Shedding light on the mitochondrial matrix through a functional membrane transporter
Researchers of IQOG-CSIC, the Institute of Oncology of Principado de Asturias (IUOPA), and the University of the Basque Country (UPV-EHU) have developed the first fluorescent small molecules that are actively channeled into the mitochondrial matrix by a mitochondrial membrane transporter (the carnitine-acylcarnitine translocase) in living cells. The new molecules have a minimalist structural design consisting of a chromophoric subunit covalently bonded to L-carnitine, a gamma-amino acid involved in metabolism of mammals, plants, and some bacteria, which acts as the biotargeting subunit that is recognized by the membrane transporter. The internalization of the fluorescent probes is both, stereospecific and independent of the mitochondrial membrane potential, in sharp contrast to known mitochondria-specific probes. The new molecules are promising research tools to investigate the role of the carnitine system in cancer metabolic rewiring and related alterations in metabolic diseases for the development of new therapies.