STARD7 DEPLETIONINDUCES ENDOPLASMIC RETICULUM STRESS (ER) AND GOLGI APPARATUS FRAGMENTATION

FLORES-MARTÍN JÉSICA; CRUZ DEL PUERTO, MARIANO; REYNA LUCIANA; ALVAREZ CECILIA INÉS; PANZETTA DE DUTARI GRACIELA; GENTI DE RAIMONDI SUSANA

Mar del Plata

Congreso; SAIB; 2015

Lipid and protein transport between organelles is an essential process in the organization of the different cellcompartments. StarD7 is an intracellular lipid transport protein, member of the START domain superfamily, which isinvolved in many physiological processes such as lipid transfer, metabolism, and modulation of signaling pathways.StarD7facilitates the delivery of phosphatidylcholine to the mitochondria and previous results indicated that StarD7silencing decreased ABCG2 multidrug transporter level, cell migration, proliferation, and phospholipid synthesis.Also, StarD7 silencing produced an increase in basal ROS as well as in H2O2-induced ROS levels.Here, we report that HepG2 cells transfected with StarD7 siRNA during 72 h and analyzed by transmission electronmicroscopy showed altered mitochondria and ER morphology. These changes were accompanied with an ER stressresponse measured by augmented expression levels of inositol-requiring enzyme 1 (IRE1α), calnexin, glucoseregulated protein 78/immunoglobulin heavy chain-binding protein (Grp78/BiP), and protein kinase-like ER kinase(PERK). In addition, immunofluorescence assay revealed that StarD7 knockdown induced Golgi apparatusfragmentation, labeled by anti-Giantin. In summary, our results provide novel evidence for an important role ofStarD7 in maintaining cell homeostasis. Supported by FONCyT, CONICET, SECyT-UNC.LI-P20CADMIUN ALTERS THE LIPID METABOLISM IN RAT MAMMARY