title: Conserved interactions with cytoskeletal but not signaling elements are an essential aspect of Drosophila WASp function.
abstract: Wiskott-Aldrich Syndrome proteins (WASp) serve as important regulators of cytoskeletal organization and function. These modular proteins, which are well-conserved among eukaryotic species, act to promote actin filament assembly in response to cues from various signal transduction pathways. Genetic analysis has revealed a requirement for the single Drosophila homolog, Wasp (Wsp), in cell-fate decisions governing specific neuronal lineages. We have used this unique developmental context to assess the contributions of established signaling and cytoskeletal partners of WASp. We present biochemical and genetic evidence that, as expected, Drosophila Wsp performs its developmental role via the Arp2/3 complex, indicating conservation of the cytoskeletal aspect of Wsp function in vivo. In contrast, we find that association with the key signaling molecules CDC42 and PIP2 is not an essential requirement, implying that activation of Wsp function in vivo depends on additional or alternative signaling pathways.
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Tamar
authors.initials: T
authors.lastname: Tal
authors.forename: Dalit
authors.initials: D
authors.lastname: Vaizel-Ohayon
authors.forename: Eyal D
authors.initials: ED
authors.lastname: Schejter
mesh_terms: D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins / Q000737:chemistry / Q000502:physiology; D000818:Animals; D001665:Binding Sites; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000502:physiology; D003599:Cytoskeleton / Q000502:physiology*; D029721:Drosophila Proteins / Q000737:chemistry* / Q000502:physiology; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology; D046911:Macromolecular Substances; D008465:Mechanoreceptors / Q000502:physiology*; D009024:Morphogenesis; D010641:Phenotype; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000502:physiology; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000502:physiology; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013045:Species Specificity; D013329:Structure-Activity Relationship; D051316:Wiskott-Aldrich Syndrome Protein; D020764:cdc42 GTP-Binding Protein / Q000502:physiology
chemical_list: D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; D046911:Macromolecular Substances; D019269:Phosphatidylinositol 4,5-Diphosphate; D011506:Proteins; D011993:Recombinant Fusion Proteins; D051316:Wiskott-Aldrich Syndrome Protein; D020764:cdc42 GTP-Binding Protein