Characterization of an A-kinase anchoring protein in human ciliary axonemes

Mol Biol Cell. 2002 Dec;13(12):4156-66. doi: 10.1091/mbc.e02-07-0391.


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

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • A Kinase Anchor Proteins
  • Adaptor Proteins, Signal Transducing*
  • Adenoviridae / genetics
  • Amino Acid Sequence
  • Axons / metabolism
  • Binding Sites
  • Blotting, Northern
  • Bronchi / cytology
  • Carrier Proteins* / chemistry*
  • Carrier Proteins* / metabolism
  • Cells, Cultured
  • Cilia / metabolism*
  • Cloning, Molecular
  • Cyclic AMP-Dependent Protein Kinases / chemistry
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • DNA, Complementary / metabolism
  • Epithelial Cells / metabolism
  • Gene Library
  • Genetic Vectors
  • Glutathione Transferase / metabolism
  • Green Fluorescent Proteins
  • HeLa Cells
  • Humans
  • Immunoblotting
  • Immunohistochemistry
  • Luminescent Proteins / metabolism
  • Membrane Proteins*
  • Molecular Sequence Data
  • Precipitin Tests
  • Protein Binding
  • Recombinant Fusion Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Time Factors
  • Tissue Distribution


  • A Kinase Anchor Proteins
  • AKAP14 protein, human
  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • DNA, Complementary
  • Luminescent Proteins
  • Membrane Proteins
  • Recombinant Fusion Proteins
  • testis-specific A-kinase-anchoring-protein, rat
  • Green Fluorescent Proteins
  • Glutathione Transferase
  • Cyclic AMP-Dependent Protein Kinases