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Published February 28, 2023 | Supplemental Material + Submitted
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MTCH2 is a mitochondrial outer membrane protein insertase


In the mitochondrial outer membrane, tail-anchored (TA) proteins play critical roles in cytoplasmic-mitochondrial communication. Using genome-wide CRISPRi screens, we identify factors involved in mitochondrial TA biogenesis in human cells. We show that MTCH2, and its paralog MTCH1, are required for insertion of biophysically diverse mitochondrial TAs, but not outer membrane β-barrel proteins. In a reconstituted system, purified MTCH2 is sufficient to mediate insertion into proteoliposomes. Functional and mutational studies reveal that MTCH2 uses membrane-embedded hydrophilic residues to function as a gatekeeper for outer membrane protein biogenesis, controlling mislocalization of TAs into the endoplasmic reticulum and the sensitivity of leukemia cells to apoptosis. Our identification of MTCH2 as an insertase provides a mechanistic explanation for the diverse phenotypes and disease states associated with MTCH2 dysfunction.One-Sentence SummaryMTCH2 is both necessary and sufficient for insertion of diverse α-helical proteins into the mitochondrial outer membrane, and is the defining member of a family of insertases that have co-opted the SLC25 transporter fold.

Additional Information

The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. We thank T. Pleiner and Z. Levine for careful reading and input on the manuscript. We thank: the Whitehead Institute Flow Cytometry Core and Kathy Daniels for access to FACS machines; the Whitehead Institute Genome Technology Core for support with sequencing of screen libraries; the Caltech Flow cytometry facility; and the Ting-Yu Wang and the Proteome Exploration Laboratory at Caltech for support for mass spectrometry. Research reported in this publication was supported by: Howard Hughes Medical Institute (JSW), Human Frontier Science Program 2019L/LT000858 (AG), the Heritage Medical Research Institute (RMV), and the Larry L. Hillblom Foundation (AJI). Competing Interest Statement. JMR consults for Maze Therapeutics and is a consultant for and equity holder in Waypoint Bio. JSW declares outside interest in 5 AM Venture, Amgen, Chroma Medicine, KSQ Therapeutics, Maze Therapeutics, Tenaya Therapeutics, Tessera Therapeutics and Third Rock Ventures. RMV is a consultant and equity holder in Gate Bioscience.

Attached Files

Submitted - 2022.09.15.508165v1.full.pdf

Supplemental Material - media-1.pdf

Supplemental Material - media-2.xlsx

Supplemental Material - media-3.xlsx

Supplemental Material - media-4.xlsx


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August 20, 2023
December 22, 2023