A mutation in multidrug resistance-associated protein 2 linker region prevents its internalization triggered by classic protein kinase c activation

DOMINGUEZ CJ; TOCCHETTI GN; ARIAS A; ZECCHINATI F; ARANA MR; PELLEGRINO JM; RIGALLI JP; RUIZ ML; VILLANUEVA SSM; BANCHIO C; MOTTINO AD

Congreso; Reunión Anual SAFIS 2019; 2019

INTRODUCTION: Hepatic multidrug resistance-associated protein 2 (MRP2) is a canalicular ABC Transporter contributing to bile acid-independent bile flow formation. We have previously shown that i) the activation of cPKC by thymeleatoxin (TTX) leads to internalization of MRP2 and consequently to decreased transport activity and ii) TTX induces direct phosphorylation of MRP2 in serine residues substrates of cPKC. Now we aim to identify amino acid residues (AA) targets of cPKC in MRP2 molecule and to evaluate their role in MRP2 endocytosis. EXPERIMENTAL DESIGN: After in silico prediction of cPKC target AA ranking, a plasmid encoding GFP-MRP2 fusion protein with a phosphorylation-defective mutation in the highest scoring serine (S908) was obtained by site suggesting a prominent role of this particular AA in the overall MRP2 phosphorylation. CONCLUSION: S908 appears to be decisive in the modulation of MRP2 localization and activity under TTX mediated cPKC activation. Moreover, phosphorylation of this AA likely regulates phosphorylation of other serine residues substrates of cPKC.