Abstract
A yeast two-hybrid screen was employed to identify human proteins that specifically bind the amino-terminal 400 amino acids of the retinoblastoma (Rb) protein. Two independent cDNAs resulting from this screen were found to encode the carboxy-terminal 137 amino acids of MCM7, a member of a family of proteins that comprise replication licensing factor. Full-length Rb and MCM7 form protein complexes in vitro, and the amino termini of two Rb-related proteins, p107 and p130, also bind MCM7. Protein complexes between Rb and MCM7 were also detected in anti-Rb immunoprecipitates prepared from human cells. The amino-termini of Rb and p130 strongly inhibited DNA replication in an MCM7-dependent fashion in a Xenopus in vitro DNA replication assay system. These data provide the first evidence that Rb and Rb-related proteins can directly regulate DNA replication and that components of licensing factor are targets of the products of tumor suppressor genes.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Cell Cycle Proteins*
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DNA Replication*
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DNA, Complementary / genetics
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism*
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Humans
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Male
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Minichromosome Maintenance Complex Component 7
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Molecular Sequence Data
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Ovum
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Peptide Fragments / genetics
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Peptide Fragments / metabolism
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Phosphoproteins / metabolism
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Protein Binding
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Proteins*
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Recombinant Proteins / metabolism
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Retinoblastoma Protein / genetics
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Retinoblastoma Protein / metabolism*
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Retinoblastoma-Like Protein p107
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Retinoblastoma-Like Protein p130
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Spermatozoa
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Xenopus
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Xenopus Proteins*
Substances
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Cell Cycle Proteins
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DNA, Complementary
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DNA-Binding Proteins
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Nuclear Proteins
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Peptide Fragments
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Phosphoproteins
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Proteins
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RBL1 protein, human
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RBL2 protein, human
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Recombinant Proteins
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Retinoblastoma Protein
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Retinoblastoma-Like Protein p107
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Retinoblastoma-Like Protein p130
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Xenopus Proteins
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MCM7 protein, human
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Mcm7 protein, Xenopus
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Minichromosome Maintenance Complex Component 7