REGULATION OF SECRETORY & MEMBRANE PROTEIN BIOGENESIS

我们的实验室对新生分泌蛋白和膜蛋白在转运到细胞的各个部分之前通过内质网膜转运或整合到内质网膜上的机制感兴趣。一个很大程度上未被探索的概念是，在疾病的发病机制中，易位的某些方面可以被调节或被错误调节。在缺乏对所涉及的基本过程的机械理解的情况下，这个概念很难探索。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蛋白和膜蛋白作为细胞中一个新的调控位点的生物发生，确定所涉及的调控机制和因素，并确定这种调控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医学上相关的分泌蛋白和膜蛋白的生物发生的关键步骤。对扰动特别敏感或确定为疾病相关突变而改变的步骤进一步剖析。从这些生物化学研究中获得的见解和工具用于开发与所研究底物相关的疾病病理生理学的特定可测试假设。这些假设通过体内模型系统进行了验证，包括培养细胞和转基因小鼠。目前，实验室正在研究的蛋白质包括朊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，从这些模型底物的见解将揭示一个丰富复杂的调控点，对生理和疾病有直接的影响。

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.