Elucidating the molecular mechanisms of regulation of cellular stress sensors

对压力的反应是有机体生理学和生物学的一个组成部分。在生存的进化斗争中，对压力条件的适应是一个决定性的优势。内质网（endoplasmic reticulum，ER）是位于细胞内的一个重要细胞器，具有蛋白质和脂质的合成、折叠、钙离子的储存和释放等功能。由许多内在或外在因素引起的ER功能的破坏在ER应激中达到高潮，并且ER产生应对反应[例如，未折叠蛋白反应（UPR）]以减轻或消除应激。UPR途径感知ER干扰，并涉及旨在重建蛋白质合成机制的不同组分，包括翻译衰减、编码伴侣蛋白和ER相关降解组分的基因的转录激活以及凋亡和自噬途径的激活。有三种ER跨膜应激传感器，包括对ER应激的UPR反应：PERK，ATF 6和IRE 1，具有管腔应激传感结构域的整合ER蛋白。我们的研究项目集中在确定参与细胞应激传感器调节的分子机制。 这项研究的长期目标是产生有关压力传感器的分子机制的基础知识，并为从事该计划的HQP提供独特的培训机会。通过ER腔环境调节UPR的腔传感器结构域仍然知之甚少。该研究计划于2014年启动，旨在解决这一知识差距。我们发现，ER驻留蛋白（氧化还原酶，环氧合酶和钙螯合蛋白）结合到IRE的ER腔应激传感结构域，影响其细胞信号转导。然而，控制这些相互作用的分子机制尚不清楚。此外，其他ER压力传感器的调节仍有待研究。为了解决这些问题，我们的研究计划有三个主题，重点是在相关ER驻留蛋白的存在下，使用重组IRE 1，PERK和ATF 6管腔结构域在体外重建机械事件;并评估ER管腔环境是否参与这一过程。 主题1.确定ER管腔应力传感器的性质 主题2.检查PERK和ATF 6 ER应力传感器的分子调节 主题3.确定ER应力传感器调节的生物学重要性 这项研究计划将产生新的见解ER压力传感器生物学，分子相互作用在压力传感的重要性，以及推进我们的ER压力应对反应的一般理解。我们还为HQP提供行业和学术工作部门所需的技术和技能培训提供良好的环境。我们成功的长期指标将是学员达到高级，有影响力的职位，如学术研究人员，行业领导者或政府决策者的百分比。

Responses to stress are an integral part of organism's physiology and biology. Adaptation to stressful conditions is a decisive advantage in the evolutionary struggle for existence. The endoplasmic reticulum (ER) is a centrally located intracellular organelle responsible for many housekeeping functions including the synthesis, folding of proteins and lipids, the storage and release of intracellular calcium. Disruption of ER function caused by many intrinsic or extrinsic factors culminates in ER stress, and the ER mounts a coping response [e.g., unfolded protein response (UPR)] to mitigate or eliminate the stress. The UPR pathways sense ER disturbance and involves distinct components designed to re-establish the protein synthetic machinery, including translational attenuation, transcriptional activation of genes encoding chaperones and components of the ER-associated degradation, and activation of apoptotic and autophagy pathways. There are three ER transmembrane stress sensors that comprise the UPR reaction to ER stress: PERK, ATF6, and IRE1, integral ER proteins with luminal stress sensing domains. Our research program is focused on identifying the molecular mechanisms involved in the regulation of cellular stress sensors. Long-term objectives of this research are to generate fundamental knowledge regarding molecular mechanisms of stress sensors and to provide unique training opportunity for HQP engaged in the program. Regulation of the luminal sensor domain of UPR by the ER luminal environment remains poorly understood. This research program was initiated in 2014 to address this knowledge gap. We discovered that ER resident proteins (oxidoreductase, cyclooxygenase and calsequestrin) bind to ER luminal stress sensing domain of IRE to affect its cellular signaling. However, the molecular mechanisms governing these interactions are not known. Furthermore, regulation of other ER stress sensors remains to be examined. To address these our research program has three themes focused on reconstituting the mechanistic events in vitro, using recombinant IRE1, PERK and ATF6 luminal domain, in the presence of relevant ER resident proteins; and assessing whether ER luminal environment is involved in this process. Theme 1. Determine the nature of ER luminal stress sensors Theme 2. Examine molecular regulation of PERK and ATF6 ER stress sensors Theme 3. Determine biological importance of ER stress sensors regulation This research program will yield new insights on ER stress sensors biology, the importance of molecular interaction in stress sensing, as well as advance our general understanding of ER stress coping responses. We also provide outstanding environment for training of HQP in technologies and skills desired by industry and academic job sectors. Longer-term indicators of our success will be percentages of trainees reaching senior, influential positions as academic researchers, industry leaders or government policy makers.