PtdIns4P synthesis by PI4KIIIα at the plasma membrane and its impact on plasma membrane identity. Academic Article uri icon

Overview

abstract

  • Plasma membrane phosphatidylinositol (PI) 4-phosphate (PtdIns4P) has critical functions via both direct interactions and metabolic conversion to PI 4,5-bisphosphate (PtdIns(4,5)P₂) and other downstream metabolites. However, mechanisms that control this PtdIns4P pool in cells of higher eukaryotes remain elusive. PI4KIIIα, the enzyme thought to synthesize this PtdIns4P pool, is reported to localize in the ER, contrary to the plasma membrane localization of its yeast homologue, Stt4. In this paper, we show that PI4KIIIα was targeted to the plasma membrane as part of an evolutionarily conserved complex containing Efr3/rolling blackout, which we found was a palmitoylated peripheral membrane protein. PI4KIIIα knockout cells exhibited a profound reduction of plasma membrane PtdIns4P but surprisingly only a modest reduction of PtdIns(4,5)P₂ because of robust up-regulation of PtdIns4P 5-kinases. In these cells, however, much of the PtdIns(4,5)P₂ was localized intracellularly, rather than at the plasma membrane as in control cells, along with proteins typically restricted to this membrane, revealing a major contribution of PI4KIIIα to the definition of plasma membrane identity.

publication date

  • December 10, 2012

Research

keywords

  • Cell Membrane
  • Phosphatidylinositol Phosphates

Identity

PubMed Central ID

  • PMC3518224

Scopus Document Identifier

  • 85047686708

Digital Object Identifier (DOI)

  • 10.1016/j.bbamem.2007.03.026

PubMed ID

  • 23229899

Additional Document Info

volume

  • 199

issue

  • 6