Miss Ashleigh Kropp - ACRF Chemical Biology division

Miss Ashleigh Kropp - ACRF Chemical Biology division

Seminar Room 1
Start Time: 
Fri, 16/08/2019 - 1:00pm
End Time: 
Fri, 16/08/2019 - 2:00pm

Structural and functional characterisation of two interacting pseudokinase scaffolds

M.Phil Completion seminar hosted by Associate Professor Isabelle Lucet

The human pseudokinases SgK269 and SgK223 are oncogenic interacting scaffolds that promote the assembly of specific tyrosine kinase signaling pathways. SgK223 and SgK269, as well as the recently discovered PEAK3, belong to the PEAK family of protein pseudokinases. They are large, multidomain proteins that are comprised of a N-terminal region of unknown structure and function, a large unstructured PEST region containing tyrosine phosphorylation sites and a C-terminal domain comprised of a pseudokinase domain flanked by regulatory helices. Overexpression of SgK223 and SgK269 leads to increased cell migration and changes in cell morphology, hallmarks of cancerous cells.

During her MPhil, Ashleigh investigated the assembly and function of SgK223 and SgK269. Using biochemical and biophysical techniques, Ashleigh has begun to characterise the N-terminal domain of SgK223 and SgK269 and identified the residues in their pseudokinase domain that contribute to oligomerisation of SgK223 and SgK269. Additionally, she characterised the PEAK family interactions with the critical signalling adaptor protein, CrkII, using biophysical assays and X-ray crystallography. Furthermore, these studies were complemented with microscopy techniques to investigate the localisation of these pseudokinases to focal adhesions. Insights into the scaffolding functions of SgK223 and SgK269 will inform how they contribute to the assembly of signalling pathways and hence their role in cancer.