New proteins responsible for the interaction between phagosomes and F-Actin and their role in macrophage function

吞噬体与细胞骨架的相互作用在吞噬体成熟过程中起着关键作用，从而导致病原体的杀伤。我们开发了一种体外结合实验来分析模型系统中负载胶乳头的吞噬体如何与f -肌动蛋白结合。三种细胞质因子参与了f -肌动蛋白与吞噬体的相互作用。一个负责atp依赖性结合的因子被确定为肌球蛋白Va。这种与吞噬体结合的肌球蛋白被证明可以延迟微管依赖性的逆行吞噬体向细胞中心的运动。本研究的目标是确定其他两个因素：一个高分子量（约600 kDa）的肌动蛋白结合蛋白（HMWABP）负责lbp与f -肌动蛋白的atp非依赖性结合，另一个小分子量（约15-25 kDa）的胞质蛋白抑制肌球蛋白Va和HMWABP与吞噬体的结合。肌球蛋白V和新发现的因子在调节吞噬体与f -肌动蛋白相互作用和吞噬体生物发生中的作用将在体内进行分析。

Phagosome interaction with the cytoskeleton plays a key role in phagosome maturation which leads to pathogen killing. We developed an in vitro binding assay to analyze how in model system latex bead loaded phagosomes bind to F-actin. Three cytoplasmic factors were found to be involved in the interactions between F-actin and phagosomes. One factor responsible for the ATP-dependent binding was identified as myosin Va. This myosin bound to phagosomes was shown to delay microtubule-dependent retrograde phagosome movement toward the cell center. The goal of this proposal is to identify the other two factors: a high molecular weight (> 600 kDa) actin-binding protein (HMWABP) responsible for the ATP-independent binding of LBPs to F-actin, and a small (s 15-25 kDa) cytosolic protein that inhibits association of both myosin Va and HMWABP with phagosomes. The role of myosin V and the newly identified factors in the regulation of phagosome interaction with F-actin and in phagosome biogenesis will then be analyzed in vivo.