Intracellular transport and processing of lysosomal cathepsin B.
Intracellular transport and processing of lysosomal cathepsin B was investigated in the subcellular fractions of rat liver by pulse-labeling experiments with [35S]methionine in vivo. A newly synthesized procathepsin B with a molecular weight of 39 kDa firstly appeared in the rough microsomal fraction at 10 min postinjection of label. This procathepsin B moved from the microsomal fractions to the Golgi subfractions at 30 min postinjection, and then a processed mature enzyme appeared in the lysosomal fraction at 60 min. These results suggest that the propeptide-processing of procathepsin B takes place in lysosomes in the course of intracellular transport from endoplasmic reticulum through Golgi complex to lysosomes.
Nishimura
Y
Y
Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
Kato
K
K
D000818:Animals; D001692:Biological Transport; D002401:Cathepsin B / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D006056:Golgi Apparatus / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008247:Lysosomes / Q000201:enzymology*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D011499:Protein Processing, Post-Translational; D051381:Rats
D002401:Cathepsin B