Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 21, 2022 | Accepted Version + Supplemental Material
Journal Article Open

MTCH2 is a mitochondrial outer membrane protein insertase


In the mitochondrial outer membrane, α-helical transmembrane proteins play critical roles in cytoplasmic-mitochondrial communication. Using genome-wide CRISPR screens, we identified mitochondrial carrier homolog 2 (MTCH2), and its paralog MTCH1, and showed that it is required for insertion of biophysically diverse tail-anchored (TA), signal-anchored, and multipass proteins, but not outer membrane β-barrel proteins. Purified MTCH2 was sufficient to mediate insertion into reconstituted proteoliposomes. Functional and mutational studies suggested that MTCH2 has evolved from a solute carrier transporter. MTCH2 uses membrane-embedded hydrophilic residues to function as a gatekeeper for the outer membrane, controlling mislocalization of TAs into the endoplasmic reticulum and modulating 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.

Additional Information

© 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. We thank J. Nunnari and M. Le Vasseur for sharing the mitochondrial split GFP system. We thank T. Pleiner for technical assistance and Z. Levine for careful reading and input on the manuscript. We thank the Whitehead Institute Flow Cytometry Core and K. 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 T. Y. Wang and for support for mass spectrometry. Research reported in this publication was supported by Howard Hughes Medical Institute (J.S.W.), Human Frontier Science Program 2019L/LT000858 (A.G.), the Heritage Medical Research Institute (R.M.V.), the Larry L. Hillblom Foundation (A.J.I.), and NIH F31-NS115380 (J.M.R.). Author contributions: A.G., J.S.W., and R.M.V. conceived the study. A.G., T.A.S., A.J.I., J.M.R., J.S.W., and R.M.V. were responsible for the design, analysis, and interpretation of experiments. A.G., T.A.S., and A.J.I. performed most of the experiments in the study with help from J.M.R., T.K.E., G.M., B.L., K.C.S., M.L.W., and A.N.P. T.C., B.L., and J.J.J. advised the design, sample processing, and analysis for all mass spectrometry experiments. A.G. and R.M.V. drafted the manuscript with input from all authors. Competing interests: J.M.R. consults for Maze Therapeutics and is a consultant for and equity holder in Waypoint Bio. J.S.W. declares outside interest in 5 AM Venture, Amgen, Chroma Medicine, KSQ Therapeutics, Maze Therapeutics, Tenaya Therapeutics, Tessera Therapeutics, and Third Rock Ventures. R.M.V. is a consultant and equity holder in Gate Bioscience.

Attached Files

Accepted Version - nihms-1847457.pdf

Supplemental Material - science.add1856_mdar_reproducibility_checklist.pdf

Supplemental Material - science.add1856_sm.pdf

Supplemental Material - science.add1856_tables_s1_to_s4.zip


Files (21.0 MB)
Name Size Download all
9.3 MB Preview Download
471.6 kB Preview Download
1.9 MB Preview Download
9.3 MB Preview Download

Additional details

August 22, 2023
December 22, 2023