New mitochondrial carriers: an overview

Abstract

The transport of metabolites, nucleotides and cofactors across the mitochondrial inner membrane is performed by members of mitochondrial carrier family (MCF). These proteins share marked structural features that have made feasible the functional characterization of numerous MCs in the last years. The MCs responsible for transport activities in mitochondria known for decades such as glutamate uptake or ATP-Mg/Pi exchange have recently been identified as well as novel carriers such as those involved in S-adenosylmethionine or thiamine pyrophosphate uptake. Here, after a brief review of the novel data on structural characteristics and import mechanisms of MCF members, we present an exhaustive compilation of human MC sequences, including previously characterized carriers, together with their respective Saccharomyces cerevisiae orthologues, ordered according to the phylogenetic analysis of el Moualij and co-workers [Yeast (1997) 13: 573-581]. We have detected the existence of at least 49 human MC sequences, including those of yet unknown function. An overview of novel MCF members functionally characterized in recent years in mammals and in yeast genomes is presented.

Role of mitochondria in spontaneous rhythmic activity and intracellular calcium waves in the guinea pig gallbladder smooth muscle

“…However, emerging evidence suggests that under normal physiological conditions, PTPs release reactive oxygen species (ROS). The ROS have been shown to regulate Ca 2ϩ sparks and Ca 2ϩ waves in vascular smooth muscle (1,4,5). We evaluated the involvement of PTPs in Ca 2ϩ flash and Ca 2ϩ wave activities in intact GBSM preparations by using cyclosporin A (5 and 10 M), which inhibits PTPs by binding cyclophilin (12).…”

The Pancreatic β-Cell: A Bioenergetic Perspective

“…This last performs multiple functions, firstly, as in the primary ␤-cell, it ensures the absence of a Pasteur effect, whereby accelerated glycolysis can compensate for decreased oxidative phosphorylation when the latter is compromised. The lack of lactate dehydrogenase could actually increase the bioenergetic "efficiency" of a cell in which glucose delivery may be limiting, by preventing anaerobic glycolysis (2 ATP per glucose) and ensuring stoichiometric oxidative phosphorylation (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) ATP per glucose, depending on proton leaks). The second, related, consequence is that the Warburg effect (transition to a glycolytic phenotype) is prevented in cell lines that display low expression of lactate dehydrogenase, with the result that they retain a strong oxidative metabolism, despite being proliferating cells.…”

“…The mammalian genome encodes at least 50 inner mitochondrial membrane transporters sharing a common 6-transmembrane structure (20). The catalytic functions of many of these have been elucidated, shuttling substrates and metabolites between the matrix and cytosolic compartments.…”

Mitochondrial carriers and pores: Key regulators of the mitochondrial apoptotic program?

“…The mitochondrial carrier (MC) protein family comprises of membrane embedded proteins that catalyze the exchange of solutes across the IMM (reviewed in [40,41]). These carriers provide a link between mitochondria and cytosol, which is indispensable for the metabolic activities performed by mitochondria.…”