Identification with a recombinant antibody of an inner-ear cytokeratin, a marker for hair-cell differentiation.
Extensive biochemical characterization of cells in the inner ear has been hampered by a lack of tools with which to identify inner-ear proteins. By using a single-chain antibody fragment isolated from a bacteriophage-displayed library, we have identified a cytokeratin that is abundant in nonsensory cells of the frog inner ear. Although the progenitors of hair cells exhibit strong immunoreactivity to this cytokeratin, the signal declines in immature hair cells and vanishes as the cells mature. The correlation between diminished immunoreactivity and hair-cell differentiation indicates that the cytokeratin is down-regulated during the transition from a nonsensory to a sensory cell and suggests that the marker is an early index of hair-cell differentiation.
Cyr
J L
JL
Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA.
Bell
A M
AM
Hudspeth
A J
AJ
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001483:Base Sequence; D015415:Biomarkers / Q000032:analysis; D002454:Cell Differentiation; D007758:Ear, Inner / Q000166:cytology* / Q000502:physiology; D000939:Epitopes / Q000032:analysis; D006199:Hair Cells, Auditory, Inner / Q000166:cytology* / Q000502:physiology; D007633:Keratins / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D009928:Organ Specificity; D019151:Peptide Library; D011892:Rana catesbeiana; D011994:Recombinant Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D000906:Antibodies; D015415:Biomarkers; D000939:Epitopes; D009838:Oligodeoxyribonucleotides; D019151:Peptide Library; D011994:Recombinant Proteins; D007633:Keratins