Expression of spasmolysin (FIM-A.1): an integumentary mucin from Xenopus laevis
Research output: Contribution to journal › Journal article › Research › peer-review
In the past, a unique type of precursor for a secretory protein was discovered. It contains a central repetitive domain rich in threonine residues and terminal cysteine-rich domains. Due to striking homologies of these terminal domains with pancreatic spasmolytic polypeptide, originally the name "prepro-spasmolysin" was proposed. Here we show that the mature protein has a MW of about 130 kDa, consisting of about 70% carbohydrate and 30% protein. Similar O-linked glycoproteins have been found in mucins from human intestine. For this and numerous other reasons we decided to rename this glycoprotein "frog integumentary mucin A.1" (FIM-A.1). Furthermore, analysis of the protein with specific antibodies against the predicted C-terminal end indicates that FIM-A.1 is probably not processed at pairs of basic residues. In situ hybridization as well as immunofluorescence studies revealed that FIM-A.1 is expressed and stored exclusively in mature mucous glands of Xenopus laevis skin. Only cone cells at the proximal part of these glands do not synthesize FIM-A.1. In contrast, all other physiologically active peptides from X. laevis skin investigated so far are synthesized in granular glands. A hypothetical function of FIMs for defense against microbial infections is discussed.
Original language | English |
---|---|
Journal | Experimental Cell Research |
Volume | 189 |
Issue number | 2 |
Pages (from-to) | 157-62 |
Number of pages | 6 |
ISSN | 0014-4827 |
DOIs | |
Publication status | Published - Aug 1990 |
- Amino Acid Sequence, Animals, Base Sequence, Electrophoresis, Polyacrylamide Gel, Fluorescent Antibody Technique, Immune Sera, Molecular Sequence Data, Molecular Weight, Mucins/analysis, Mucous Membrane/cytology, Oligonucleotide Probes, Oligopeptides/chemical synthesis, Recombinant Fusion Proteins/analysis, Skin/cytology, Xenopus Proteins, Xenopus laevis
Research areas
ID: 347886198