Skeletal Biology & Disease
Project 1: The contribution of protein misfolding (“unfolded protein response”) to inherited cartilage and bone disease
Inherited musculoskeletal disorders are a significant disease burden and although many mutations have been defined, our knowledge on the molecular mechanisms that cause them, and ultimately how these mechanisms could be manipulated, is only just beginning to be explored. Many of the gene mutations result in the production of mutant protein that is compromised in its ability to form the correct 3-D folded functional structures. Recent research has shown that these unfolded proteins can cause cellular stress and activate intracellular signalling pathways that have profound effects on cell gene expression that may contribute to cellular pathology (see Bateman et al.,Nature Reviews Genetics 2009 Mar;10(3):173-83). The proposed studies will explore the molecular signalling pathways using in vitro or transgenic mouse models and a range of immunohistochemical, biochemical, molecular biology, cell biology and proteomic approaches.
Project 2: The molecular signalling pathways that cause osteoarthritis
Degeneration of articular cartilage is the central pathological feature of osteoarthritis (OA) and it is this progressive erosion of cartilage that leads to joint failure and necessitates joint replacement surgery. We have a major research program determining the molecular events in the initiation and progression of cartilage breakdown. Using microarray analysis to look at gene expression changes and proteomic approaches we have determined new osteoarthritis candidate genes. Several research projects are available in this program exploring the detailed biology of these genes and the signalling pathways that result in the onset and progression of OA. These studies will involve the study of the biological function of these genes in cultured cartilage and bone cells, and how both over-expression and expression knockdown by RNAi affects cellular signalling and cell phenotype in vitro. This will compared with the changes found in osteoarthritic tissues. The projects will use of a wide range of molecular biology, biochemical, cell biology and proteomic techniques.
Project 3: mRNA surveillance in human disease: How cells detect and degrade deleterious mutant mRNA (nonsense-mediated mRNA decay)
Cells have several critical quality control processes to reduce the impact of mutations on cell function. We are studying nonsense-mediated decay (NMD), a mRNA quality mechanism that degrades mRNA containing premature stop codons. Since mutations that introduce premature stop codons account for one-third of inherited disorders, NMD is of immense importance in many diseases as well as normal development [see Hum Mol Genet. 8:1893 (1999); Am J Hum Genet 82:786 (2008)]. Our studies will explore the molecular basis of NMD by the production of mutations in reporter gene constructs we have developed to measure NMD in vitro by transfection of cells and determination of mRNA levels by PCR and primer extension assays. The project will characterise the mRNA sequences that specify NMD in different cell types and determine role of known and novel RNA binding proteins using electromobility shift assays. These trans-acting proteins will be identified by proteomics and their role in NMD tested by suppression of expression using RNA interference.
For further information on these BSc(Hons) and PhD projects, please contact
Professor John Bateman
T +61 3 8341 6422
E john.bateman@mcri.edu.au