Abstract
We have previously found that a ras switch 1 domain peptide (PNC-7, residues 35-47) selectively blocks oocyte maturation induced by oncogenic (Val 12-containing) ras-p21 protein and also blocks c-raf-induced oocyte maturation. We now find that oncogenic ras-p21 does not inhibit oocyte maturation of a constitutively activated raf protein (raf BXB) that is lacking most of the first 301 amino terminal amino acids, including the major ras binding domain and accessory ras-binding regions. We also find that a dominant negative raf that completely blocks c-raf-induced maturation likewise does not block raf-BXB-induced maturation. We conclude that PNC-7 blocks ras by binding to the amino-terminal domain of raf and that raf BXB must initiate signal transduction in the cytosol.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Binding Sites
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Enzyme Inhibitors / chemistry
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Enzyme Inhibitors / metabolism
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Enzyme Inhibitors / pharmacology
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Mitogens / chemistry
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Mitogens / metabolism
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Mitogens / pharmacology*
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Oncogene Protein p21(ras) / antagonists & inhibitors*
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Oncogene Protein p21(ras) / chemistry
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Oncogene Protein p21(ras) / metabolism
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Oncogene Protein p21(ras) / pharmacology*
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Oocytes / drug effects
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Oocytes / growth & development
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Peptide Fragments / chemistry
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Peptide Fragments / metabolism
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Peptide Fragments / pharmacology*
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Protein Binding
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Protein Structure, Tertiary
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Proto-Oncogene Proteins c-raf / antagonists & inhibitors
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Proto-Oncogene Proteins c-raf / chemistry*
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Proto-Oncogene Proteins c-raf / genetics
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Proto-Oncogene Proteins c-raf / metabolism*
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Signal Transduction / drug effects*
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Xenopus laevis
Substances
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Enzyme Inhibitors
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Mitogens
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Peptide Fragments
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Proto-Oncogene Proteins c-raf
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Oncogene Protein p21(ras)