Tyrosine kinases, ankyrin repeats, and Src homology 2 domains play central roles in developmental processes. The cloning of a cDNA for Shark, a single protein that possesses all three domains, is described. During Drosophila embryogenesis, Shark is expressed exclusively by ectodermally derived epithelia and is localized preferentially to the apical surface of these cells. This apical localization persists, even as tissues undergo complex invaginations, moving from the external surface of embryos to form internal structures, but expression is lost when cells lose their polarity. This pattern closely mimics the expression of Crumbs, a protein necessary for proper organization of ectodermal epithelia. Shark's structure and localization pattern suggest that it functions in a signaling pathway for epithelial cell polarity, possibly transducing the Crumbs signal.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Mar 14 1995|
- signal transduction
ASJC Scopus subject areas