Premium
The nascent polypeptide‐associated complex (NAC) of yeast functions in the targeting process of ribosomes to the ER membrane
Author(s) -
Wiedmann Brigitte,
Prehn Siegfried
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)01118-7
Subject(s) - endoplasmic reticulum , ribosome , saccharomyces cerevisiae , signal peptide , membrane , biochemistry , translation (biology) , microbiology and biotechnology , microsome , yeast , biology , chemistry , in vitro , messenger rna , peptide sequence , rna , gene
We study here the binding of ribosomes to the endoplasmic reticulum (ER) membrane and its dependence on nascent polypeptide‐associated complex (NAC). For this, we use an in vitro translation system in combination with isolated microsomes. Importantly, all components in the system are derived from a single source, Saccharomyces cerevisiae . Ribosome nascent chains (RNCs) of the two naturally occurring invertase species (secreted or cytosolic) were prepared in wild‐type, ΔαNAC or Δαβ 1 β 3 NAC translation lysates and tested for binding to the corresponding microsomal membranes. We provide evidence that NAC prevents binding of RNCs without a signal sequence to yeast membranes. In the absence of NAC, signal‐less RNCs are able to bind to ER membranes. However, following puromycin treatment, only very few nascent chains translocate into the lumen, as detected by glycosylation.