Topic
Subapical complex
About: Subapical complex is a research topic. Over the lifetime, 5 publications have been published within this topic receiving 481 citations.
Papers
TL;DR: Two different Stardust proteins are introduced here: one MAGUK protein, characterized by a PDZ domain, an SH3 domain and a guanylate kinase domain; and a second isoform comprising only the guanylation domain, which represents versatile candidates as structural and possibly regulatory constituents of the SAC, a crucial element in the control of epithelial cell polarity.
Abstract: The polarized architecture of epithelial cells depends on the highly stereotypic distribution of cellular junctions and other membrane-associated protein complexes. In epithelial cells of the Drosophila embryo, three distinct domains subdivide the lateral plasma membrane. The most apical one comprises the subapical complex (SAC). It is followed by the zonula adherens (ZA) and, further basally, by the septate junction1. A core component of the SAC is the transmembrane protein Crumbs, the cytoplasmic domain of which recruits the PDZ-protein Discs Lost into the complex2,3. Cells lacking crumbs or the functionally related gene stardust fail to organize a continuous ZA and to maintain cell polarity4,5,6. Here we show that stardust provides an essential component of the SAC. Stardust proteins colocalize with Crumbs and bind to the carboxy-terminal amino acids of its cytoplasmic tail. We introduce two different Stardust proteins here: one MAGUK protein, characterized by a PDZ domain, an SH3 domain and a guanylate kinase domain; and a second isoform comprising only the guanylate kinase domain. The Stardust proteins represent versatile candidates as structural and possibly regulatory constituents of the SAC, a crucial element in the control of epithelial cell polarity.
306 citations
TL;DR: It is shown that the lateral membranes of the cells of the stratum granulosum are connected by an extended subapical complex system integrating desmosomes and TJ structures identified as sites of close membrane- Membrane contact and as regions of membrane-to-membrane apposition that in immunoelectron microscopy are positive for TJ markers, indicative of an extended, probably continuous TJ barrier.
90 citations
TL;DR: An overview of three major molecular complexes at the apical surface of epithelial cells in the C. elegans embryo, which discusses how the assembly of these complexes contributes to epithelial polarity and adhesion, proteins that act as effectors and/or regulators of each subdomain, and how these complexes functionally interact during embryonic morphogenesis.
Abstract: The epithelial tissues of the C. elegans embryo provide a "minimalist" system for examining phylogenetically conserved proteins that function in epithelial polarity and cell-cell adhesion in a multicellular organism. In this review, we provide an overview of three major molecular complexes at the apical surface of epithelial cells in the C. elegans embryo: the cadherin-catenin complex, the more basal DLG-1/AJM-1 complex, and the apical membrane domain, which shares similarities with the subapical complex in Drosophila and the PAR/aPKC complex in vertebrates. We discuss how the assembly of these complexes contributes to epithelial polarity and adhesion, proteins that act as effectors and/or regulators of each subdomain, and how these complexes functionally interact during embryonic morphogenesis. Although much remains to be clarified, significant progress has been made in recent years to clarify the role of these protein complexes in epithelial morphogenesis, and suggests that C. elegans will continue to be a fruitful system in which to elucidate functional roles for these proteins in a living embryo.
49 citations
TL;DR: This review will explore the links between growth and apical junction proteins in the regulation of growth control in Drosophila.
10 citations
TL;DR: The results suggest that juxtacrine signaling in epithelia generally depends on the apicobasally polarized structure of epithelial cells, and N, but not Dl, formed a specific complex with DEcad in vivo.
Abstract: Notch (N) and its ligands, Delta (Dl) and Serrate (Ser), are transmembrane proteins that mediate the cell‐cell interactions necessary for many cell-fate decisions. In Drosophila , N is predominantly localized to the apical portion of epithelial cells, but the mechanisms and functions of this localization are unknown. Here, we found N, Dl, and Ser were mostly located in the region from the subapical complex (SAC) to the apical portion of the adherens junctions (AJs) in wing disc epithelium. N was delivered to the SAC/AJs in two phases. First, polarized exocytosis specifically delivered nascent N to the apical plasma membrane and AJs in an O -fut1-independent manner. Second, N at the plasma membrane was relocated to the SAC/AJs by Dynamin- and Rab5dependent transcytosis; this step required the O -fut1 function. Disruption of the apical polarity by Drosophila E-cadherin ( D Ecad) knock down caused N and Dl localization to the SAC/AJs to fail. N, but not Dl, formed a specific complex with D Ecad in vivo . Finally, our results suggest that juxtacrine signaling in epithelia generally depends on the apicobasally polarized structure of epithelial cells.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2009 | 2 |
| 2007 | 1 |
| 2004 | 1 |
| 2001 | 1 |