Abstract
Although protein kinase A (PKA) activation is known to increase ciliary beat frequency in humans the molecular mechanisms involved are unknown. We demonstrate that PKA is associated with ciliary axonemes where it specifically phosphorylates a 23-kDa protein. Because PKA is often localized to subcellular compartments in proximity to its substrate(s) via interactions with A-kinase-anchoring proteins (AKAPs), we investigated whether an AKAP was also associated with ciliary axonemes. This study has identified a novel 28 kDa AKAP (AKAP28)that is highly enriched in airway axonemes. The mRNA for AKAP28 is up-regulated as primary airway cells differentiate and is specifically expressed in tissues containing cilia and/or flagella. Additionally, both Western blot and immunostaining data show that AKAP28 is enriched in airway cilia. These data demonstrate that we have identified the first human axonemal AKAP, a protein that likely plays a role in the signaling necessary for efficient modulation of ciliary beat frequency.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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A Kinase Anchor Proteins
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Adaptor Proteins, Signal Transducing*
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Adenoviridae / genetics
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Amino Acid Sequence
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Axons / metabolism
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Binding Sites
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Blotting, Northern
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Bronchi / cytology
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Carrier Proteins* / chemistry*
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Carrier Proteins* / metabolism
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Cells, Cultured
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Cilia / metabolism*
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Cloning, Molecular
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Cyclic AMP-Dependent Protein Kinases / chemistry
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Cyclic AMP-Dependent Protein Kinases / metabolism
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DNA, Complementary / metabolism
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Epithelial Cells / metabolism
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Gene Library
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Genetic Vectors
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Glutathione Transferase / metabolism
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Green Fluorescent Proteins
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HeLa Cells
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Humans
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Immunoblotting
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Immunohistochemistry
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Luminescent Proteins / metabolism
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Membrane Proteins*
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Molecular Sequence Data
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Precipitin Tests
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Protein Binding
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Recombinant Fusion Proteins / metabolism
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Sequence Homology, Amino Acid
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Time Factors
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Tissue Distribution
Substances
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A Kinase Anchor Proteins
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AKAP14 protein, human
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Adaptor Proteins, Signal Transducing
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Carrier Proteins
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DNA, Complementary
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Luminescent Proteins
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Membrane Proteins
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Recombinant Fusion Proteins
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testis-specific A-kinase-anchoring-protein, rat
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Green Fluorescent Proteins
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Glutathione Transferase
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Cyclic AMP-Dependent Protein Kinases