Drosophila β Spectrin Functions Independently of α Spectrin to Polarize the Na,k Atpase in Epithelial Cells
| Autor: | Ping Wang, Ronald R. Dubreuil, Lawrence S.B. Goldstein, John Lee, Steve Dahl |
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| Rok vydání: | 2000 |
| Předmět: |
Ankyrins
Male X Chromosome ATPase Sodium-Potassium-Exchanging ATPase macromolecular substances plasma membrane 03 medical and health sciences Cell polarity Animals Ankyrin Spectrin Cytoskeleton 030304 developmental biology chemistry.chemical_classification 0303 health sciences biology Cell Membrane 030302 biochemistry & molecular biology Cell Polarity EPB41 cytoskeleton Cell Differentiation Epithelial Cells Cell Biology Cell biology Drosophila melanogaster Phenotype Microscopy Fluorescence chemistry Mutation biology.protein Original Article Drosophila Female Genes Lethal ATP synthase alpha/beta subunits |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| Popis: | Spectrin has been proposed to function as a sorting machine that concentrates interacting proteins such as the Na,K ATPase within specialized plasma membrane domains of polarized cells. However, little direct evidence to support this model has been obtained. Here we used a genetic approach to directly test the requirement for the beta subunit of the alphabeta spectrin molecule in morphogenesis and function of epithelial cells in Drosophila. beta Spectrin mutations were lethal during late embryonic/early larval development and they produced subtle defects in midgut morphology and stomach acid secretion. The polarized distributions of alphabeta(H) spectrin and ankyrin were not significantly altered in beta spectrin mutants, indicating that the two isoforms of Drosophila spectrin assemble independently of one another, and that ankyrin is upstream of alphabeta spectrin in the spectrin assembly pathway. In contrast, beta spectrin mutations had a striking effect on the basolateral accumulation of the Na,K ATPase. The results establish a role for beta spectrin in determining the subcellular distribution of the Na, K ATPase and, unexpectedly, this role is independent of alpha spectrin. |
| Databáze: | OpenAIRE |
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