Format

Send to

Choose Destination
Nature. 1994 Aug 11;370(6489):434-40.

A protein complex required for signal-sequence-specific sorting and translocation.

Author information

1
Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021.

Abstract

We have purified a nascent-polypeptide-associated complex (NAC) which prevents short ribosome-associated nascent polypeptides from inappropriate interactions with proteins in the cytosol. NAC binds nascent-polypeptide domains emerging from ribosomes unless a signal peptide is fully exposed. Depletion of cytosolic proteins (including NAC) from ribosomes carrying nascent polypeptides allows the signal recognition particle (SRP) to crosslink to polypeptides irrespective of whether or not they contain signal peptides. In the absence of cytosol, proteins lacking signal peptides can be mistranslocated into the endoplasmic reticulum in vitro, albeit with low efficiency. Readdition of NAC restores the specificity of SRP and fidelity of translocation.

PMID:
8047162
DOI:
10.1038/370434a0
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center