Renal Fanconi Syndrome Is Caused by a Mistargeting-Based Mitochondriopathy

Autor: Nadine Assmann, Katja Dettmer, Johann M.B. Simbuerger, Carsten Broeker, Nadine Nuernberger, Kathrin Renner, Holly Courtneidge, Enriko D. Klootwijk, Axel Duerkop, Andrew Hall, Robert Kleta, Peter J. Oefner, Markus Reichold, Joerg Reinders
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Cell Reports, Vol 15, Iss 7, Pp 1423-1429 (2016)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2016.04.037
Popis: Summary: We recently reported an autosomal dominant form of renal Fanconi syndrome caused by a missense mutation in the third codon of the peroxisomal protein EHHADH. The mutation mistargets EHHADH to mitochondria, thereby impairing mitochondrial energy production and, consequently, reabsorption of electrolytes and low-molecular-weight nutrients in the proximal tubule. Here, we further elucidate the molecular mechanism underlying this pathology. We find that mutated EHHADH is incorporated into mitochondrial trifunctional protein (MTP), thereby disturbing β-oxidation of long-chain fatty acids. The resulting MTP deficiency leads to a characteristic accumulation of hydroxyacyl- and acylcarnitines. Mutated EHHADH also limits respiratory complex I and corresponding supercomplex formation, leading to decreases in oxidative phosphorylation capacity, mitochondrial membrane potential maintenance, and ATP generation. Activity of the Na+/K+-ATPase is thereby diminished, ultimately decreasing the transport activity of the proximal tubule cells. : Assmann et al. examine the molecular mechanism underlying a recently described Fanconi syndrome. Mistargeting of the peroxisomal protein EHHADH to mitochondria leads to impaired mitochondrial fatty acid β-oxidation and respiration, resulting in decreased ATP production. Diminished transport activity leads to the observed Fanconi syndrome. Keywords: Fanconi syndrome, mitochondriopathy, fatty acid oxidation, supercomplexes
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