A homologue of cysteine-rich secretory proteins induces premature degradation of vitelline envelopes and hatching of Xenopus laevis embryos.
We cloned Xenopus laevis CRISP, XCRISP, a homologue of the mammalian family of cysteine-rich secretory proteins (CRISPs), which has been previously identified as a Wnt3a/noggin responsive gene in an expression screen [Mech. Dev. 87 (1999) 21]. We detected XCRISP expression exclusively in the hatching gland. XCRISP enters the secretory pathway and accumulates on the surface of presumptive hatching gland cells. Overexpression studies of XCRISP and XCRISP-mutants show that XCRISP induces premature hatching of embryos preceded by degradation of the vitelline envelope. A deletion mutant that lacks a 35 amino acid domain even accelerates hatching, while further deletion of the carboxy-terminus reverses these effects. From our studies, we conclude that XCRISP is sufficient to induce degradation of vitelline envelopes and that this activity maps to the most C-terminal amino acids, while the adjacent domain regulates XCRISP activity.
Schambony
Alexandra
A
Institute of Zoology II, University of Karlsruhe, Fritz-Haber-Weg 4, D-76128 Karlsruhe, Germany. alexandra.schambony@zi2.uni-karlsruhe.de
Hefele
Jörg A
JA
Gentzel
Marc
M
Wilm
Matthias
M
Wedlich
Doris
D
D000595:Amino Acid Sequence; D000818:Animals; D004625:Embryo, Nonmammalian; D004627:Embryonic Induction; D018507:Gene Expression Regulation, Developmental; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014817:Vitelline Membrane / Q000378:metabolism*; D029867:Xenopus Proteins / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology*
D008562:Membrane Glycoproteins; D029867:Xenopus Proteins