A Cytoplasmic GOLD Protein Controls Cell Polarity

Abstract

Phosphoinositide lipids provide spatial landmarks during polarized secretion.Here, we elucidate a role for phosphatidylinositol 4-phosphate (PI4P) metabolism in the control of cell polarity. In budding yeast, PI4P is enriched at the plasma membrane of growing daughter cells. Upon heat shock however, PI4P rapidly increases at the plasma membrane in mother cells resulting in a more uniform PI4P distribution. Rather than phosphoinositide kinase activation, PI4P hydrolysis is impaired to generate the heat-induced PI4P signal in mother cells. This fine tune control of PI4P metabolism is mediated through attenuation of the Osh3 protein that binds and presents PI4P to a phosphoinositide phosphatase.

A nanodomain anchored-scaffolding complex is required for PI4Kα function and localization in plants

“…Among many possibilities, they could correspond to ER-plasma membrane contact sites. Indeed, in yeast, Stt4 reside at these contacts (Omnus et al, 2018). Another hypothesis is that they could be a zone of attachment between the plasma membrane and the actin cytoskeleton.…”

Let it stick: Strategies and applications for intracellular plasma membrane targeting of proteins inSaccharomyces cerevisiae

“…Multiplex lipid binding domains can appear in homo‐tandems of PH domains such as in mammalian TAPP1 and TAPP2 (Li et al, 2013), as hetero‐tandems with other lipid binding domains such as the tandem PX‐PH domains in yeast Bem3p that cooperatively bind membrane lipids (Ali et al, 2018) or a combination of tandem PH domains and additional motifs such as for human ARAP3 (Craig et al, 2010). Tandem configurations of PH domains that appear naturally as single domains were artificially created for rat and human PH PLCδ1 (GFP‐2xPH PLCδ1 ) and tested in yeast (Fairn et al, 2011; Mioka et al, 2020; Omnus et al, 2018; Rodríguez‐Escudero et al, 2018; Thomas et al, 2022; Wild et al, 2004). In direct comparison to GFP‐PH PLCδ1 , GFP‐2xPH PLCδ1 showed that previously weak PM binding with high levels of cytosolic localization was shifted to strong PM targeting in yeast (Levine & Munro, 2002; Wild et al, 2004).…”