CBME; and 5) Resident recommendations to improve existing challenges. We found that while there was clear alignment with residents’ perceptions of the programmatic assessment core CBME component, alignment was not as clear for other components. Conclusions: Residents perceived aspects of this transformation as helpful but overall had mixed perceptions and variable understanding of the intended underlying framework. Understanding and disseminating successes and challenges from the resident lens may assist programs at different stages of CBME implementation.

While the role of TOR kinase in the chloroplast biogenesis and transcriptional regulation of photosynthesis is well documented in Arabidopsis, the functional relevance of this metabolic sensor kinase in chloroplast–mitochondria cross talk is unknown. Using Chlamydomonas reinhardtii as the model system, we demonstrate the role of TOR kinase in the regulation of chloroplast and mitochondrial functions: We show that TOR kinase inhibition impairs the maintenance of high ETR associated with PSII and low NPQ and inhibits efficient state transitions between PSII and PSI. While compromised photosynthetic functions are observed in TOR kinase inhibited cells, same conditions lead to augmentation in mitochondrial basal respiration rate by twofold and concomitantly a rise in ATP production. Interestingly, such upregulated mitochondrial functions in TOR‐inhibited cells are mediated by fragmented mitochondria via upregulating COXIIb and downregulating Hxk1 and AOX1 protein levels. We propose that TOR kinase may act as a sensor that counter‐regulates chloroplast versus mitochondrial functions in a normal C. reinhardtii cell.

Mitogen-activated protein kinase (MAPK) is an important mediator of cellular signaling pathways. In an attempt to investigate the role of these kinases in contact allergen/irritant-induced signaling cascades, we have utilized keratinocyte (A431 cell line) as antigen presenting cells (APCs). This group has previously reported the applicability of A431 as an APC. The role of these kinases in the elicitation pathways of allergic contact dermatitis was investigated using interleukin-12p40 (IL-12p40) as a marker. Inhibitors of the isoforms of MAPK reduced the allergen-induced IL-12 release in the A431 cell line. This result suggests a possible role of the isoforms of MAPK in the development of contact allergy.

Target Of Rapamycin (TOR) kinase is a sensor as well as a central integrator of internal and external metabolic cues. The upstream and downstream signals of this kinase are very well characterized in animals. However, in algae, higher plants and other photosynthetic organisms, the components of the TOR kinasesignaling are yet to be characterized. Here, we establish an assay system to study TOR kinase activity in C.reinhardtii using the phosphorylation status of its downstream target, CrS6K. We further use this assay to monitor TOR kinase activity under various physiological states such as photoautotrophy, heterotrophy, mixotrophy and nitrogen starvation. We observe that autotrophy in light (and not in dark) leads to TOR kinase attenuation during N starvation while the same is not observed in mixotrophy. Importantly, we show that the external carbon source glucose is sensed and uptaken by C.reinhardtii cells only in the presence of light and not in the dark. And such exogenously added glucose, as the photoassimilate carbon mimic, results in enhanced production of ROS, induction of autophagy and concomitant drop in TOR kinase activity, creating Nstarvation-like cellular state even in N+ conditions. Interestingly, dose dependent addition of glucose revealed TOR kinase activation in low glucose regime (ROS independent) followed by attenuation of TOR kinase (ROS dependent) at high glucose levels.