Send to

Choose Destination
Cell. 1995 Jul 28;82(2):261-70.

A posttargeting signal sequence recognition event in the endoplasmic reticulum membrane.

Author information

Max Delbrück Center for Molecular Medicine, Berlin-Buch, Federal Republic of Germany.


We have analyzed early phases of the cotranslational transport of the secretory protein preprolactin through the mammalian endoplasmic reticulum (ER) membrane. Following recognition of the signal sequence of the nascent polypeptide chain in the cytosol by the SRP, the chain is transferred into the membrane, where a second signal sequence recognition step takes place for which the presence in the lipid bilayer of the Sec61p complex is essential and sufficient. This step leads to a tight junction between the ribosomenascent chain complex and the Sec61p complex, and to the productive insertion of the nascent chain into the translocation site. These results show that a translocation substrate is subjected to two recognition events before being allowed to cross the ER membrane.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center