Abstract
PML nuclear bodies (NBs) are involved in the regulation of key nuclear pathways but their biochemical function in nuclear metabolism is unknown. In this study PML NB assembly dynamics were assessed by live cell imaging and mathematic modeling of its major component parts. We show that all six nuclear PML isoforms exhibit individual exchange rates at NBs and identify PML V as a scaffold subunit. SP100 exchanges at least five times faster at NBs than PML proteins. Turnover dynamics of PML and SP100 at NBs is modulated by SUMOylation. Exchange is not temperature-dependent but depletion of cellular ATP levels induces protein immobilization at NBs. The PML-RARalpha oncogene exhibits a strong NB retention effect on wild-type PML proteins. HIPK2 requires an active kinase for PML NB targeting and elevated levels of PML IV increase its residence time. DAXX and BLM turn over rapidly and completely at PML NBs within seconds. These findings provide a kinetics model for factor exchange at PML NBs and highlight potential mechanisms to regulate intranuclear trafficking of specific factors at these domains.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Antigens, Nuclear / metabolism
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Autoantigens / metabolism
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Cell Nucleus / metabolism
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Cells, Cultured
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Diffusion
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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HeLa Cells
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Humans
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Intranuclear Inclusion Bodies / metabolism*
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Kinetics
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Models, Biological
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Nuclear Proteins / chemistry
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Oncogene Proteins, Fusion / metabolism
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Promyelocytic Leukemia Protein
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Protein Binding
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Protein Isoforms / metabolism
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Protein Processing, Post-Translational / physiology
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Protein Structure, Tertiary / physiology
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Protein Transport / physiology
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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SUMO-1 Protein / metabolism
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Substrate Specificity
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Transcription Factors / chemistry
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Transcription Factors / genetics
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Transcription Factors / metabolism*
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Tumor Suppressor Proteins / chemistry
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Tumor Suppressor Proteins / genetics
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Tumor Suppressor Proteins / metabolism*
Substances
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Antigens, Nuclear
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Autoantigens
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Nuclear Proteins
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Oncogene Proteins, Fusion
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Promyelocytic Leukemia Protein
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Protein Isoforms
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Recombinant Fusion Proteins
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SUMO-1 Protein
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Transcription Factors
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Tumor Suppressor Proteins
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promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein
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SP100 protein, human
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PML protein, human
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Green Fluorescent Proteins