Control of Protein Synthesis by the UPS Under Stress

项目摘要 这项建议是基于新发现的细胞应激反应的调节臂，其中Jun N- 末端激酶（JNK）被募集到翻译核糖体（多聚核糖体），以介导新的 合成蛋白（NSPs）。我们确定了这种新的调控模块对乳腺癌的重要性 (BCa)生物学，并确定泛素蛋白酶体系统（UPS）的组成部分，第一次， 国家安全机构的监控它们包括Cullin 2，Nedd 8和ubiquilin 1（UBQLN 1），我们证明了 来影响BCa细胞中的蛋白质合成。BCa中这些UPS成分的表达失调是BCa的基础 研究它们在BCa发育和对治疗反应中的作用的基本原理。 我们的初步结果支持了这样的假设，即控制NSP的稳定性构成了一个新的层， 调节蛋白质合成/可用性，这反过来又控制细胞对应激的反应。我们 进一步假设，这种调节对BCa的发展和对 疗法我们集中在几个互补的，但迄今尚未赞赏的机制，可能是NSP的基础 压力下的监视 Topisirovic博士、Sonenberg博士、米尔斯博士和Ronai博士之间富有成效的长期合作是 现在扩大到包括梅勒博士，从而使广泛的和互补的专业知识领域， 蛋白质合成和癌症生物学也包括纳米孔传感技术， 泛素链拓扑学。我们将共同评估新确定的特定NSP监管因素， 单独或协同调节细胞应激反应，特别是在BCa 发展和对治疗的反应。本研究的主要目的是：（1）建立一个生理 RACK 1-JNK-eEF 1A 2调节轴对细胞应激反应、生长和 乳腺癌的治疗反应。(2)评估应激诱导的多聚体募集的作用 Nedd 8-Cullin机制调节BCa中NSP的衰变。(3)确定的重要性 UBQLN 1在应激条件下对新合成蛋白质的调节中向多聚核糖体的募集 以及调节BCa对治疗的反应。 我们提出的研究将建立一个新的选择UPS组件的重要性和意义 在细胞应激期间控制蛋白质合成的调节网络，并使用 BCa培养物和异种移植物、RPPA技术和TCGA数据集挖掘的组合。

PROJECT SUMMARY This proposal is based on a newly discovered regulatory arm of the cellular stress response, whereby Jun N- terminal kinase (JNK) is recruited to translating ribosomes (polysomes) to mediate degradation of newly synthesized proteins (NSPs). We established the significance of this novel regulatory module to breast cancer (BCa) biology, and identify ubiquitin proteasome system (UPS) components that—for the first time—are linked with the surveillance of NSPs. They include Cullin 2, Nedd8, and ubiquilin1 (UBQLN1), which we demonstrate to impact protein synthesis in BCa cells. Dysregulated expression of these UPS components in BCa underlies the rationale for studying their role in BCa development and response to therapy. Our preliminary results support the hypothesis that control of NSP stability constitutes a novel layer of regulation of protein synthesis/availability, which in turn governs cellular responses to stress. We further hypothesize that such regulation has direct implications for BCa development and response to therapy. We focus on several complementary but hitherto unappreciated mechanisms that may underlie NSP surveillance under stress. The productive and long-standing collaborations between Drs. Topisirovic, Sonenberg, Mills and Ronai are now extended to include Dr. Meller, thereby enabling extensive and complementary expertise in the areas of protein synthesis and cancer biology to also include nanopore-sensing technology, enabling the resolution of ubiquitin chain topologies. Together, we will assess specific, newly identified NSP regulatory factors that function individually or in concert to regulate the cellular stress response, particularly in the context of BCa development and response to therapy. The proposed research will: (1) Establish the physiological significance of the RACK1–JNK–eEF1A2 regulatory axis to the cellular stress response, growth and therapeutic response of breast cancer. (2) Assess the role of stress-induced polysomal recruitment of Nedd8–Cullin machinery in regulating the decay of NSPs in BCa. (3) Determine the importance of UBQLN1 recruitment to polysomes in regulating newly synthesized proteins under stress conditions and in modulating the response of BCa to therapy. Our proposed studies will establish the importance and significance of select UPS components in a novel regulatory network that controls protein synthesis during cellular stress, and establish its role in BCa using a combination of BCa cultures and xenografts, RPPA technology, and TCGA dataset mining.