Of coiled bodies,gems, and salmon

Coiled bodies (CBs) are nuclear organelles whose morphology and composition have been conserved from plants to animals. They are highly enriched in components of three different RNA processing pathways. Small nuclear RNAs (snRNAs) involved in pre-mRNA splicing, rRNA processing, and histone mRNA 3′ end maturation all take up residence in CBs. However, CB function(s) remain obscure. This review will focus on recent developments in several aspects of CB structure and function, including exciting new results on their twin organelles, called gems. In particular, the reader will be introduced to a novel hypothesis called the “salmon theory of snRNP biogenesis.” Questions arising from and experiments necessary to test this hypothesis will be discussed. J. Cell. Biochem. 70:181–192, 1998. © 1998 Wiley-Liss, Inc.     

snoRNP的生物发生

核仁小核糖核蛋白体颗粒(small nucleolar ribonucleoproteins partical,snoRNP)是一种定位于核仁的复合物,它由一系列核仁小RNA(small nucleolar RNA,snoRNA)和核心蛋白质结合而成。这些snoRNP指导核糖体RNA(rRNA)前体的加工修饰,在核糖体的生物发生中起着重要的作用。研究显示大多数snoRNP加工和组装的早期阶段发生在核浆,在Cajal小体(Cajal body,CB)中组装成熟之后,在PHAX、p50、p55、SMN和Nopp140等蛋白质的帮助下穿越各种不同的核间隔转运至核仁,并在核仁中发挥功能。本文对snoRNP的生物发生过程作一综述。