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Citation
Neuman, S.D., Bashirullah, A. (2018). Hobbit regulates intracellular trafficking to drive insulin-dependent growth during Drosophila development.  Development 145(11): dev161356.
FlyBase ID
FBrf0239138
Publication Type
Research paper
Abstract

All animals must coordinate growth rate and timing of maturation to reach the appropriate final size. Here, we describe hobbit, a novel and conserved gene identified in a forward genetic screen for Drosophila animals with small body size. hobbit is highly conserved throughout eukaryotes, but its function remains unknown. We demonstrate that hobbit mutant animals have systemic growth defects because they fail to secrete insulin. Other regulated secretion events also fail in hobbit mutant animals, including mucin-like 'glue' protein secretion from the larval salivary glands. hobbit mutant salivary glands produce glue-containing secretory granules that are reduced in size. Importantly, secretory granules in hobbit mutant cells lack essential membrane fusion machinery required for exocytosis, including Synaptotagmin 1 and the SNARE SNAP-24. These membrane fusion proteins instead accumulate inside enlarged late endosomes. Surprisingly, however, the Hobbit protein localizes to the endoplasmic reticulum. Our results suggest that Hobbit regulates a novel step in intracellular trafficking of membrane fusion proteins. Our studies also suggest that genetic control of body size, as a measure of insulin secretion, is a sensitive functional readout of the secretory machinery.

PubMed ID
PubMed Central ID
PMC6031322 (PMC) (EuropePMC)
Related Publication(s)
Personal communication to FlyBase

Location data for hob mutations.
Neuman and Bashirullah, 2018.8.23, Location data for hob mutations. [FBrf0239901]

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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Development
    Title
    Development
    Publication Year
    1987-
    ISBN/ISSN
    0950-1991
    Data From Reference