Post-translational transfer into ER?

[Ian A. York]

Is there a way to reliably load peptides into the lumen of the ER, 
post-translationally?  What we'd like to do is load cells (by osmotic 
loading) with a peptide, and compare effects when it's in the cytosol and 
when it's in the ER.  I have a vague memory of some bacterial toxin that 
targets ER, but it is, alas, too vague to actually be useful.

Ian 

-- 
    Ian York   (iayork at panix.com)  <http://www.panix.com/~iayork/>
    "-but as he was a York, I am rather inclined to suppose him a
     very respectable Man." -Jane Austen, The History of England