Changes in proteinase activities during the differentiation of murine erythroleukemia cells.
Changes in intracellular proteinase activities were examined during DMSO-induced differentiation of murine erythroleukemia cells. Suc-APA-MCA hydrolytic activity was significantly decreased, and apparent ATP-dependent multicatalytic proteinase activity was also decreased with MEL cell differentiation. Cathepsin B and L activity was mainly present in the microsomal fraction of control cells, but a part of this activity had shifted to the lysosomal fraction of differentiated cells. With the translocation of cathepsin B from the microsomal to the lysosomal fraction, the pro-enzyme form of cathepsin B was converted into the mature enzyme. These results suggest that the lysosomal pathway contributes to the degradation of specific proteins with cell differentiation.
Tsukahara
T
T
National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan.
Ishiura
S
S
Kominami
E
E
Sugita
H
H
D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D004915:Leukemia, Erythroblastic, Acute / Q000201:enzymology* / Q000473:pathology; D008247:Lysosomes / Q000502:physiology; D051379:Mice; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
D010450:Endopeptidases; D004121:Dimethyl Sulfoxide