Dynamic virus-driven remodeling of ER-mitochondria contacts

病毒已经进化出优雅的策略来操纵宿主细胞机制并重新连接核心细胞途径，以 促进生产性感染，包括提高代谢产出和维持细胞活力。要完成 这就是说，病毒与细胞器之间有着广泛的动态分子相互作用网络。作为 细胞器的功能与它们的组成、形状和定位的调节密切相关， 细胞器结构-功能关系的控制是阐明感染后果的核心。 虽然已经描述了许多病毒诱导的细胞器重塑的例子，但对此了解甚少。 细胞器结构如何产生特定的功能。我们的实验室已经确定了一种以前未被识别的 病毒感染的一个方面，即人类病毒通过戏剧性地控制细胞器重构 重新布线细胞器间和细胞器内的膜接触部位(MCS)。使用混合定量蛋白质组学和 超分辨率显微镜方法，我们展示了在MCS网络中的精巧重组 广泛的人类病毒，包括古老的(疱疹病毒)和快速适应(流感和贝塔病毒- 冠状病毒)病毒。我们进一步发现，感染无处不在的人类疱疹病毒 巨细胞病毒(HCMV)触发一种新的特化MCS结构，线粒体-内质网包膜，我们 被称为MenC。我们确定，人巨细胞病毒感染主要驱动线粒体外围的分裂， 碎裂的线粒体进入MENC并保持其生物能量活动。感染是如何 诱导MenC的形成，这种新报道的结构的功能尚不清楚。我们建议 MENC提供了一个统一的解释，解释了长期存在的悖论，即某些病毒，如HCMV 增加线粒体的生物能量输出，尽管会导致线粒体碎裂。我们的中心假设 HCMV重塑细胞器间和细胞器内连接，产生MENC，从而保护和 稳定碎裂线粒体的生物能力。使用多学科方法，将 分子病毒学，在定量蛋白质组学，活超分辨率显微镜， 超微结构电子显微镜、代谢组学和脂类组学，在目标1中，我们将定义其机制 人巨细胞病毒感染过程中巨噬细胞的形成和功能。在目标2中，我们将确定 人巨细胞病毒诱导内质网、线粒体和溶酶体间三向接触的信号传导 外周线粒体分裂，提高生物能量呼吸。在目标3中，我们将描述病毒的特征 协调内质网-线粒体MCS重连的因素。总而言之，我们的研究将把新发现的方面联系起来 从病毒编排的MCS网络到新的双向和三向细胞器结构-功能关系 这是基本的细胞机制的基础，包括线粒体生物能量学和自噬周转。 通过这样做，我们的研究将打开病毒如何利用重塑的功能能力的研究领域 感染的细胞器，这对病毒的发病机制和代谢紊乱具有广泛的意义。

Viruses have evolved elegant strategies to manipulate host cell machinery and rewire core cellular pathways to facilitate productive infection, including enhancing metabolic output and maintaining cell viability. To accomplish this, viruses exert an extensive network of dynamic molecular interactions with cellular organelles. As the functions of organelles are intimately associated with the regulation of their composition, shape, and localization, the control of organelle structure-function relationships is at the core of clarifying the outcome of an infection. While many examples of virus-induced organelle remodeling have been described, very little is understood about how organelle structures engender specific functions. Our lab has characterized a previously unrecognized aspect of viral infection, which is that human viruses globally control organelle remodeling by dramatically rewiring inter- and intra-organelle membrane contact sites (MCS). Using a hybrid quantitative proteomics and super resolution microscopy approach, we demonstrated exquisite reorganization in MCS networks engaged by a broad range of human viruses, including both ancient (herpesviruses) and rapidly adapting (influenza and beta- coronavirus) viruses. We further discovered that infection with the ubiquitous herpesvirus human cytomegalovirus (HCMV) triggers a new specialized MCS structure, mitochondria-ER encapsulations that we termed MENC. We determined that HCMV infection drives predominantly fission at the mitochondrial periphery, and that the fragmented mitochondria enter MENCs and retain their bioenergetic activity. How the infection induces MENC formation and the function of this newly reported structure remain unknown. We propose that MENCs provide a unifying explanation for the longstanding paradox of how certain viruses such as HCMV increase mitochondrial bioenergetic output, despite inducing mitochondrial fragmentation. Our central hypothesis is that HCMV remodels inter- and intra-organelle connections, generating MENCs, which act to protect and stabilize the bioenergetic capacity of fragmented mitochondria. Using a multidisciplinary approach that combines molecular virology with cutting-edge approaches in quantitative proteomics, live super resolution microscopy, ultrastructural electron microscopy, metabolomics, and lipidomics, in Aim 1, we will define the mechanisms underlying the formation and function of MENCs during HCMV infection. In Aim 2, we will establish what signaling cues from HCMV-induced three-way contacts among the ER, mitochondria, and lysosome stimulate peripheral mitochondria fission and elevate bioenergetic respiration. In Aim 3, we will characterize the viral factors that coordinate ER-mitochondria MCS rewiring. Collectively, our study will link newly discovered aspects of virus-orchestrated MCS networking to new two-way and three-way organelle structure-function relationships that underlie fundamental cellular mechanisms, including mitochondrial bioenergetics and autophagic turnover. In doing so, our study will open research areas in how viruses exploit the functional capacities of remodeled organelles for infection, which have broad implications for viral pathogenesis and metabolic disorders.