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Identification of TMEM126A as OXA1L-interacting protein reveals cotranslational quality control in mitochondria.

Molecular cell (2024-01-11)
Sabine Poerschke, Silke Oeljeklaus, Luis Daniel Cruz-Zaragoza, Alexander Schenzielorz, Drishan Dahal, Hauke Sven Hillen, Hirak Das, Laura Sophie Kremer, Anusha Valpadashi, Mirjam Breuer, Johannes Sattmann, Ricarda Richter-Dennerlein, Bettina Warscheid, Sven Dennerlein, Peter Rehling
RÉSUMÉ

Cellular proteostasis requires transport of polypeptides across membranes. Although defective transport processes trigger cytosolic rescue and quality control mechanisms that clear translocases and membranes from unproductive cargo, proteins that are synthesized within mitochondria are not accessible to these mechanisms. Mitochondrial-encoded proteins are inserted cotranslationally into the inner membrane by the conserved insertase OXA1L. Here, we identify TMEM126A as a OXA1L-interacting protein. TMEM126A associates with mitochondrial ribosomes and translation products. Loss of TMEM126A leads to the destabilization of mitochondrial translation products, triggering an inner membrane quality control process, in which newly synthesized proteins are degraded by the mitochondrial iAAA protease. Our data reveal that TMEM126A cooperates with OXA1L in protein insertion into the membrane. Upon loss of TMEM126A, the cargo-blocked OXA1L insertase complexes undergo proteolytic clearance by the iAAA protease machinery together with its cargo.

MATÉRIAUX
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Description du produit

Millipore
Gel d'affinité ANTI-FLAG® M2, purified immunoglobulin, buffered aqueous glycerol solution
Sigma-Aldrich
Anti-PTCD3 antibody produced in rabbit, Prestige Antibodies® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution