Loss of Fat4 disrupts PCP signaling and oriented cell division and leads to cystic kidney disease.
Tissue organization in Drosophila is regulated by the core planar cell polarity (PCP) proteins Frizzled, Dishevelled, Prickle, Van Gogh and Flamingo. Core PCP proteins are conserved in mammals and function in mammalian tissue organization. Recent studies have identified another group of Drosophila PCP proteins, consisting of the protocadherins Fat and Dachsous (Ds) and the transmembrane protein Four-jointed (Fj). In Drosophila, Fat represses fj transcription, and Ds represses Fat activity in PCP. Here we show that Fat4 is an essential gene that has a key role in vertebrate PCP. Loss of Fat4 disrupts oriented cell divisions and tubule elongation during kidney development, leading to cystic kidney disease. Fat4 genetically interacts with the PCP genes Vangl2 and Fjx1 in cyst formation. In addition, Fat4 represses Fjx1 expression, indicating that Fat signaling is conserved. Together, these data suggest that Fat4 regulates vertebrate PCP and that loss of PCP signaling may underlie some cystic diseases in humans.
Saburi
Sakura
S
Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto M5G 1X5, Canada.
Hester
Ian
I
Fischer
Evelyne
E
Pontoglio
Marco
M
Eremina
Vera
V
Gessler
Manfred
M
Quaggin
Sue E
SE
Harrison
Robert
R
Mount
Richard
R
McNeill
Helen
H
D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D016764:Cell Polarity; D004331:Drosophila melanogaster; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D007668:Kidney / Q000196:embryology*; D052177:Kidney Diseases, Cystic / Q000378:metabolism*; D051379:Mice
D015820:Cadherins; C506555:Fat4 protein, mouse