Our lab is studying the mechanisms regulating secretory protein homeostasis under both normal and pathological conditions. We focus on understanding how the quality control machinery of the endoplasmic reticulum (ER) promotes efficient protein folding under various conditions. Proper folding and quality control of secretory proteins are crucial to cell viability. Accumulation of misfolded proteins can lead to loss of protein function and cell death. Cells activate the unfolded protein response (UPR) to cope with misfolded protein accumulation in the ER, but excessive UPR can trigger apoptosis. UPR activation has been associated with various diseases such as diabetes, Huntington’s disease and cardiac dysfunction. We employ mammalian tissue culture models, yeast genetics, molecular biology, quantitative live cell imaging techniques and high-throughput RNA-SEQ to understand how cells detect, respond and cope with misfolded proteins.
Jiang Y., Di Gregorio SE, Duennwald ML. and Lajoie P. 2017. Polyglutamine toxicity in yeast uncovers phenotypic variations between different fluorescent protein fusions. Traffic. 18(1):58-70.
Chadwick SR., Pananos AD, Di Gregorio SE, Park AE, Etedali-Zadeh P, Duennwald ML. and Lajoie P. 2016. A toolbox for rapid assessment of chronological lifespan and survival in Saccharomyces cerevisiae. Traffic. (6): 689-703. including journal cover
Jiang Y, Chadwick SR. and Lajoie P. 2016. Endoplasmic reticulum stress: the cause and answer to Huntington’s disease. Brain Research. 1648(Pt B):650-657.
Lajoie P.*,Fazio EN. and Snapp EL.* 2014. Approaches to imaging unfolded secretory protein stress in living cell. Endoplasmic Reticulum Stress in Diseases. 1, 27– 39 *co-corresponding authors
Berger AC., Kelly JJ., Lajoie P., Shao Q. and Laird DW. 2014. Skin disease and non-syndromic hearing loss-linked Cx30 mutations exhibit several distinct cellular pathologies. J Cell Sci. Apr 15;127 (Pt 8):1751
Lajoie P., Moir RD., Willis IM., Snapp EL. 2012. Kar2p availability defines various forms of endoplasmic reticulum stress in living cells. Mol. Biol. Cell. 23(5): 955-64