In:
The Journal of Cell Biology, Rockefeller University Press, Vol. 179, No. 7 ( 2007-12-31), p. 1355-1363
Abstract:
The central channel Tom40 of the preprotein translocase of outer membrane (TOM) complex is thought to be responsible for the import of virtually all preproteins synthesized outside the mitochondria. In this study, we analyze the topogenesis of the peripheral benzodiazepine receptor (PBR), which integrates into the mitochondrial outer membrane (MOM) through five hydrophobic transmembrane segments (TMSs) and functions in cholesterol import into the inner membrane. Analyses of in vitro and in vivo import into TOM component–depleted mitochondria reveal that PBR import (1) depends on the import receptor Tom70 but requires neither the Tom20 and Tom22 import receptors nor the import channel Tom40, (2) shares the post-Tom70 pathway with the C-tail–anchored proteins, and (3) requires factors of the mitochondrial intermembrane space. Furthermore, membrane integration of mitofusins and mitochondrial ubiquitin ligase, the MOM proteins with two and four TMSs, respectively, proceeds through the same initial pathway. These findings reveal a previously unidentified pathway of the membrane integration of MOM proteins with multiple TMSs.
Type of Medium:
Online Resource
ISSN:
1540-8140
,
0021-9525
DOI:
10.1083/jcb.200702143
Language:
English
Publisher:
Rockefeller University Press
Publication Date:
2007
detail.hit.zdb_id:
1421310-2
SSG:
12
