title: Ankyrin-G palmitoylation and βII-spectrin binding to phosphoinositide lipids drive lateral membrane assembly.
abstract: Ankyrin-G and βII-spectrin colocalize at sites of cell-cell contact in columnar epithelial cells and promote lateral membrane assembly. This study identifies two critical inputs from lipids that together provide a rationale for how ankyrin-G and βII-spectrin selectively localize to Madin-Darby canine kidney (MDCK) cell lateral membranes. We identify aspartate-histidine-histidine-cysteine 5/8 (DHHC5/8) as ankyrin-G palmitoyltransferases required for ankyrin-G lateral membrane localization and for assembly of lateral membranes. We also find that βII-spectrin functions as a coincidence detector that requires recognition of both ankyrin-G and phosphoinositide lipids for its lateral membrane localization. DHHC5/8 and βII-spectrin colocalize with ankyrin-G in micrometer-scale subdomains within the lateral membrane that are likely sites for palmitoylation of ankyrin-G. Loss of either DHHC5/8 or ankyrin-G-βII-spectrin interaction or βII-spectrin-phosphoinositide recognition through its pleckstrin homology domain all result in failure to build the lateral membrane. In summary, we identify a functional network connecting palmitoyltransferases DHHC5/8 with ankyrin-G, ankyrin-G with βII-spectrin, and βII-spectrin with phosphoinositides that is required for the columnar morphology of MDCK epithelial cells.
authors: Department of Pharmacology and Cancer Biology, Department of Cell Biology, Department of Biochemistry, and Department of Neurobiology, Duke University Medical Center, Durham, NC 27710.
authors: Meng
authors: M
authors: He
authors: Department of Pharmacology and Cancer Biology, Department of Cell Biology, Department of Biochemistry, and Department of Neurobiology, Duke University Medical Center, Durham, NC 27710.
authors: Khadar M
authors: KM
authors: Abdi
authors: Department of Pharmacology and Cancer Biology, Department of Cell Biology, Department of Biochemistry, and Department of Neurobiology, Duke University Medical Center, Durham, NC 27710Department of Pharmacology and Cancer Biology, Department of Cell Biology, Department of Biochemistry, and Department of Neurobiology, Duke University Medical Center, Durham, NC 27710 Howard Hughes Medical Institute, Durham, NC 27710 vann.bennett@duke.edu.
authors: Vann
authors: V
authors: Bennett
mesh_terms: D000818:Animals; D017487:Ankyrins / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D055785:Gene Knockdown Techniques; D054878:Lipoylation; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D008954:Models, Biological; D010716:Phosphatidylinositols / Q000378:metabolism*; D013049:Spectrin / Q000032:analysis / Q000378:metabolism* / Q000502:physiology
chemical_list: D017487:Ankyrins; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D013049:Spectrin