Dermal glands of Xenopus laevis contain a polypeptide with a highly repetitive amino acid sequence

• Published in: FEBS letters Vol. 260; no. 1; pp. 145 - 148
• Main Authors: Gmachl, Michael, Berger, Hans, Thalhammer, Josef, Kreil, Günther
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.1990; Elsevier
• Subjects: Amino Acid Sequence; Amphibian skin; Animals; Biological and medical sciences; cDNA cloning; Cloning, Molecular; DNA - analysis; Exocrine Glands - metabolism; Fundamental and applied biological sciences. Psychology; Genes. Genome; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Nucleotide sequence; Peptides - analysis; Peptides - genetics; Peptides - metabolism; Repetitive Sequences, Nucleic Acid; SDS-PAGE; SDS-polyacrylamide gel electrophoresis; Secretory gland; skin; Xenopus laevis - metabolism; SDS-PAGE; cDNA cloning; Secretory gland; Nucleotide sequence; Amphibian skin; Amino acid sequence; SDS-polyacrylamide gel electrophoresis; Vertebrata; Complementary DNA; Polypeptide; Repeated sequence; Xenopus laevis; Amphibia; Exocrine gland; Salientia; Skin; Molecular cloning; Aminoacid sequence
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(90)80088-Z

Mature dermal glands of Xenopus laevis contain storage granules with a characteristic ellipsoid shape. These granules contain, as a minor component, a heat-stable, acidic polypeptide with an apparent molecular mass of 75 kDa. Using antibodies against this protein, positive clones were isolated from a cDNA expression library prepared from skin of X. leaevis. One of the cloned cDNAs encodes a pre-protein with a typical signal sequence and a mature part of 396 amino acids. The protein contains 33 copies of the sequence Gly-Gly/Glu-(Ala-Pro) 2–4-Ala-Glu. Using the single-letter code for the four predominant amino acids, we have termed this polypeptide the APEG protein. Near its carboxy-terminus, one segment has been found with an amino acid sequence similar to that of spasmolytic polypeptide from porcine pancreas and to the human protein pS2.