Fibrillarin from Archaea to human

Abstract

Fibrillarin is an essential protein that is well known as a molecular marker of transcriptionally active RNA polymerase I. Fibrillarin methyltransferase activity is the primary known source of methylation for more than 100 methylated sites involved in the first steps of preribosomal processing and required for structural ribosome stability. High expression levels of fibrillarin have been observed in several types of cancer cells, particularly when p53 levels are reduced, because p53 is a direct negative regulator of fibrillarin transcription. Here, we show fibrillarin domain conservation, structure and interacting molecules in different cellular processes as well as with several viral proteins during virus infection.

Hijacking of the nucleolar protein fibrillarin by TGB1 is required for cell‐to‐cell movement of Barley stripe mosaic virus

“…Fib2 can be divided into four regions according to sequence characteristics (Rodriguez-Corona et al, 2015), with one region containing the glycine-arginine-rich (GAR) domain functioning in interactions with various viral proteins (VPs) (Kim et al, 2007b;Semashko et al, 2012). Therefore, the Fib2, GAR domain and a truncation mutant (Fib2 ᭝GAR ) were cloned into E. coli cells and purified.…”

ELF18‐INDUCED LONG NONCODING RNA 1 evicts fibrillarin from mediator subunit to enhance PATHOGENESIS‐RELATED GENE 1 (PR1) expression

“…In addition to RNA processing, fibrillarin is implicated in DNA damage, abiotic stress, apoptosis, chromatin remodeling, and transcription mechanism. Moreover, to a large extent, its functional diversity is conferred upon by its interacting partner (Rodriguez‐Corona et al ., ). Thus far, physiological functions of fibrillarin in plants are poorly understood.…”

“…It is mainly located in the fibrillar center and dense fibrillar component region of the nucleoli, where it is directly involved in several steps of ribosome biogenesis. Besides pre‐ribosomal RNA (rRNA) processing, fibrillarin is implicated in several cellular processes, including oncogenesis, viral progression, apoptosis, chromatin remodeling, basal transcription assembly, and transcription initiation, suggesting it is active in subcellular locations other than the nucleoli (Rodriguez‐Corona et al ., ; Shubina et al ., ). In plants, one of the fibrillarin proteins, FIBRILLARIN 2 (FIB2), has been found in association with the RNA Polymerase II transcription mediator complex as subunit 36a (Bäckström et al ., ).…”

A Functional Genomics Approach to Henipavirus Research: The Role of Nuclear Proteins, MicroRNAs and Immune Regulators in Infection and Disease

“…Fibrillarin has also been shown to methylate glutamine residue 104 of the human histone H2A, weakening its binding to the FACT (facilitator of chromatin transcription) complex and impacting chromatin remodelling and rDNA transcription by RNA Pol I (Tessarz et al 2013), which points at an additional role for fibrillarin in ribosome biogenesis and translation. Fibrillarin itself is methylated on several arginine residues by protein arginine N-methyltransferase 1 (PRMT1), which is thought to influence its activity (Rodriguez-Corona et al 2015). Expression levels of fibrillarin have been shown to be regulated by p53 through direct binding to fibrillarin intron 1.…”

“…X-ray data have suggested that the methylation of rRNA requires the formation of this complex with involvement of four fibrillarin molecules interacting with different regions of the target rRNAs. The yeast equivalent of fibrillarin, NOP1, has been more extensively studied than the human counterpart but fibrillarin is a well-conserved protein in most organisms, reinforcing the notion that all post-transcriptional processes involving fibrillarin such as chemical modification (methylation) of rRNA, pre-rRNA cleavage and ribosome assembly are essential for proper cellular functioning (Rodriguez-Corona et al 2015).…”