The lipid transport protein StarD7 level modifies mitochondrial dynamics

MARÍA LAURA ROJAS; MARIANO, CRUZ DEL PUERTO; JÉSICA FLORES-MARTIN; ANDREA MIRANDA; LUCILE KOURDOVA; GRACIELA PANZETTA DE DUTARI; SUSANA GENTI-RAIMONDI

Mar del Plata

Congreso; Reunión Conjunta SAIC SAI SAFIS 2018; 2018

Sociedad Argentina de Investigación Clínica

Mitochondria are dynamics organelles crucial for cell function andsurvival implicated in oxidative energy production. Mitochondriallipids affect several important functions such as respiratory metabolism,membrane architecture, protein import, mitophagy and mitochondrialdynamics. StarD7 is a lipid transport protein that carriesphosphatidylcholine (PC) to the mitochondria. Previous studieshave shown that StarD7 knockdown induces alterations in mitochondriaand endoplasmic reticulum morphology with a reduction inmitochondrial PC content, however how different StarD7 levels affectsthe mitochondrial dynamics was unexplored. Here, we generateda HTR-8/SVneo stable cell line expressing the StarD7-I isoform(StarD7-I) that has a mitochondrial targeting signal. We demonstratedthat StarD7 overexpression promotes altered mitochondrial morphologywith greater mitochondria motility. Mitochondrial targetingphotoactivable (PA-GFP) protein assays indicated that mitochondriafrom StarD7-I-overexpressing cells were able to produce transientfusions. StarD7-I cells maintain the mitochondrial membrane potentialand generate lower ROS levels than control cells. Additionally,an increase in the expression of Drp-1 fission protein was detectedin StarD7-I cells. Based on these data, we concluded that StarD7-Ioverexpression leads to transient mitochondria fusion events withoutaffecting the mitochondrial membrane potential