Accurate gene expression and regulation in mammalian cells is a hugely complex process, essential for cellular and organismal homeostasis. The physical organisation of gene expression within the cell, in turn, requires precise and complex compartmentalization within the nucleus and cytoplasm of the cell. This compartmentalization occurs using numerous sub-cellular structures that are not formed using membranes, but by processes of phase separation driven by the interactions between RNA and protein molecules.
In several progressive human diseases associated with ageing, faulty messenger RNA molecules containing expanded repeat sequences (for example >100 copies of the triplet CUG in Myotonic Dystrophy Type 1 and expansion within the C9orf72 locus associated with Amyotrophic Lateral Sclerosis) form foci in the nucleus of the cell. These foci interfere with gene expression and regulation, although the details of how this happens are not understood. Pre-mRNA splicing is widely reported to be affected, but other essential processes such as polyadenylation; 5’ capping; intra-cellular transport and mRNA degradation have not been widely studied in this context. We have recently discovered that the presence of these expanded RNA foci also alters the physical structure, dynamics and molecular composition of a number of phase separated cellular structures required for correct gene regulation. We have generated novel cell lines in which we can induce these foci to use as a model to investigate cellular structures and molecular pathways required for accurate gene expression and regulation.
This project will use these novel cell lines, and generate related cell lines, to address a number of linked questions.
1) What is the biophysical nature of the disease-associated RNA foci?
2) Which aspects of gene expression and regulation are affected by the presence of the foci?
3) In what way are the morphology and dynamic behaviour of phase-separated cellular structures affected by the foci?
Taken together, the answers to these questions will provide valuable insights into the fundamental cellular organisation of gene expression and regulation.
The training provided by the project will include molecular biology; cell culture; quantitative proteomics; microscopy including 3 dimensional time-lapse, superresolution (Airyscan and SIM) and photokinetic analyses; data analysis and electron microscopy.
This project is also advertised within the BBSRC EASTBIO Doctoral Training Partnership. Informal enquiries about the project and funding arrangements are strongly encouraged and should be made by email to Dr Judith Sleeman ([Email Address Removed]).
How To Apply
Please make a formal application to the School of Biology through our Online Application Portal.
We require the following documents; CV, personal statement, 2 references, academic qualifications, English language qualification (if applicable).
References:
The Cajal body and the nucleolus: "In a relationship" or "It's complicated"?
Trinkle-Mulcahy L, Sleeman JE.
RNA Biol. 2017 Jun 3;14(6):739-751. doi: 10.1080/15476286.2016.1236169.
Liquid phase condensation in cell physiology and disease.
Shin Y, Brangwynne CP.
Science. 2017 Sep 22;357(6357). pii: eaaf4382. doi: 10.1126/science.aaf4382
Continue with Facebook
