种系为研究RNP颗粒的调节和功能提供了极好的体内系统。胚芽颗粒是保守的种系特异性RNP颗粒,位于秀丽隐杆线虫成年性腺中,在RNA维持中起作用。regulation,和监视。在秀丽隐杆线虫中,当卵子发生经历延长的减数分裂停滞时,胚芽颗粒蛋白和其他RNA结合蛋白组装成更大的RNP颗粒,其假设功能是调节RNA代谢和维持卵母细胞质量。为了深入了解卵母细胞RNP颗粒的功能,在这份报告中,我们表征了停滞卵母细胞中RNP颗粒的四种蛋白质成分的不同阶段。我们发现RNA结合蛋白PGL-1是动态的,并且具有类似液体的特性,虽然本质上无序的蛋白质MEG-3具有凝胶样特性,与胚胎小胚芽颗粒中两种蛋白质的性质相似。我们发现MEX-3表现出几种凝胶状特性,但比MEG-3更具动态性,而CGH-1是动态的,但不能始终表现出类似液体的特性,并且可能是RNP颗粒中的中间相。RNA结合蛋白的这些不同阶段对应于,并可能成为其基础,对压力的不同反应。有趣的是,在卵母细胞RNP颗粒中,MEG-3不是PGL-1或其他RNA结合蛋白的缩合所必需的,这不同于MEG-3在小型,胚芽颗粒。最后,我们显示PUF-5翻译阻遏物似乎促进MEX-3和MEG-3凝聚成较大的RNP颗粒;然而,这种作用可能与卵子发生的调节有关。
The germ line provides an excellent in vivo system to study the regulation and function of RNP granules. Germ granules are conserved germ line-specific RNP granules that are positioned in the Caenorhabditis elegans adult gonad to function in RNA maintenance, regulation, and surveillance. In Caenorhabditis elegans, when oogenesis undergoes extended meiotic arrest, germ granule proteins and other RNA-binding proteins assemble into much larger RNP granules whose hypothesized function is to regulate RNA metabolism and maintain oocyte quality. To gain insight into the function of oocyte RNP granules, in this report, we characterize distinct phases for four protein components of RNP granules in arrested oocytes. We find that the RNA-binding protein PGL-1 is dynamic and has liquid-like properties, while the intrinsically disordered protein MEG-3 has gel-like properties, similar to the properties of the two proteins in small germ granules of embryos. We find that MEX-3 exhibits several gel-like properties but is more dynamic than MEG-3, while CGH-1 is dynamic but does not consistently exhibit liquid-like characteristics and may be an intermediate phase within RNP granules. These distinct phases of RNA-binding proteins correspond to, and may underlie, differential responses to stress. Interestingly, in oocyte RNP granules, MEG-3 is not required for the condensation of PGL-1 or other RNA-binding proteins, which differs from the role of MEG-3 in small, embryonic germ granules. Lastly, we show that the PUF-5 translational repressor appears to promote MEX-3 and MEG-3 condensation into large RNP granules; however, this role may be associated with regulation of oogenesis.