KCTD15 INDUCES GIANT VACUOLES IN MAMMALIAN CELLS

VALERIA ZARELLI; M MILAGROS LOPEZ DE ARMENTIA; MARÍA ISABEL COLOMBO

Villa de Merlo, San Luis.

Congreso; XXXV Reunión Científica Anual de la SBCuyo; 2017

Sociedad de Biología de Cuyo

Kctd15 belongs to the potassium channel tetramerization domain (KCTD) proteins that contain bric-a-brac, tramtrak and broad complex (BTB) domain. The BTB domain is a protein-protein interaction motif that is found throughout eukaryotes. Kctd15 homologs are found in different vertebrates, representing a well -conserved family. It has been demonstrated that Kctd15 affect Wnt signaling and AP-2 transcription factor function during embryonic development in zebrafish. The precise molecular mechanism of these processes remains unknown. To better understand the role of Kctd15 we transfected CHO, MEF and HeLa cells with Kct15-FOS plasmid and analyzed the protein localization by immunofluorescence and confocal microscopy. We observed the formation of giant vacuoles when we overexpressed Kctd15 in mammalian cells. In order to characterize these structures we used endosomal markers, such as Rab5, Rab7, CD63 and lysosomal markers (Lysotraker). Our recent results indicate that these vacuoles do not acquired Rab5, Rab7 neither CD63. In addition, Lysotraker was not observed inside the vacuoles. Taken together, these results suggest that the vacuoles induced by Kctd15 are not endosomal compartments. However, we did observe accumulation of GFP protein inside the vacuoles, indicating that the membrane of the vacuole may be permeable. We consider that the particular phenomenon induced by Kctd15 overexpression might be part of the regulation of some of the pathways it modulates.