1
Linda M. Hendershot is in the Department of Tumor Cell
Biology, St Jude Children's Research Hospital,
332 North Lauderdale Street, Memphis, Tennessee 38105, USA.
Most proteins that are secreted or expressed on a cell surface are synthesized
on membrane polysomes and enter the endoplasmic reticulum (ER) as unfolded
polypeptide chains. A complex series of interactions with resident enzymes
and molecular chaperones ensure that these proteins are folded and assembled
to achieve their correct tertiary structures before being transported to the
Golgi and along the secretory pathway. However, the mechanism by which properly
folded molecules are sorted from incompletely or improperly folded proteins
and from the resident proteins that guide this process remains unclear.
