A chaperone cascade sorts proteins for posttranslational membrane insertion into the endoplasmic reticulum.

ABSTRACT: Tail-anchored (TA) proteins are posttranslationally inserted into either the endoplasmic reticulum (ER) or the mitochondrial outer membrane. The C-terminal transmembrane domains (TMDs) of TA proteins enable their many essential cellular functions by specifying the membrane target, but how cells process these targeting signals is poorly understood. Here, we reveal the composition of a conserved multiprotein TMD recognition complex (TRC) and show that distinct TRC subunits recognize the two types of TMD signals. By engineering mutations in a mitochondrial TMD, we switch over its TRC subunit recognition, thus leading to its misinsertion into the ER. Biochemical reconstitution with purified components demonstrates that TRC tethers and enzymatically activates Get3 to selectively hand off ER-bou

SUBMITTER: Wang F 

PROVIDER: S-EPMC3652556 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature