title: Nak regulates Dlg basal localization in Drosophila salivary gland cells.
abstract: Protein trafficking is highly regulated in polarized cells. During development, how the trafficking of cell junctional proteins is regulated for cell specialization is largely unknown. In the maturation of Drosophila larval salivary glands (SGs), the Dlg protein is essential for septate junction formation. We show that Dlg was enriched in the apical membrane domain of proximal cells and localized basolaterally in distal mature cells. The transition of Dlg distribution was disrupted in nak mutants. Nak associated with the AP-2 subunit alpha-Ada and the AP-1 subunit AP-1gamma. In SG cells disrupting AP-1 and AP-2 activities, Dlg was enriched in the apical membrane. Therefore, Nak regulates the transition of Dlg distribution likely through endocytosis of Dlg from the apical membrane domain and transcytosis of Dlg to the basolateral membrane domain during the maturation of SGs development.
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan.
authors.forename: Yu-Huei
authors.initials: YH
authors.lastname: Peng
authors.forename: Wei-Kan
authors.initials: WK
authors.lastname: Yang
authors.forename: Wei-Hsiang
authors.initials: WH
authors.lastname: Lin
authors.forename: Tzu-Ting
authors.initials: TT
authors.lastname: Lai
authors.forename: Cheng-Ting
authors.initials: CT
authors.lastname: Chien
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D004705:Endocytosis; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012469:Salivary Glands / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D025521:Tumor Suppressor Proteins; C070350:dlg1 protein, Drosophila; C109770:Nak protein, Drosophila; D017346:Protein Serine-Threonine Kinases