Insulin-like growth factor II overexpression does not affect sorting of lysosomal enzymes in NIH-3T3 cells.
The sorting of newly synthesized mannose 6-phosphate (M6P)-containing proteins and of the major excreted protein (MEP), a lysosomal thiol proteinase, was studied in NIH-3T3 cells transfected with the cDNA of human insulin-like growth factor II (IGF II) or with the vector alone. Extracts from media and cells labelled with [35S] methionine were used for chromatography on a M6P/IGF II receptor affinity matrix or for immunoprecipitation to assess the distribution of newly synthesized M6P-containing proteins and MEP, respectively. The results indicate that the overexpression of IGF II did not affect the synthesis and the sorting of M6P-containing proteins and of MEP. The binding and uptake of the lysosomal enzyme arylsulfatase A were not affected in IGF II overexpressing cells.
Georg-August-Universität, Biochemie II, Göttingen, Germany.
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Braulke
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Bresciani
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Buergisser
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von Figura
D000818:Animals; D002460:Cell Line; D002553:Cerebroside-Sulfatase / Q000378:metabolism; D002846:Chromatography, Affinity; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004705:Endocytosis; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000502:physiology*; D007700:Kinetics; D008247:Lysosomes / Q000201:enzymology*; D008360:Mannosephosphates / Q000378:metabolism; D051379:Mice; D017527:Receptor, IGF Type 2; D011956:Receptors, Cell Surface / Q000378:metabolism; D017451:Receptors, Somatomedin; D014162:Transfection
D008360:Mannosephosphates; D017527:Receptor, IGF Type 2; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D007335:Insulin-Like Growth Factor II; D002553:Cerebroside-Sulfatase; D003546:Cysteine Endopeptidases