An interaction between the SRP receptor and the translocon is critical during cotranslational protein translocation
UMass Chan Affiliations
Department of Biochemistry and Molecular PharmacologyDocument Type
Journal ArticlePublication Date
2008-03-19Keywords
Gene Expression Regulation, FungalMembrane Proteins
Mutation
Protein Biosynthesis
Protein Sorting Signals
Protein Subunits
Protein Transport
Receptors, Cytoplasmic and Nuclear
Receptors, Peptide
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins
Signal Recognition Particle
Time Factors
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
The signal recognition particle (SRP)-dependent targeting pathway facilitates rapid, efficient delivery of the ribosome-nascent chain complex (RNC) to the protein translocation channel. We test whether the SRP receptor (SR) locates a vacant protein translocation channel by interacting with the yeast Sec61 and Ssh1 translocons. Surprisingly, the slow growth and cotranslational translocation defects caused by deletion of the transmembrane (TM) span of yeast SRbeta (SRbeta-DeltaTM) are exaggerated when the SSH1 gene is disrupted. Disruption of the SBH2 gene, which encodes the beta subunit of the Ssh1p complex, likewise causes a growth defect when combined with SRbeta-DeltaTM. Cotranslational translocation defects in the ssh1DeltaSRbeta-DeltaTM mutant are explained by slow and inefficient in vivo gating of translocons by RNCs. A critical function for translocation channel beta subunits in the SR-channel interaction is supported by the observation that simultaneous deletion of Sbh1p and Sbh2p causes a defect in the cotranslational targeting pathway that is similar to the translocation defect caused by deletion of either subunit of the SR.Source
J Cell Biol. 2008 Mar 24;180(6):1149-61. Epub 2008 Mar 17. Link to article on publisher's siteDOI
10.1083/jcb.200707196Permanent Link to this Item
http://hdl.handle.net/20.500.14038/39142PubMed ID
18347066Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1083/jcb.200707196
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