Abstract
Nordihydroguaiaretic acid (NDGA) blocks intra-Golgi protein transport in a cell-free system and prolactin secretion from GH3 cells [Tagaya, M., Henomatsu, N., Yoshimori, T., Yamamoto, A., Tashiro, Y., and Fukui, T. (1993) FEBS Lett. 324, 201-204]. To determine which intracellular secretory pathway(s) is inhibited by NDGA, we investigated its effect on the transport of the vesicular stomatitis virus-encoded glycoprotein in BHK-21 cells. NDGA blocked protein transport from the endoplasmic reticulum to the Golgi apparatus, and from the trans-Golgi network to the plasma membrane. In addition, it retarded the brefeldin A-induced retrograde transport of mannosidase II to the endoplasmic reticulum. Although NDGA had an inhibitory effect on protein synthesis, it induced the expression of BiP, a chaperone located in the endoplasmic reticulum. The induction of BiP may be a consequence of the inhibition of protein transport by NDGA.
