A SPLICS reporter reveals $${{{{{\boldsymbol{\alpha }}}}}}$$-synuclein regulation of lysosome-mitochondria contacts which affects TFEB nuclear translocation
Flavia Giamogante, Lucia Barazzuol, Francesca Maiorca, Elena Poggio, Alessandra Esposito, Anna Masato, Gennaro Napolitano, Alessio Vagnoni, Tito Calí, Marisa Brini
Abstract
Abstract Mitochondrial and lysosomal activities are crucial to maintain cellular homeostasis: optimal coordination is achieved at their membrane contact sites where distinct protein machineries regulate organelle network dynamics, ions and metabolites exchange. Here we describe a genetically encoded SPLICS reporter for short- and long- juxtapositions between mitochondria and lysosomes. We report the existence of narrow and wide lysosome-mitochondria contacts differently modulated by mitophagy, autophagy and genetic manipulation of tethering factors. The overexpression of α-synuclein (α-syn) reduces the apposition of mitochondria/lysosomes membranes and affects their privileged Ca 2+ transfer, impinging on TFEB nuclear translocation. We observe enhanced TFEB nuclear translocation in α-syn-overexpressing cells. We propose that α-syn, by interfering with mitochondria/lysosomes tethering impacts on local Ca 2+ regulated pathways, among which TFEB mediated signaling, and in turn mitochondrial and lysosomal function. Defects in mitochondria and lysosome represent a common hallmark of neurodegenerative diseases: targeting their communication could open therapeutic avenues.