REGULATION OF SECRETORY & MEMBRANE PROTEIN BIOGENESIS

我们的实验室感兴趣的是新生分泌和膜蛋白通过内质网膜转移或整合到内质网膜、适当修饰、折叠和组装的机制，然后再转移到细胞的不同部分。一个在很大程度上未被探索的概念是，易位的某些方面可以被调节，或者在疾病的发病机制中被错误调节。在缺乏对所涉基本进程的机械性理解的情况下，很难探讨这一概念。随着最近对简单分泌蛋白易位的深入了解，现在的阶段是询问更复杂的底物是否可以在其生物发生的某些方面受到调节。因此，我们实验室的长期目标是揭示分泌和膜蛋白作为细胞中一个新的调节部位的生物发生，确定涉及的调节机制和因素，并确定这种调节在细胞生物学和疾病发病机制中的作用。我们正在采取两种方法来实现这些目标。首先，我们正在使用体外生化系统来重建和研究与医学相关的分泌和膜蛋白生物发生的关键步骤。对扰动特别敏感或被确定为改变与疾病相关的突变体的步骤将进一步剖析。从这些生化研究中获得的见解和工具被用来开发关于与所研究的底物相关的疾病的病理生理学的具体的可测试假说。这些假说通过包括培养细胞和转基因小鼠在内的体内模型系统进行了检验。目前，实验室正在研究的蛋白质包括Prion蛋白和血管紧张素原，它们分别与神经退行性疾病和高血压有关。据设想，这些模型底物的洞察力将揭示一个对生理学和疾病具有直接影响的极其复杂的调节点。

Our laboratory is interested in the mechanisms by which nascent secretory and membrane proteins are translocated across or integrated into the endoplasmic reticulum membrane, appropriately modified, folded, and assembled prior to subsequent transit to various parts of the cell. One largely unexplored concept is the idea that certain aspects of translocation can be regulated, or misregulated in the pathogenesis of disease. This notion has been difficult to explore in the absence of a mechanistic understanding of the basic processes involved. With the recent insights into simple secretory protein translocation, the stage is now set to ask whether more complex substrates can be subject to regulation in some aspect of their biogenesis. Thus, the long term objectives of our laboratory are to reveal the biogenesis of secretory and membrane proteins as a novel site of regulation in the cell, identify the regulatory mechanisms and factors involved, and define roles for this type of regulation in cell biology and disease pathogenesis. We are taking two approaches to achieving these objectives. First, we are using an in vitro biochemical system to reconstitute and study key steps in the biogenesis of medically relevant secretory and membrane proteins. Steps that are particularly sensitive to perturbation or are determined to be altered for disease-associated mutants are dissected further. Insights and tools gained from these biochemical studies are used to develop specific testable hypotheses on the pathophysiology of diseases associated with the substrates under study. These hypotheses are tested using in vivo model systems including cultured cells and transgenic mice. At present, proteins under study in the laboratory include the prion protein and angiotensinogen, which are involved in neurodegenerative disease and hypertension, respectively. It is envisioned that the insights from these model substrates will reveal a richly complex point of regulation that has direct implications for physiology and disease.