Asymmetric homotypic interactions of the atypical cadherin flamingo mediate intercellular polarity signaling.

TitleAsymmetric homotypic interactions of the atypical cadherin flamingo mediate intercellular polarity signaling.
Publication TypeJournal Article
Year of Publication2008
AuthorsChen W-S, Antic D, Matis M, Logan CY, Povelones M, Anderson GA, Nusse R, Axelrod JD
JournalCell
Volume133
Pagination1093–1105
Date PublishedJun
ISSN1097-4172 (Electronic); 0092-8674 (Linking)
AbstractAcquisition of planar cell polarity (PCP) in epithelia involves intercellular communication, during which cells align their polarity with that of their neighbors. The transmembrane proteins Frizzled (Fz) and Van Gogh (Vang) are essential components of the intercellular communication mechanism, as loss of either strongly perturbs the polarity of neighboring cells. How Fz and Vang communicate polarity information between neighboring cells is poorly understood. The atypical cadherin, Flamingo (Fmi), is implicated in this process, yet whether Fmi acts permissively as a scaffold or instructively as a signal is unclear. Here, we provide evidence that Fmi functions instructively to mediate Fz-Vang intercellular signal relay, recruiting Fz and Vang to opposite sides of cell boundaries. We propose that two functional forms of Fmi, one of which is induced by and physically interacts with Fz, bind each other to create cadherin homodimers that signal bidirectionally and asymmetrically, instructing unequal responses in adjacent cell membranes to establish molecular asymmetry.
DOI10.1016/j.cell.2008.04.048