Rossi M, Maiuri L, Salvati V M, Russomanno C, Auricchio S
Department of Pediatrics, University Federico II of Naples, Italy.
FEBS Lett. 1993 Dec 27;336(2):299-303. doi: 10.1016/0014-5793(93)80824-e.
The proteolytic processing of rabbit intestinal lactase-phlorizin-hydrolase (LPH) was studied by pulse-chase and continuous labeling experiments in organ culture from 15-day-old rabbits in the presence of glycosylation and processing inhibitors. Monensin and brefeldin A inhibited the two proteolytic cleavages of the precursor indicating that they are post-Golgi events as previously reported for the unique cleavage of LPH in man. The inhibition was not related to a concomitant alteration glycosylation; in fact, if trimming was blocked by MDNM the abnormal glycosylated precursor was proteolytically processed normally. Finally the use of the anti-microtubular drug colchicine strongly inhibited both cleavages and caused accumulation of the complex-glycosylated precursor form the brush border fraction indicating that proteolytic events depend on intact microtubule (transport).
