Similarities of integumentary mucin B.1 from Xenopus laevis and prepro-von Willebrand factor at their amino-terminal regions.
Frog integumentary mucin B.1 (FIM-B.1) contains various cysteine-rich modules. In the past, a COOH-terminal "cystine knot" motif has been found that is similar to von Willebrand factor; this region is generally known to be responsible for dimerization processes. Furthermore, a "complement control protein" motif is present as an internal cysteine-rich domain in FIM-B.1. We characterize here the missing 75% toward the NH2 terminus of the FIM-B.1 precursor by molecular cloning. Analogous to prepro-von Willebrand factor, four elements with considerable similarity to D-domains are present (i.e. D1-D2-D'-D3). These domains have been described as essential for the multimerization of von Willebrand factor. Thus, the general structure of FIM-B.1 resembles that of the human mucin MUC2 as well as prepro-von Willebrand factor; these three molecules at least seem to share common structural elements allowing similar multimerization mechanisms.
Joba
W
W
Max-Planck-Institut für Psychiatrie, Abteilung Neurochemie, D-82152 Martinsried, Germany.
Hoffmann
W
W
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D008969:Molecular Sequence Data; D009077:Mucins / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D029867:Xenopus Proteins; D014982:Xenopus laevis; D014841:von Willebrand Factor / Q000235:genetics*
D018076:DNA, Complementary; C065866:MUC19 protein, Xenopus; D009077:Mucins; D011498:Protein Precursors; D029867:Xenopus Proteins; D014841:von Willebrand Factor; C050818:prepro-von Willebrand factor