Pre-mRNA splicing is highly complex. Over a hundred proteins and several RNA species assemble into dynamic complexes, in a pathway defined by several stable partial complexes. However, the relevance of these has been challenged and very little is known about transient or unstable components. Even less is known about the mechanisms by which many proteins affect the selection of splice sites. Splicing reactions in vitro cannot be reconstituted from pure components but require nuclear extracts. We will use single molecule fluorescence to follow the order, stoichiometry and rates of assembly and disassembly of components during splicing reactions. In effect, we will watch individual protein molecules as they join the splicing complex. This methodology may have widespread uses for other complex processes, such as transcription. We have recently made a breakthrough in studies on the mechanisms by which splicing is regulated. PTB is a major splicing regulatory protein, implicated in the control of tissue-specific splicing. In collaboration with Prof. C.W.J. Smith and co-workers in Cambridge, we have used single molecule methods to determine the number of molecules of PTB bound to a regulated exon in complexes assembled in nuclear extracts. This has allowed us to identify where PTB molecules are bound on the pre-mRNA and to formulate models for their mode of action. The project offered is to use the same methods to study the processes during which splice sites are selected in pre-mRNA. A strong background in mathematics or physics is not essential but would be helpful.
We are an equal opportunities employer and particularly welcome applications for Ph.D. places from women, minority ethnic and other under-represented groups.