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Hatori, R.

Publications and source records attributed to Hatori, R..

5 recordsLinked to original sources

Smoothened turnover regulated by Hedgehog signaling in Drosophila

During development, the processes of cell-cell signaling orchestrate growth and morphogenesis using both static features and moving parts. For example, expression domains of genes which set states of determination may be fixed in space for periods of time, but multiple signals move between the determined cells and intracellular movements of components of the signal transduction machines are key to information exchange. In the Drosophila wing imaginal disc, Hedgehog (Hh) protein produced in the posterior compartment moves to cells across the anterior/posterior compartment border to induce signal transduction and various intracellular responses. In this work, we investigated protein turnover and intracellular trafficking of components of Hh signal transduction in the wing disc and found that both are major features of Hh signaling. SummaryThe intracellular distribution and half-life of Smoothened is regulated by Hedgehog signaling.

developmental biology↗

The Drosophila AWP1 ortholog Doctor No regulates JAK/STAT signaling for left-right asymmetry in the gut by promoting receptor endocytosis

Many internal Drosophila organs show stereotypical left-right (LR) asymmetry, for which the underlying mechanisms remain elusive. Here, we identified an evolutionarily conserved ubiquitin-binding protein, AWP1/Doctor no (Drn), as a novel factor required for the LR asymmetry of the embryonic anterior gut in Drosophila. We showed that drn is essential in the circular visceral muscle cells of the midgut for JAK/STAT signaling, which contributes to the first known cue for anterior gut lateralization via LR-asymmetric nuclear rearrangement. Embryos homozygous for drn and lacking its maternal contribution showed phenotypes similar to that of depleted JAK/STAT signaling, suggesting that Drn is a general component of JAK/STAT signaling. The absence of Drn resulted in the specific accumulation of Domeless (Dome), the receptor of JAK/STAT signaling, in intracellular compartments. Thus, Drn is required for the endocytic trafficking of Dome, which is subsequently degraded in lysosomes. Our results suggest that the endocytosis of Dome is a critical step in activating JAK/STAT signaling. The roles of AWP1/Drn in activating JAK/STAT signaling and in LR-asymmetric development may be conserved in various organisms. Summary StatementDr. No, a Drosophila ortholog of AWP1, activates JAK/STAT signaling via Dome receptor endocytosis in a crucial step for left-right asymmetry in the developing gut.

developmental biology↗

Regulated delivery controls Drosophila Hedgehog, Wingless and Decapentaplegic signaling

Morphogen signaling proteins disperse across tissues to activate signal transduction in target cells. We investigated dispersion of Hedgehog (Hh), Wingless (Wg), and Bone morphogenic protein homolog Decapentaplegic (Dpp) in the Drosophila wing imaginal disc, and found that delivery to targets is regulated. Cells take up <5% Hh produced, and neither amounts taken up nor extent of signaling changes under conditions of Hh production from 50-200% normal amounts. Similarly, cells take up <25% Wg produced, and variation in Wg production from 50-700% normal has no effect on amounts taken up or signaling. Similar properties were observed for Dpp. Wing disc-produced Hh signals to disc-associated tracheal and myoblast as well as an approximately equal number of disc cells, but the extent of signaling in the disc is unaffected by the presence or absence of the tracheal cells and myoblasts. These findings show that target cells do not take up signaling proteins from a common pool and that both the amount and destination of delivered morphogens are regulated.. SummaryThe extent of Hh, Wg, and Dpp signaling is independent of the amount of signal produced or the number of recipient cells.

developmental biology↗

Hedgehog produced by the Drosophila wing imaginal disc induces distinct expression responses in three target tissues

Hedgehog (Hh) is an evolutionarily conserved signaling protein that has essential roles in animal development and homeostasis. We investigated Hh signaling in the region of the Drosophila wing imaginal disc that produces Hh and is near the tracheal air sac primordium (ASP) and myoblasts. Hh distributes in concentration gradients in the wing disc anterior compartment, ASP, and myoblasts and activates different sets of genes in each tissue. Some transcriptional targets of Hh signal transduction are common to the disc, ASP, and myoblasts, whereas others are tissue-specific. Signaling in the three tissues is cytoneme-mediated and cytoneme-dependent. We conclude that a single source of Hh in the wing disc regulates cell type-specific responses in three discreet target tissues. SummaryHedgehog produced by the wing imaginal disc signals to wing disc, myoblast and tracheal cells

developmental biology↗

Cytoneme-mediated signaling essential for tumorigenesis

Communication between neoplastic cells and cells of their microenvironment is critical to cancer progression. To investigate the role of cytoneme-mediated signaling as a mechanism for distributing growth factor signaling proteins between tumor and tumor-associated cells, we analyzed EGFR and RET Drosophila tumor models. We tested several genetic loss-of-function conditions that impair cytoneme-mediated signaling. diaphanous, Neuroglian, SCAR, capricious are genes that cytonemes require during normal development. Genetic inhibition of cytonemes restored apical basal polarity to tumor cells, reduced tumor growth, and increased organism survival. These findings suggest that cytonemes traffic the signaling proteins that move between tumor and stromal cells, and that cytoneme-mediated signaling is required for tumor growth and malignancy.\n\nSummaryEssential cytonemes for paracrine signaling in Drosophila tumors

cancer biology↗