title: Planar polarized protrusions break the symmetry of EGFR signaling during Drosophila bract cell fate induction.
abstract: Secreted signaling molecules typically float in the outer leaflet of the plasma membrane or freely diffuse away from the signaling cell, suggesting that a signal should be sensed equally by all neighboring cells. However, we demonstrate that Spitz (Spi)-mediated epidermal growth factor receptor (EGFR) signaling is spatially biased to selectively determine the induction of a single bract cell on the proximal side of each mechanosensory organ on the Drosophila leg. Dynamic and oriented cellular protrusions emanating from the socket cell, the source of Spi, robustly favor the Spi/EGFR signaling response in a particular cell among equally competent neighbors. We propose that these protrusive structures enhance signaling by increasing contact between the signaling and responding cells. The planar polarized direction of the protrusions determines the direction of the signaling outcome. This asymmetric cell signaling serves as a developmental mechanism to generate spatially patterned cell fates.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Peng
authors.forename: Chun
authors.initials: C
authors.lastname: Han
authors.forename: Jeffery D
authors.initials: JD
authors.lastname: Axelrod
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D016764:Cell Polarity; D022081:Cell Surface Extensions / Q000378:metabolism*; D004330:Drosophila / Q000166:cytology* / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029721:Drosophila Proteins; D008565:Membrane Proteins; C076026:spi protein, Drosophila; D004815:Epidermal Growth Factor; D066246:ErbB Receptors