Abstract
2',3'-Cyclic nucleotide-3'-phosphodiesterase (CNP) is firmly associated with tubulin from brain tissue and FRTL-5 thyroid cells as demonstrated by copolymerization with microtubules through several warm/cold cycles, the presence of CNP activity in purified tubulin preparations, and identical behavior during various extraction procedures. CNP acts as a microtubule-associated protein in promoting microtubule assembly at low mole ratios. This activity resides in the C terminus of the enzyme, which, by itself, promotes microtubule assembly at higher mole ratios. Phosphorylation of CNP interferes with its assembly-promoting activity, as does deletion of the C terminus, which leads to abnormal microtubule distribution in the cell. Submembranous colocalization of the proteins and CNP-dependent microtubule organization suggest that CNP is a membrane-bound microtubule-associated protein that can link tubulin to membranes and may regulate cytoplasmic microtubule distribution.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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2',3'-Cyclic-Nucleotide Phosphodiesterases / chemistry*
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2',3'-Cyclic-Nucleotide Phosphodiesterases / metabolism
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2',3'-Cyclic-Nucleotide Phosphodiesterases / physiology*
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Amino Acid Sequence
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Animals
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Brain / cytology
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Cell Line
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Cell Membrane / metabolism
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Cytoplasm / chemistry
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Cytoplasm / metabolism
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DNA, Complementary / metabolism
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Electrophoresis, Polyacrylamide Gel
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Genetic Vectors
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Glutathione Transferase / metabolism
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Green Fluorescent Proteins
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Immunoblotting
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Luminescent Proteins / metabolism
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Microscopy, Fluorescence
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Microtubules / chemistry
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Microtubules / metabolism
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Molecular Sequence Data
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Phosphorylation
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Protein Binding
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Protein Structure, Tertiary
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Rats
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Recombinant Fusion Proteins / metabolism
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Subcellular Fractions
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Thyroid Gland / cytology
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Time Factors
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Transfection
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Tubulin / chemistry*
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Tubulin / metabolism
Substances
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DNA, Complementary
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Luminescent Proteins
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Recombinant Fusion Proteins
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Tubulin
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Green Fluorescent Proteins
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Glutathione Transferase
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2',3'-Cyclic-Nucleotide Phosphodiesterases