Protein kinase C mediates juvenile hormone-dependent phosphorylation of Na+/K+-ATPase to induce ovarian follicular patency for yolk protein uptake
Protein kinase C mediates juvenile hormone-dependent phosphorylation of Na+/K+-ATPase to induce ovarian follicular patency for yolk protein uptake
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蛋白激酶 C 介导 Na( )/K( )-ATP 酶的保幼激素依赖性磷酸化，以诱导卵泡通畅以摄取卵黄蛋白。
DOI：
10.1074/jbc.ra118.005692
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发表时间：
2018-12-28
影响因子：
4.8
通讯作者：
Zhou, Shutang
中科院分区：
文献类型：
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作者：
Jing, Yu-Pu;An, Hongli;Zhou, Shutang
在卵生动物中，卵黄发生是产卵后产卵和胚胎发育的先决条件。为了成功的昆虫卵黄发生和卵子发生，在脂肪体（与脊椎动物肝脏和脂肪组织同源）中合成的卵黄原蛋白（Vg）必须通过细胞间通道（称为滤泡上皮中的开放性）到达卵母细胞表面。在许多昆虫中，这一过程受保幼激素（JH）控制，但其潜在机制仍不清楚。以前的研究表明Na+/K+-ATP酶可能参与了通畅的启动，但同样，缺乏Na+/K+-ATP酶用于通畅启动的调节级联。使用飞蝗作为一个模型系统，我们在这里报告，RNA干扰介导的敲除基因编码的Na+/K+-ATP酶，抑制其磷酸化，或抑制其活性的原因失去通畅性，导致阻碍Vg摄取，逮捕卵母细胞成熟，卵巢生长受损。JH触发G蛋白偶联受体（GPCR）、受体酪氨酸激酶（RTK）、磷脂酶C（PLC）、三磷酸肌醇受体（IP 3 R）和蛋白激酶C（PKC）使氨基酸残基Ser（8）处的Na+/K+-ATP酶亚基磷酸化，从而激活Na+/K +-ATP酶，诱导卵黄发生滤泡上皮开放。因此，我们的研究结果指出了一个以前未确定的机制，JH通过GPCR，RTK，PLC，IP 3R和PKC的信号级联诱导Na+/K+-ATP酶的磷酸化和激活。这些发现促进了我们对JH在昆虫卵黄发生和卵子发生中的调控的理解。
In oviparous animals, vitellogenesis is prerequisite to egg production and embryonic growth after oviposition. For successful insect vitellogenesis and oogenesis, vitellogenin (Vg) synthesized in the fat body (homologue to vertebrate liver and adipose tissue) must pass through the intercellular channels, a condition known as patency in the follicular epithelium, to reach the surface of oocytes. This process is controlled by juvenile hormone (JH) in many insect species, but the underlying mechanisms remain elusive. Previous work has suggested the possible involvement of Na+/K+-ATPase in patency initiation, but again, the regulatory cascade of Na+/K+-ATPase for patency initiation has been lacking. Using the migratory locust Locusta migratoria as a model system, we report here that RNAi-mediated knockdown of gene coding for Na+/K+-ATPase, inhibition of its phosphorylation, or suppression of its activity causes loss of patency, resulting in blocked Vg uptake, arrested oocyte maturation, and impaired ovarian growth. JH triggers G protein-coupled receptor (GPCR), receptor tyrosine kinase (RTK), phospholipase C (PLC), inositol trisphosphate receptor (IP3R), and protein kinase C (PKC) to phosphorylate Na+/K+-ATPase -subunit at amino acid residue Ser(8), consequently activating Na+/K+-ATPase for the induction of patency in vitellogenic follicular epithelium. Our results thus point to a previously unidentified mechanism by which JH induces the phosphorylation and activation of Na+/K+-ATPase via a signaling cascade of GPCR, RTK, PLC, IP3R, and PKC. The findings advance our understanding of JH regulation in insect vitellogenesis and oogenesis.