CISD1 gene expression mediated by CFTR activity

TAMINELLI, G.L.; VALDIVIESO, A.G.; CLAUZURE, M.; MASSIP COPIZ, M.M.; TEIBER, M.L.; SÁNCHEZ, F.; SANTA COLOMA, T.A.

Puerto Madryn, Chubut, Argentina

Congreso; XLVI Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Using Differential Display (DD), we have observed that CISD1 gene expression was decreased in a Cystic Fibrosis cell model. The first objective was to corroborate the DD results. We have studied the CISD1 expression levels by semi quantitative RT-PCR and RT followed by real-time PCR in the presence of CFTR inhibitors or activators in different cell models. The next objective was to determine the subcellular localization of CISD1. We have used the expression of a chimera bound to EGFP and confocal microscopy. It was observed that CISD1 encodes a protein with mitochondrial localization. The function of this protein is unknown but other authors reported a possible role in oxidative phosphorylation and electron transport chain. We also study whether mitochondrial complex l (mCl) activity was affected by the differential CISD1 expression. We have measured the in gel mCl activity by using Blue Native-PAGE (BN-PAGE), in mitochondria isolated from different cell models. We observed that the reduced mCl activity in CF cells can be restored by ectopic expression of CISD1, while CISD1 protein mutated in the binding site 2Fe2S interfered with normal mCl activity of non-CF cells. These results suggest that CISD1 might has a role in regulation of mCI activity and also, a role in the CF phenotype. Acknowledgments: ANPyCT (PICT 00628), CONICET (PIP 11220080102551). CONICET (AGV), UCA (GLT)