U. Tatu et al., MEMBRANE GLYCOPROTEIN FOLDING, OLIGOMERIZATION AND INTRACELLULAR-TRANSPORT - EFFECTS OF DITHIOTHREITOL IN LIVING CELLS, EMBO journal, 12(5), 1993, pp. 2151-2157
Using influenza hemagglutinin (HA0) and vesicular stomatitis virus G p
rotein as model proteins, we have analyzed the effects of dithiothreit
ol (DTT) on conformational maturation and transport of glycoproteins i
n the secretory pathway of living cells. While DTT caused reduction of
folding intermediates and misfolded proteins in the endoplasmic retic
ulum (ER), it did not affect molecules that had already acquired a mat
ure trimeric conformation, whether present in the ER or elsewhere. The
conversion to DTT resistance was therefore a pre-Golgi event. Reducti
on of folding intermediates was dependent on the intactness of the ER
and on metabolic energy, suggesting cooperativity between DTT and ER f
olding factors. DTT did not inhibit most cellular functions, including
ATP synthesis and protein transport within the secretory pathway. The
results established DTT as an effective tool for analyzing the foldin
g and compartmental distribution of proteins with disulfide bonds.