Biosynthesis of frog skin mucins: cysteine-rich shuffled modules, polydispersities and genetic polymorphism.
1. Frog integumentary mucins (FIM-A.1, FIM-B.1 and FIM-C.1) consist of typical threonine-rich highly O-glycosylated (semi)repetitive domains, and cysteine-rich modules, i.e. the P-domain, the short consensus repeat and a region with high similarity to the C-terminal end of von Willebrand factor (designated here CC29-motif). 2. These modules are thought to be involved in protein-protein interactions and they have been observed in a variety of extracellular proteins. In FIMs, these modules may be involved in oligomerization processes leading to an entangled mucin network. 3. Polydispersities have been detected in FIM-B.1 and FIM-C.1 within single individuals. Multiple transcripts are probably generated by alternative splicing of a huge array of different (semi)repetitive cassettes encoding the threonine-rich domains. 4. Furthermore, genetic polymorphism is observed between different individuals, probably due to allelic variations in the number of (semi)repetitive cassettes.
Hoffmann
W
W
Max Planck-Institut für Psychiatrie, Abteilung Neurochemie, Martinsried, Federal Republic of Germany.
Hauser
F
F
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D003545:Cysteine / Q000032:analysis; D006031:Glycosylation; D008969:Molecular Sequence Data; D009077:Mucins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D011110:Polymorphism, Genetic; D012867:Skin / Q000378:metabolism*; D014982:Xenopus laevis / Q000378:metabolism*
D009077:Mucins; D003545:Cysteine