title: Discs-Large and Strabismus are functionally linked to plasma membrane formation.
abstract: During early embryogenesis in Drosophila melanogaster, extensive vesicle transport occurs to build cell boundaries for 6,000 nuclei. Here we show that this important process depends on a functional complex formed between the tumour suppressor and adaptor protein Discs-Large (Dlg) and the integral membrane protein Strabismus (Stbm)/Van Gogh (Vang). In support of this idea, embryos with mutations in either dlg or stbm displayed severe defects in plasma membrane formation. Conversely, overexpression of Dlg and Stbm synergistically induced excessive plasma membrane formation. In addition, ectopic co-expression of Stbm (which associated with post-Golgi vesicles) and the mammalian Dlg homologue SAP97/hDlg promoted translocation of SAP97 from the cytoplasm to both post-Golgi vesicles and the plasma membrane. This effect was dependent on the interaction between Stbm and SAP97. These findings suggest that the Dlg-Stbm complex recruits membrane-associated proteins and lipids from internal membranes to sites of new plasma membrane formation.
authors.affiliation: Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
authors.forename: Ok-Kyung
authors.initials: OK
authors.lastname: Lee
authors.forename: Kristopher K
authors.initials: KK
authors.lastname: Frese
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: James
authors.forename: Darshana
authors.initials: D
authors.lastname: Chadda
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Chen
authors.forename: Ronald T
authors.initials: RT
authors.lastname: Javier
authors.forename: Kyung-Ok
authors.initials: KO
authors.lastname: Cho
mesh_terms: D000818:Animals; D019556:COS Cells; D002462:Cell Membrane; D029721:Drosophila Proteins / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology / Q000502:physiology; D047108:Embryonic Development; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000502:physiology*; D009154:Mutation; D025521:Tumor Suppressor Proteins / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D029721:Drosophila Proteins; D008565:Membrane Proteins; D025521:Tumor Suppressor Proteins; C111638:Vang protein, Drosophila; C070350:dlg1 protein, Drosophila