Two novel proteins in the mitochondrial outer membrane mediate beta-barrel protein assembly.
Mitochondrial outer and inner membranes contain translocators that achieve protein translocation across and/or insertion into the membranes. Recent evidence has shown that mitochondrial beta-barrel protein assembly in the outer membrane requires specific translocator proteins in addition to the components of the general translocator complex in the outer membrane, the TOM40 complex. Here we report two novel mitochondrial outer membrane proteins in yeast, Tom13 and Tom38/Sam35, that mediate assembly of mitochondrial beta-barrel proteins, Tom40, and/or porin in the outer membrane. Depletion of Tom13 or Tom38/Sam35 affects assembly pathways of the beta-barrel proteins differently, suggesting that they mediate different steps of the complex assembly processes of beta-barrel proteins in the outer membrane.
Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
Daigo
D
Ishikawa
Hayashi
H
Yamamoto
Yasushi
Y
Tamura
Kaori
K
Moritoh
Toshiya
T
Endo
D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D002478:Cells, Cultured; D005690:Galactose / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000096:biosynthesis; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D033681:Mitochondrial Membrane Transport Proteins; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D018272:Porins / Q000096:biosynthesis; D011401:Promoter Regions, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
C492709:MIM1 protein, S cerevisiae; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D024101:Mitochondrial Proteins; D018272:Porins; C092812:SAM37 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C487333:Sam50 protein, S cerevisiae; C492710:TOM38 protein, S cerevisiae; C066555:Tom40 protein, S cerevisiae; D005690:Galactose