Translocation of proteins across the endoplasmic reticulum. II. Signal recognition protein (SRP) mediates the selective binding to microsomal membranes of in-vitro-assembled polysomes synthesizing secretory protein

Translocation of proteins across the endoplasmic reticulum. II. Signal recognition protein (SRP) mediates the selective binding to microsomal membranes of in-vitro-assembled polysomes synthesizing secretory protein

Translocation of proteins across the endoplasmic reticulum.

Translocation-competent microsomal membrane vesicles of dog pancreas were shown to selectively bind nascent, in vitro assembled polysomes synthesizing secretory protein (bovine prolactin) but not those synthesizing cytoplasmic protein (alpha and beta chain of rabbit globin) . This selective polysome binding capacity was abolished when the microsomal vesicles were salt-extracted but was restored...

Translocation of Proteins Across the Endoplasmic Reticulum

Translocation-competent microsomal membrane vesicles of dog pancreas were shown to selectively bind nascent, in vitro assembled polysomes synthesizing secretory protein (bovine prolactin) but not those synthesizing cytoplasmic protein (alpha and beta chain of rabbit globin) . This selective polysome binding capacity was abolished when the microsomal vesicles were salt-extracted but was restored...

Translocation of proteins across the endoplasmic reticulum. I. Signal recognition protein (SRP) binds to in-vitro-assembled polysomes synthesizing secretory protein

An 11S protein composed of six polypeptide chains was previously purified from a salt extract of dog pancreas microsomal membranes and shown to be required for translocation of nascent secretory protein across the microsomal membrane (Wistar and Blobel 1980 Proc. Natl. Acad. Sci. U. S. A. 77:7112-7116). This 11S protein, termed signal recognition protein (SRP), has been shown here (a) to inhibi...

Signal Recognition Protein ( SRP ) Causes Signal Sequence - dependent and Site - specific Arrest of Chain Elongation that is Released by Microsomal Membranes

The previously observed (Walter, et al. 1981 1. Cell Biol. 91 :545-550) inhibitory effect of SRP selectively on the cell-free translation of mRNA for secretory protein (preprolactin) was shown here to be caused by a signal sequence-induced and site-specific arrest in polypeptide chain elongation. The M r of the SRP-arrested nascent preprolactin chain was estimated to be 8,000 corresponding to-7...