The phosphoinositide phosphatase Sac1 regulates cell shape and microtubule stability in the developing Drosophila eye


Back to previous page
Authors: Del Bel, LM; Griffiths, N; Wilk, R; Wei, HC; Blagoveshchenskaya, A; Burgess, J; Polevoy, G; Price, JV; Mayinger, P; Brill, JA
Year: 2018
Journal: Development 145   Article Link (DOI)  PubMed
Title: The phosphoinositide phosphatase Sac1 regulates cell shape and microtubule stability in the developing Drosophila eye
Abstract: Epithelial patterning in the developing Drosophila melanogaster eye requires the Neph1 homolog Roughest (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. Sac1(ts) mutants have rough eyes and retinal patterning defects that resemble rst mutants. Sac1(ts) 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 Sac1(ts) mutants. However, Sac1(ts) 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.
Back to previous page
 


Departmental members may update their publication list.