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

ABSTRACT: 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.

SUBMITTER: Poerschke S 

PROVIDER: S-EPMC10805001 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature