Athena's Research Interest
I am interested in understanding the effect of IBMPFD-linked mutations on the biochemical properties of p97. IBMPFD is associted with Inclusion Body Myopathy (IBM) that presents adult-onset proximal and distal weakness, early-onset Paget's disease of the Bone (PDB) and premature frontotemperol dementia.
IBMPFD is a lethal hereditary disease caused by single missense mutations in the gene encoding the p97, which is an essential component in ERAD and IBMPFD-linked mutations lead to dysfunctional ERAD in cells, however, the pathogenesis of the disease remains largely unknown.
Figure 1. A p97 protomer consists of an N-terminal (N) domain (Yellow), two AAA domains (D1 and D2, marine and slate, respectively), and a C-terminal region. Ten IBMPFD-linked mutated residues are clustered at the interface between the N and the D1 domain of p97. More importantly, they all form part of an interaction network which locks the N domain in the "co-planar" conformation, leading to our hypothesis that mutation of such residues would lead to changes in the conformation of the N domain, and hence the biochemical properties of p97.
Figure 2. Interactions formed between IBMPFD affected residues. (a) Interaction between R155 on N domain and N387 on D1 domain is one of the 'latches' that lock N domain into specific conformation relative to D1 domain; (b) R93 and R95 on N domain are surface-accessible residues and they interact with residues (E195 and E196) on D1 linker (green); (c) Interactions between R159 and A232. A232 on D1-domain is interacting with R159 on N-domain of neighbouring protomer and contribute to stabilization of hexamer formation of p97; (d) Interactions between R191 on N-D1 linker and neighbouring residues on D1 domain; (e) L198 on D1 linker.
I aim at the biochemical characterization of mutant forms of p97 implicated in IBMPFD, in order to gain better insights into the pathogenesis of the disease. My works include assessment of the stability of IBMPFD-linked mutants of p97 using Differential Scanning Fluorimetry and study of their ATPase activity using the malachite green assay.