Prazosin induced lysosomal tubulation interferes with cytokinesis and the endocytic sorting of the tumour antigen CD98hc

Publication date: September 2018Source: Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Volume 1865, Issue 9Author(s): Robert Fuchs, Anika Stracke, Viktoria Holzmann, Gerfried Luschin-Ebengreuth, Nathalie Meier-Allard, Nadine Ebner, Teresa Maria Lassacher, Markus Absenger-Novak, Eleonore Fröhlich, Matthias Schittmayer, Sara Cano Crespo, Manuel Palacin, Beate Rinner, Ruth Birner-GruenbergerAbstractThe quinazoline based drug prazosin (PRZ) is a potent inducer of apoptosis in human cancer cells. We recently reported that PRZ enters cells via endocytosis and induces tubulation of the endolysosomal system. In a proteomics approach aimed at identifying potential membrane proteins with binding affinity to quinazolines, we detected the oncoprotein CD98hc. We confirmed shuttling of CD98hc towards lysosomes and upregulation of CD98hc expression in PRZ treated cells. Gene knockout (KO) experiments revealed that endocytosis of PRZ still occurs in the absence of CD98hc - suggesting that PRZ does not enter the cell via CD98hc but misroutes the protein towards tubular lysosomes. Lysosomal tubulation interfered with completion of cytokinesis and provoked endoreplication. CD98hc KO cells showed reduced endoreplication capacity and lower sensitivity towards PRZ induced apoptosis than wild type cells. Thus, loss of CD98hc does not affect endocytosis of PRZ and lysosomal tubulation, but the ability for endoreplication and survival of cells. Furthermore, we found that glutamine, l...
Source: Biochimica et Biophysica Acta (BBA) Molecular Cell Research - Category: Molecular Biology Source Type: research