title: Characterization of an A-kinase anchoring protein in human ciliary axonemes.
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.
authors.affiliation: Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Kultgen
authors.forename: Sherell K
authors.initials: SK
authors.lastname: Byrd
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Ostrowski
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Milgram
mesh_terms: D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; D000256:Adenoviridae / Q000235:genetics; D000595:Amino Acid Sequence; D001369:Axons / Q000378:metabolism; D001665:Binding Sites; D015152:Blotting, Northern; D001980:Bronchi / Q000166:cytology; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D002478:Cells, Cultured; D002923:Cilia / Q000378:metabolism*; D003001:Cloning, Molecular; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D015723:Gene Library; D005822:Genetic Vectors; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008164:Luminescent Proteins / Q000378:metabolism; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D054758:A Kinase Anchor Proteins; C475888:AKAP14 protein, human; D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018076:DNA, Complementary; D008164:Luminescent Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; C106837:testis-specific A-kinase-anchoring-protein, rat; D049452:Green Fluorescent Proteins; D005982:Glutathione Transferase; D017868:Cyclic AMP-Dependent Protein Kinases