title: Induction of protein and glycoprotein synthesis in rat submandibular glands by isoproterenol.
abstract: A family of proline-rich proteins which contain over 40% proline and a glycoprotein were isolated from submandibular glands of isoproterenol-treated rats by extraction with 10% trichloroacetic acid and fractionation of the acid-soluble portion on Bio-Gel A-1.5m. The proline-rich proteins were subsequently separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were detected by formaldehyde fixation and Coomassie staining. After elution from the gels, amino acid compositions were determined. The family of proline-rich proteins (about six) appears to be qualitatively identical with a family of proteins from parotid glands of isoproterenol-treated rats (Muenzer J., Bildstein, C., Gleason, M., and Carlson, D. M. (1979) J. Biol. Chem. 254, 5623-5628, 5629-5634), except for a substantial change in the relative amount of each protein. An acid-soluble glycoprotein (GP-158) was not detected in extracts of submandibular glands of normal rats, but GP-158 was highly induced by isoproterenol treatment. This glycoprotein has an apparent Mr = 158,000 as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The major amino acids were Asx, 13%; Glx, 18%; Pro, 29% and Gly, 11%. GP-158 contained about 37% carbohydrate, and its sugar composition on a molar basis was mannose, 3.0; galactose, 2.1; N-acetylglucosamine, 3.5; fucose, 1.2; and sialic acid (N-glycolyl(4-O-acetyl)neuraminic acid), 0.9. N-Acetylgalactosamine was not detected. A glycopeptide isolated from GP-158 had the same sugar composition as GP-158. The amino acid sequence of the glycopeptide was shown to be Asp-Gly-(Asn)-Gln-Thr-Gln-Pro-Arg-Pro-(Gly-Pro). Only the parotid and submandibular glands of rats responded in this dramatic fashion to isoproterenol. The isoproterenol-treated rat is considered an appropriate model system for studying the overall effects of catecholamine beta-agonists on gene expression in these secretory tissues.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D006023:Glycoproteins / Q000096:biosynthesis*; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D010455:Peptides / Q000032:analysis; D011392:Proline / Q000378:metabolism; D055232:Proline-Rich Protein Domains; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D012995:Solubility; D013363:Submandibular Gland / Q000187:drug effects / Q000378:metabolism*; D014238:Trichloroacetic Acid
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D006023:Glycoproteins; D010455:Peptides; D014238:Trichloroacetic Acid; D011392:Proline; D007545:Isoproterenol