Abstract
We have previously reported that cathepsin L mRNA is present in unfertilized eggs of Sarcophaga peregrina (flesh fly) as a maternal mRNA, which suggests that cathepsin L is required for embryogenesis. Now we have identified an egg protein, with a molecular mass of 100 kDa, that is extremely susceptible to cathepsin L digestion and which disappears rapidly as the embryos develop. We purified this protein to homogeneity, cloned its cDNA, and found that it contained a consensus sequence for the active site of tyrosine phosphatase. In fact this protein showed tyrosine phosphatase activity, indicating that it is a novel tyrosine phosphatase. The expression and subsequent disappearance of this protein, which we have named egg-derived tyrosine phosphatase (EDTP), may be indispensable for embryogenesis of Sarcophaga.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Animals
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Base Sequence
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Binding Sites / genetics
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Cathepsin L
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Cathepsins / metabolism
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Cloning, Molecular
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Consensus Sequence / genetics
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Cysteine Endopeptidases
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Cysteine Proteinase Inhibitors / pharmacology
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Diptera / embryology*
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Diptera / enzymology
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Egg Proteins / genetics*
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Egg Proteins / metabolism
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Embryo, Nonmammalian / cytology
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Embryonic Development
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Endopeptidases*
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Fluorescent Antibody Technique
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Gene Expression Regulation, Developmental / genetics
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Insect Proteins / genetics
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Insect Proteins / metabolism
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Leucine / analogs & derivatives
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Leucine / pharmacology
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Molecular Sequence Data
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Oocytes / enzymology*
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Protein Tyrosine Phosphatases / metabolism*
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RNA, Messenger / metabolism
Substances
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Cysteine Proteinase Inhibitors
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Egg Proteins
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Insect Proteins
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RNA, Messenger
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Protein Tyrosine Phosphatases
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Cathepsins
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Endopeptidases
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Cysteine Endopeptidases
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Cathepsin L
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Leucine
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E 64