Supervisor's Name: Andrey V. Cybulsky
Supervisor's Email: andrey.cybulsky [at] mcgill.ca
Supervisor's Phone: 514-398-8148
Supervisor's department: Physiology
Course number: PHGY 396 (Physiology)
Term: Fall 2014-2015
Project start date: September 1, 2014
Project end date: December 4, 2014
Project title: Effect of complement C5b-9 membrane attack complex on nephrin maturation and expression
Project description (50-100 words suggested): Normal structure and localization of proteins in or near the filtration slit-diaphragm is critical to the maintenance of glomerular permselectivity. Nephrin, the key component of the slit-diaphragm, undergoes important post-translational modification in the endoplasmic reticulum (ER) prior to export to the plasma membrane. Nephrin expression in slit-diaphragms is reduced in proteinuric diseases (including membranous nephropathy), but understanding of the mechanism is limited. We will test the hypothesis that C5b-9 signaling induces nephrin misfolding, which reduces cell surface nephrin expression, and thereby impairs permselectivity. We will determine if complement alters nephrin expression in the plasma membrane and the perinuclear region of cells by immunofluorescence (IF) microscopy. A shift from the membrane to the perinuclear region would suggest misfolding and retention in the ER. We will use IF microscopy to verify nephrin in the ER by assessing colocalization with calnexin, an ER marker. Calnexin is also an ER chaperone, and its association with immature glycoproteins or misfolded proteins facilitates their folding. A misfolded protein shows increased association with calnexin. To verify that C5b-9 triggers nephrin misfolding, we will assess nephrin association with calnexin and its glycosylation status by co-immunoprecipitation. In complement-treated cells, we expect to see both enhanced association of nephrin with calnexin and impaired maturation.
Prerequisite: 1 term completed at McGill + CGPA of 3.0 or higher; or permission of instructor.
Grading scheme (The final report must be worth at least 50% of final grade): Laboratory performance and final written report
Project status: This project is taken. The professor has no more '396' projects this term.
How students can apply / Next steps: Bring a printed copy of this application form and your advising transcript to me during office hours.
Ethics, safety, and training: Supervisors are responsible for the ethics and safety compliance of undergraduate students. This project involves NEITHER animal subjects, nor human subjects, nor biohazardous substances, nor radioactive materials, nor handling chemicals, nor using lasers.