Determining the interaction of Pex5 with kinases and the phosphorylation status of peroxisome proteins.
Disciplines
Life Sciences
Abstract (300 words maximum)
Peroxisomes are cellular organelles critical in the metabolism of lipids and reactive oxygen species. Peroxisomes are highly dynamic rapidly changing size, abundance and protein content in response to environmental conditions. These changes, collectively referred to as peroxisome biogenesis, rely on peroxisome biogenesis factors, Pex proteins that together regulate peroxisome function. Current research, has put the spotlight on reversible protein phosphorylation to regulate peroxisome dynamics, with Pex proteins in yeast, like pex11p and pex14p requiring phosphorylation for their function. This project focusses on a critical peroxisome biogenesis protein Pex5 – a peroxisome translocation signal-1 (PTS1) receptor, that binds to peroxisome proteins in the cytoplasm and transports them to the peroxisome. Preliminary studies in our lab using yeast two hybrid assay have shown that full length Pex5 interacts weakly with a stress activated kinase- MK2, indicating the potential of phosphorylation of Pex5 and/or Pex5 associated proteins. This study seeks to confirm the interaction of Pex5 with MK2 using a GST-pulldown assay as well determine the phosphorylation status of proteins associating with GST-Pex5 fusion proteins using phosphor-serine and phosphor-tyrosine antibodies. Results from this study will provide valuable information on this crucial oxidative stress combatting organelle, specifically on mechanisms of protein import into the peroxisome and provide insight into how phosphorylation regulates peroxisome function.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Rajnish Singh
Additional Faculty
Carol Chrestensen, Chemistry and Biochemistry, chresten@kennesaw.edu
Determining the interaction of Pex5 with kinases and the phosphorylation status of peroxisome proteins.
Peroxisomes are cellular organelles critical in the metabolism of lipids and reactive oxygen species. Peroxisomes are highly dynamic rapidly changing size, abundance and protein content in response to environmental conditions. These changes, collectively referred to as peroxisome biogenesis, rely on peroxisome biogenesis factors, Pex proteins that together regulate peroxisome function. Current research, has put the spotlight on reversible protein phosphorylation to regulate peroxisome dynamics, with Pex proteins in yeast, like pex11p and pex14p requiring phosphorylation for their function. This project focusses on a critical peroxisome biogenesis protein Pex5 – a peroxisome translocation signal-1 (PTS1) receptor, that binds to peroxisome proteins in the cytoplasm and transports them to the peroxisome. Preliminary studies in our lab using yeast two hybrid assay have shown that full length Pex5 interacts weakly with a stress activated kinase- MK2, indicating the potential of phosphorylation of Pex5 and/or Pex5 associated proteins. This study seeks to confirm the interaction of Pex5 with MK2 using a GST-pulldown assay as well determine the phosphorylation status of proteins associating with GST-Pex5 fusion proteins using phosphor-serine and phosphor-tyrosine antibodies. Results from this study will provide valuable information on this crucial oxidative stress combatting organelle, specifically on mechanisms of protein import into the peroxisome and provide insight into how phosphorylation regulates peroxisome function.