Abstract
RING domains act in a variety of unrelated biochemical reactions, with many of these domains forming key parts of supramolecular assemblies in cells. Here, we observe that purified RINGs from a variety of functionally unrelated proteins, including promyelocytic leukemia protein, KAP-1TIF1beta, Z, Mel18, breast cancer susceptibility gene product 1 (BRCA1), and BRCA1-associated RING domain (BARD1), self-assemble into supramolecular structures in vitro that resemble those they form in cells. RING bodies form polyvalent binding surfaces and scaffold multiple partner proteins. Separation of RING bodies from monomers reveals that self-assembly controls and amplifies their specific activities in two unrelated biochemistries: reduction of 5' mRNA cap affinity of eIF4E by promyelocytic leukemia protein and Z, and E3 ubiquitin conjugation activity of BARD1:BRCA1. Functional significance of self-assembly is underscored by partial restoration of assembly and E3 activity of cancer predisposing BRCA1 mutant by forced oligomerization. RING self-assembly creates bodies that act structurally as polyvalent scaffolds, thermodynamically by amplifying activities of partner proteins, and catalytically by spatiotemporal coupling of enzymatic reactions. These studies reveal a general paradigm of how supramolecular structures may function in cells.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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BRCA1 Protein / chemistry
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BRCA1 Protein / physiology
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Breast Neoplasms / genetics
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Carrier Proteins / chemistry
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Carrier Proteins / physiology
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Catalysis
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Cattle
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Cells / ultrastructure
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DNA-Binding Proteins / chemistry
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DNA-Binding Proteins / physiology
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Eukaryotic Initiation Factor-4E / chemistry
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Eukaryotic Initiation Factor-4E / metabolism
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Genes, BRCA1
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Humans
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Immediate-Early Proteins / chemistry
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Immediate-Early Proteins / metabolism
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Intracellular Signaling Peptides and Proteins
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Ligases / chemistry
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Ligases / metabolism
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Macromolecular Substances*
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Membrane Proteins
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Mice
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Models, Biological
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Mutation
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Neoplasm Proteins / chemistry
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Neoplasm Proteins / physiology
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Nuclear Proteins*
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Promyelocytic Leukemia Protein
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Protein Binding
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Protein Folding
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Protein Structure, Tertiary / physiology*
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RNA Caps / chemistry
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RNA Caps / metabolism
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Rabbits
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Repressor Proteins / chemistry
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Repressor Proteins / physiology
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Structure-Activity Relationship
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Thermodynamics
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Transcription Factors / chemistry
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Transcription Factors / physiology
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Tripartite Motif-Containing Protein 28
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Tumor Suppressor Proteins*
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Ubiquitin / chemistry
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Ubiquitin / metabolism
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Ubiquitin-Conjugating Enzymes*
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Ubiquitin-Protein Ligases*
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Zinc / physiology
Substances
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BRCA1 Protein
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Carrier Proteins
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DNA-Binding Proteins
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Eukaryotic Initiation Factor-4E
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Immediate-Early Proteins
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Intracellular Signaling Peptides and Proteins
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Laptm5 protein, mouse
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Macromolecular Substances
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Membrane Proteins
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Neoplasm Proteins
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Nuclear Proteins
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Pml protein, mouse
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Promyelocytic Leukemia Protein
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RNA Caps
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Repressor Proteins
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Transcription Factors
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Tumor Suppressor Proteins
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Ubiquitin
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p11 Z protein, Lymphocytic choriomeningitis virus
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PML protein, human
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UBE2D3 protein, human
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Ubiquitin-Conjugating Enzymes
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BARD1 protein, human
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Bard1 protein, mouse
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TRIM28 protein, human
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Trim28 protein, mouse
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Tripartite Motif-Containing Protein 28
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Ubiquitin-Protein Ligases
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Ligases
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Zinc