Characterization of clofibrate-induced retrograde Golgi membrane movement to the endoplasmic reticulum: Clofibrate distinguishes the Golgi from the trans Golgi network

Clofibrate-induced retrograde Golgi membrane movement was blocked or retard ed when NRK cells were treated with sodium azide/2-deoxyglucose, nocodazole , taxol, and destruxin B, indicating that it depends on energy, and the dyn amic state of microtubules, and being acidic or vacuolar-type ATPase functi on. PDMP and phospholipase A(2) inhibitors also blocked it. These character istics are similar to those of brefeldin A (BFA) and nordihydroguaiaretic a cid (NDGA), inducers of retrograde Golgi membrane movement. However, clofib rate was distinguished from BFA in that BFA action was insensitive to phosp holipase A2 inhibitors and from NDGA in that NDGA stabilized microtubules a gainst nocodazole and its action was almost insensitive to taxol. The trams Golgi network (TGN) was resistant to clofibrate, while BFA and NDGA disper sed it. To our knowledge, clofibrate is the first drug to show such differe nt effects on the Golgi and TGN and, therefore, is expected to be a useful tool to distinguish their architecture and/or membrane dynamics.