The phosphoinositide phosphatase sac1 regulates cell shape and microtubule stability in the developing drosophila eye

Lauren M. Del Bel, Nigel Griffiths, Ronit Wilk, Ho Chun Wei, Anastasia Blagoveshchenskaya, Jason Burgess, Gordon Polevoy, James V. Price, Peter Mayinger, Julie A. Brill

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1 Scopus citations

Abstract

Epithelial patterning in the developing Drosophila melanogaster eye requires the Neph1 homologRoughest (Rst), an immunoglobulin family cell surface adhesion molecule expressed in interommatidial cells (IOCs). Here, using a novel temperature-sensitive (ts) allele, we show that the phosphoinositide phosphatase Sac1 is also required for IOC patterning. Sac1ts mutants have rough eyes and retinal patterning defects that resemble rst mutants. Sac1ts retinas exhibit elevated levels of phosphatidylinositol 4-phosphate (PI4P), consistent with the role of Sac1 as a PI4P phosphatase. Indeed, genetic rescue and interaction experiments reveal that restriction of PI4P levels by Sac1 is crucial for normal eye development. Rst is delivered to the cell surface in Sac1ts mutants. However, Sac1ts mutant IOCs exhibit severe defects in microtubule organization, associated with accumulation of Rst and the exocyst subunit Sec8 in enlarged intracellular vesicles upon cold fixation ex vivo. Together, our data reveal a novel requirement for Sac1 in promoting microtubule stability and suggest that Rst trafficking occurs in a microtubule- and exocyst-dependent manner.

Original languageEnglish (US)
Article numberdev151571
JournalDevelopment (Cambridge)
Volume145
Issue number11
DOIs
StatePublished - Jun 1 2018

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Keywords

  • Drosophila
  • Exocyst
  • IRM protein
  • Phosphatidylinositol 4-phosphate
  • PI4KII
  • PtdIns(4)P
  • Sac1

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology

Cite this

Del Bel, L. M., Griffiths, N., Wilk, R., Wei, H. C., Blagoveshchenskaya, A., Burgess, J., Polevoy, G., Price, J. V., Mayinger, P., & Brill, J. A. (2018). The phosphoinositide phosphatase sac1 regulates cell shape and microtubule stability in the developing drosophila eye. Development (Cambridge), 145(11), [dev151571]. https://doi.org/10.1242/dev.151571