Issues

Lysosomal exocytosis in hypertrophic chondrocytes, mediated at least partially by VAMP8, causes release of lysosomal hydrolases that can contribute to cartilage resorption in the growth plate. This image shows double immunofluorescence labelling of lysosome-associated membrane protein 1 (LAMP1) (red) colocalised with the v-SNARE protein VAMP8 (green) at the cell surface of cultured mouse epiphyseal chondrocytes. Merged data are shown in the right-hand column. VAMP8 partially colocalises with LAMP1 in perinuclear regions of the cell under basal conditions (row 1). Ionomycin treatment induces the redistribution of VAMP8 and LAMP1 to the plasma membrane, where they are colocalised (row 2). This redistribution is blocked by the addition of EGTA (row 3), and by preincubation of the cells with the microtubule-depolymerising agent nocodazole prior to ionomycin treatment (row 4). See the article by Bastow et al. (doi: 10.1242/bio.2012547).