title: The Drosophila Cadherin Fat regulates tissue size and planar cell polarity through different domains.
abstract: The Drosophila Cadherin Fat (Ft) has been identified as a crucial regulator of tissue size and Planar Cell Polarity (PCP). However, the precise mechanism by which Ft regulates these processes remains unclear. In order to advance our understanding of the action of Ft, we have sought to identify the crucial Ft effector domains. Here we report that a small region of the Ft cytoplasmic domain (H2 region) is both necessary and sufficient, when membrane localized, to support viability and prevent tissue overgrowth. Interestingly, the H2 region is dispensable for regulating PCP signaling, whereas the mutant Ft lacking the H2 region is fully capable of directing PCP. This result suggests that Ft's roles in PCP signaling and tissue size control are separable, and each can be carried out independently. Surprisingly, the crucial regions of Ft identified in our structure-function study do not overlap with the previously reported interaction regions with Atrophin, Dco, or Lowfat.
authors.affiliation: Department of Biology, Stanford University, Stanford, California, United States of America.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Zhao
authors.forename: Chung-Hui
authors.initials: CH
authors.lastname: Yang
authors.forename: Michael A
authors.initials: MA
authors.lastname: Simon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015820:Cadherins / Q000737:chemistry*; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D003593:Cytoplasm / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology* / Q000378:metabolism*; D005123:Eye / Q000166:cytology / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015398:Signal Transduction; D014022:Tissue Survival; D000099317:Hippo Kinases
chemical_list: D015820:Cadherins; D015815:Cell Adhesion Molecules; D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; C472307:ft protein, Drosophila; C093503:wts protein, Drosophila; C499474:hpo protein, Drosophila; D000099317:Hippo Kinases