Oncomodulin is abundant in the organ of Corti.
A small, acidic Ca(2+)-binding protein (CBP-15) was recently detected in extracts of the mammalian auditory receptor organ, the organ of Corti [Senarita et al. (1995) Hear. Res. 90, 169-175]. N-terminal sequence data for CBP-15 [Thalmann et al. (1995) Biochem. Biophys. Res. Commun. 215, 142-147] implied membership in the parvalbumin family and possible identity with the mammalian beta-parvalbumin oncomodulin. As shown herein, the latter conclusion is supported by strong cross-reactivity between CBP-15 and isoform-specific antibodies to oncomodulin. Moreover, we have succeeded in amplifying the guinea pig CBP-15 coding sequence from organ of Corti cDNA using degenerate oligonucleotide primers based on the rat oncomodulin sequence. The deduced amino acid sequence of guinea pig CBP-15 displays 90%, 92%, and 98% identity with mouse, rat, and human oncomodulin isoforms. Demonstration of the presence of oncomodulin in the organ of Corti is the first documentation of this substance in a postnatal mammalian tissue.
Henzl
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Biochemistry Department, University of Missouri at Columbia 65211, USA. bchenzl@muccmail.missouri.edu
Shibasaki
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O
Comegys
T H
TH
Thalmann
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Thalmann
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R
D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D001483:Base Sequence; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D007525:Isoelectric Focusing; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009841:Oligonucleotides / Q000378:metabolism; D009925:Organ of Corti / Q000378:metabolism*; D010320:Parvalbumins / Q000378:metabolism; D016133:Polymerase Chain Reaction; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D009363:Neoplasm Proteins; D009841:Oligonucleotides; D010320:Parvalbumins; D011994:Recombinant Proteins; C034733:oncomodulin