An unusual expression of a squamous cell marker, small proline-rich protein gene, in tracheobronchial epithelium: differential regulation and gene mapping.
An unusual expression of a putative squamous cell marker, small proline-rich protein (spr1), in mucociliary epithelial cells of conducting airways was demonstrated in a serum-free culture system. A cDNA clone was isolated from the cDNA library of monkey tracheobronchial epithelial (TBE) cells by differential hybridization. This cDNA clone, MT5, exhibited 98% homology to a DNA sequence obtained from human keratinocytes treated with either UV light or phorbol esters (T. Kartasova et al., 1988, Mol. Cell. Biol. 8:2195-2230). The predicted peptide of MT5 is unusual for its high content of proline (29%), glutamine (18%), and cysteine (9%) and its repeated PKVPEPC units. The level of spr1 mRNA in cultured cells was inhibited more than 90% by vitamin A. In contrast, phorbol 12-myristate 13-acetate (PMA) stimulated the level of spr1 mRNA by 3- to 8-fold. This differential regulation coincided with the effects of these chemicals on the cornification of cultured TBE cells. Using MT5 as a probe, we have localized the tracheal spr1 gene on the human chromosome 1 by a Southern blot analysis using a panel of human-rodent somatic cell hybrid DNAs. The gene was further sublocalized to bands q22-23 by in situ hybridization.
An
G
G
California Primate Research Center, University of California, Davis 95616.
Huang
T H
TH
Tesfaigzi
J
J
Garcia-Heras
J
J
Ledbetter
D H
DH
Carlson
D M
DM
Wu
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015415:Biomarkers; D015152:Blotting, Northern; D015139:Blotting, Southern; D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D055233:Cornified Envelope Proline-Rich Proteins; D004247:DNA; D004848:Epithelium / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007621:Karyotyping; D008253:Macaca mulatta; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014132:Trachea / Q000166:cytology / Q000378:metabolism*; D014801:Vitamin A / Q000494:pharmacology
D015415:Biomarkers; D055233:Cornified Envelope Proline-Rich Proteins; D008565:Membrane Proteins; D011506:Proteins; D014801:Vitamin A; D004247:DNA; D013755:Tetradecanoylphorbol Acetate