A molecular scaffold that mediates box C/D snoRNP biogenesis
Lead Research Organisation:
Newcastle University
Department Name: Inst for Cell and Molecular Biosciences
Abstract
Individual functions in the cell are harnessed and controlled, often within large molecular machines. Examples include the activities that replicate DNA, synthesise proteins and generate RNA. Correct assembly of these machines is performed in a controlled way, far from their site of function. This is important as partially or incorrectly assembled complexes are likely to interfere with the normal processes in the cell. We wish to study the assembly of one family of such cellular machines, the box C/D snoRNPs, complexes that are important for the production of the machinery that produces proteins in the cell. Our aim is to study the role of assembly factors in the formation of the box C/D snoRNPs.
Technical Summary
Structural, non-coding RNAs (ncRNAs) perform essential roles in almost all aspects of gene expression. They function as stable RNA-protein complexes, known as ribonucleoproteins (ncRNPs) that are often assembled in the cell at locations separate from their site of function. The biogenesis of ncRNPs has several common underlying themes which include: 1) assembly of the ncRNA into a precursor complex (pre-ncRNP) which aids or directs the binding of the ncRNP proteins. 2) processing the ncRNA. This includes either the removal of extra sequences at the 3' and/or 5' ends or modification of the nucleotides. 3) association of transport/localisation factors with the pre-ncRNP. Recent work indicates that all of these activities are co-ordinated and in several cases form part of a multifunctional and dynamic pre-ncRNP complex. However, the underlying principles of this process are poorly understood. Using the box C/D small nucleolar RNPs (snoRNPs / essential for ribosome biogenesis) as an example, we propose to study the co-ordination of distinct activities integral to ncRNP biogenesis. Our previous data has shown that activities responsible for assembly, localisation and RNA processing are present in a large, dynamic pre-snoRNP complex. Furthermore, the recruitment and function of these activities is highly regulated. In this current work we propose to investigate the formation of the pre-snoRNP complex and to analyse how this co-ordinates the assembly of the snoRNP and the recruitment of the RNA processing machinery.
Organisations
People |
ORCID iD |
Nicholas Watkins (Principal Investigator) |
Publications
Wells G
(2017)
The ribosome biogenesis factor yUtp23/hUTP23 coordinates key interactions in the yeast and human pre-40S particle and hUTP23 contains an essential PIN domain
in Nucleic Acids Research
Wells GR
(2016)
The PIN domain endonuclease Utp24 cleaves pre-ribosomal RNA at two coupled sites in yeast and humans.
in Nucleic acids research
McKeegan KS
(2009)
Evidence that the AAA+ proteins TIP48 and TIP49 bridge interactions between 15.5K and the related NOP56 and NOP58 proteins during box C/D snoRNP biogenesis.
in Molecular and cellular biology
Van Nues RW
(2011)
Box C/D snoRNP catalysed methylation is aided by additional pre-rRNA base-pairing.
in The EMBO journal
Knox AA
(2011)
A weak C' box renders U3 snoRNA levels dependent on hU3-55K binding.
in Molecular and cellular biology
Ghalei H
(2010)
A novel Nop5-sRNA interaction that is required for efficient archaeal box C/D sRNP formation.
in RNA (New York, N.Y.)
Description | 1) We have characterised a scaffold of assembly/biogenesis factors that is essential for snoRNP assembly. We have identified NUFIP as a protein that regulates this process and shown that the scaffold also recruits factors necessary for snoRNA processing. 2) We have provided strong evidence that phosphorylation of snoRNP proteins specifically regulates snoRNP formation, localisation and function. 3) We have investigated snoRNP structure and found novel snoRNA-rRNA base-pairing interactions |
Exploitation Route | Defects in the formation and function of RNA-protein complexes in the cell result in a number of genetic diseases and are also linked to cancer. This information therefore provides key insights and novel targets for novel chemotheraputics to combat these conditions. This research has opened up new avenues of research for the lab and resulted in preliminary data for a Wellcome-funded grant. This research has also provided important information about the assembly and localisation of RNP complexes |
Sectors | Pharmaceuticals and Medical Biotechnology,Other |