Characterization of the Unfolded Protein Response by fluorescent reporters in single cells

DANIELA CHINY BARRIONUEVO; ALEJANDRO COLMAN-LERNER; MATÍAS BLAUSTEIN

Rosario

Congreso; L Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2014

SAIB

The Unfolded Protein Response (UPR) is a cellular stress signaling cascade that can be activated by different signals such as accumulation of misfolded proteins in the lumen of the Endoplasmic Reticulum (ER). This homeostatic response, which involves the activation of three parallel pathways (IRE1, PERK and ATF6), promotes cell survival in the short term but stimulates apoptosis if misfolded protein levels remain high. UPR deregulation plays an important role in malignant neoplasms as myeloma, breast and prostate cancer. In order to characterize UPR dynamics in human single cells, we created a set of fluorescent reporters to monitor the activation of each UPR pathway in real time. These constructs allowed us to measure cell-to-cell variation in the activation of UPR, an analysis that cannot be done by standard technics like western blot or PCR. Moreover, these reporters proved to be useful to analyze the dynamic movement of UPR components along different subcellular compartments. Our goal is to find well-defined patterns that provide us with information about the state of the cell and which can be associated to a specific cell fate. In the long term, we hope that these patterns can help us to understand why certain cells develop tolerance to stress conditions or escape antitumor drugs.