Altered lipid content in CHO cells overexpressing the P5-ATPase ATP13A2.

MOLINARI MARIA FLORENCIA; MAZZITELLI LUCIANA ROMINA; CORRADI GERARDO RAUL; ADAMO HUGO PEDRO; DE TEZANOS PINTO FELICITAS

Tucuman

Congreso; IIILAFeBS, IX IberoAmerican congress of Biophysics, XLV SAB Annual Meeting; 2016

Sociedad Argentina de Biofisica

Tipo: PósterTópico: Membrane Transporters and Channels Altered lipid content in CHO cells overexpressing theP5-ATPase ATP13A2Molinari, Ma. Florencia, Mazzitelli,Luciana R., Corradi, Gerardo R., Adamo, Hugo P. and de Tezanos Pinto,Felicitas. From IQUIFIB-Facultad de Farmacia y Bioquímica, Universidad de BuenosAires, Junín 956, Buenos Aires 1113, Argentina The P-type ion pumpsare membrane transporters energized by ATP-hydrolysis. They were classifiedinto five subfamilies termed P1-P5; the substrate specificity of P5 subfamilyis still unknown. Five genes named ATP13A1-ATP13A5that belong to the P5-ATPases are present in humans. Mutations in the ATP13A2 gene (also known as PARK9 or CNL12) underlay a form of Parkinson (1) and a form of NeuronalCeroid Lipofuscinosis (2). ATP13A2 is localized in lysosomes and late endosomes(LE). Dysfunction of this protein diminishes the lysosomal degradation, theautophagic flux (3) and the exosome externalization (4). We have recently shownthat ATP13A2 expression caused a reduction of the iron-induced lysosomemembrane permeabilization (5), which suggests that ATP13A2 overexpressionimproves the lysosome and LE membrane integrity. In this line, we analyzed the contentof lipids like phosphatidylethanolamine (PE) and ceramide in ATP13A2-expressingCHO cells by fluorescence microscopy. We found that the expression of ATP13A2increases the PE content, reflecting an augmented lipidosis in these cells. Besides,the ceramide level was reduced, suggesting that the degradation of membranecomponents that take place in acidic compartments is being affected. The PE contentmeasured by fluorescence quenching assay in the mitochondrial fraction containinglysosomes and LEs of ATP13A2-expressing CHO cells, was increased in thecytoplasmic leaflet of these acidic vesicles. These results suggest thatATP13A2 may be involved in the lipid homeostasis of these subcellularorganelles. [1]Ramirez A, et al. (2006) Nat. Genet.; 38(10):1184-91. [2]Bras J, et al. (2012) Hum. Mol. Genet.;21(12):2646-50. doi:10.1093/hmg/dds089. [3]Dehay B, et al. (2012) Autophagy; 8(9):1389?1391.[4]Kong, S.M., et al. (2014) Hum. Mol. Genet.; 23(11):2816-33. doi:10.1093/hmg/ddu099.[5] Rinaldi, D.E., etal. (2015)Biochim Biophys Acta;1848,1646-1655. doi:10.1016/j.bbamem.2015.04.008.