核仁是主要致力于核糖体生物发生的多功能核域。某些病毒开发了通过调节核糖体RNA(rRNA)加工来操纵宿主核仁蛋白以促进其复制的策略。这种关联干扰核仁功能,导致核糖体生物发生过度激活或停滞。诱导或抑制细胞凋亡,影响应激反应。核仁原纤蛋白(FBL)是一些动植物病毒的重要靶标。FBL是一种重要且高度保守的S-腺苷甲硫氨酸(SAM)依赖性甲基转移酶,能够通过其固有无序区域(IDR)降解rRNA,富含甘氨酸/精氨酸(GAR)结构域。它形成核糖核蛋白复合物,指导前rRNA的100多个位点的2'-O-甲基化。它参与多个细胞过程,包括转录的启动,肿瘤发生,和细胞凋亡,在其他人中。与动物病毒的相互作用,包括人类病毒,触发了它重新分布到核质和细胞质,干扰其在前rRNA加工中的作用。具有IDR作为核衣壳的病毒编码蛋白质,矩阵,Tat蛋白,甚至是病毒snoRNA,可以与FBL关联,迫使核仁蛋白经历非典型功能。在这里,我们回顾了动物和人类病毒用来篡夺FBL功能的分子机制以及对细胞过程的影响。特别是在核糖体生物发生中。
The nucleolus is a multifunctional nuclear domain primarily dedicated to ribosome biogenesis. Certain viruses developed strategies to manipulate host nucleolar proteins to facilitate their replication by modulating ribosomal RNA (rRNA) processing. This association interferes with nucleolar functions resulting in overactivation or arrest of ribosome biogenesis, induction or inhibition of apoptosis, and affecting stress response. The nucleolar protein fibrillarin (FBL) is an important target of some plant and animal viruses. FBL is an essential and highly conserved S-adenosyl methionine (SAM) dependent methyltransferase, capable of rRNA degradation by its intrinsically disordered region (IDR), the glycine/arginine-rich (GAR) domain. It forms a ribonucleoprotein complex that directs 2\'-O-methylations in more than 100 sites of pre-rRNAs. It is involved in multiple cellular processes, including initiation of transcription, oncogenesis, and apoptosis, among others. The interaction with animal viruses, including human viruses, triggered its redistribution to the nucleoplasm and cytoplasm, interfering with its role in pre-rRNA processing. Viral-encoded proteins with IDRs as nucleocapsids, matrix, Tat protein, and even a viral snoRNA, can associate with FBL, forcing the nucleolar protein to undergo atypical functions. Here we review the molecular mechanisms employed by animal and human viruses to usurp FBL functions and the effect on cellular processes, particularly in ribosome biogenesis.