title: Drosophila aPKC regulates cell polarity and cell proliferation in neuroblasts and epithelia.
abstract: Cell polarity is essential for generating cell diversity and for the proper function of most differentiated cell types. In many organisms, cell polarity is regulated by the atypical protein kinase C (aPKC), Bazooka (Baz/Par3), and Par6 proteins. Here, we show that Drosophila aPKC zygotic null mutants survive to mid-larval stages, where they exhibit defects in neuroblast and epithelial cell polarity. Mutant neuroblasts lack apical localization of Par6 and Lgl, and fail to exclude Miranda from the apical cortex; yet, they show normal apical crescents of Baz/Par3, Pins, Inscuteable, and Discs large and normal spindle orientation. Mutant imaginal disc epithelia have defects in apical/basal cell polarity and tissue morphology. In addition, we show that aPKC mutants show reduced cell proliferation in both neuroblasts and epithelia, the opposite of the lethal giant larvae (lgl) tumor suppressor phenotype, and that reduced aPKC levels strongly suppress most lgl cell polarity and overproliferation phenotypes.
authors.affiliation: Institutes of Neuroscience and Molecular Biology, Howard Hughes Medical Institute, 1254 University of Oregon, Eugene, OR 97403, USA.
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Rolls
authors.forename: Roger
authors.initials: R
authors.lastname: Albertson
authors.forename: Hsin-Pei
authors.initials: HP
authors.lastname: Shih
authors.forename: Cheng-Yu
authors.initials: CY
authors.lastname: Lee
authors.forename: Chris Q
authors.initials: CQ
authors.lastname: Doe
mesh_terms: D000483:Alleles; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000502:physiology*; D016764:Cell Polarity; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins; D007814:Larva / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D010641:Phenotype; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; C107613:Mira protein, Drosophila; D025521:Tumor Suppressor Proteins; C400774:baz protein, Drosophila; C081435:l(2)gl protein, Drosophila; C115015:PKC-3 protein; D011493:Protein Kinase C