ISSN:
1432-041X
Keywords:
Key words Cadherin
;
Catenin
;
Wnt signalling
;
Cell migration
;
pp120
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The Armadillo family is formed by proteins which possess an Arm domain comprising multiple copies of a 42-amino-acid motif, the Arm repeat, initially described for the Drosophila segment polarity gene product Armadillo. The Arm domain serves in protein-protein interactions which are required for the family members Armadillo, β-catenin and plakoglobin to mediate cell-cell adhesion and Wnt/Wingless signalling. Similarily, p120 cas , the Arm domain containing src substrate, also binds to cadherins and becomes tyrosine phosphorylated in response to a variety of stimuli. However, a putative function of p120 cas in adhesion or signalling has not yet been demonstrated. It has also not been shown until now that an Arm domain is a common signal transduction motif. Using Xenopus embryos we show by expression of murine p120 cas 1B (mp120 cas 1B) in ventral blastomeres that this catenin cannot replace β-catenin function in dorsal axis formation. Thus, the presence of an Arm domain per se is not sufficient to activate the Wnt/Wg pathway. Indeed, injection of mp120 cas 1B into dorsal blastomeres led instead to delayed blastopore closure and posteriorized phenotypes with malformed head structures indicative of disturbed gastrulation movements. Because neither convergent extension behaviour nor adhesion to fibronectin was altered in the injected embryos we assume that mp120 cas 1B influences motility or orientation of migrating mesodermal cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004270050138
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