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Yeast Arf3p modulates plasma membrane PtdIns(4,5)P2 levels to facilitate endocytosis

Iwona I Smaczynska-de Rooij1, Rosaria Costa, Kathryn R Ayscough

  • 1Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK.

Traffic (Copenhagen, Denmark)
|January 23, 2008
PubMed

Insights

ADP ribosylation factor (Arf)3p regulates phosphatidylinositol-(4,5)-bisphosphate [PtdIns(4,5)P2] levels at the yeast plasma membrane. This finding reveals a novel mechanism impacting endocytosis.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Phosphatidylinositol-(4,5)-bisphosphate [PtdIns(4,5)P2] is crucial for endocytosis.
  • The kinase Mss4p generates PtdIns(4,5)P2 at the yeast plasma membrane.
  • The mechanism for Mss4p activation in endocytosis remains unclear.

Purpose of the Study:

  • To investigate the role of ADP ribosylation factor (Arf)3p in regulating PtdIns(4,5)P2 production.
  • To elucidate the mechanism of Arf3p-mediated PtdIns(4,5)P2 generation at the plasma membrane.
  • To understand the impact of Arf3p on endocytosis in yeast.

Main Methods:

  • Investigated Arf3p localization and its dependence on Gts1p and Yel1p.
  • Assessed PtdIns(4,5)P2 levels in yeast strains with altered Arf3p activity.
  • Quantified endocytic sites in relation to Arf3p levels.

Main Results:

  • Arf3p is essential for wild-type PtdIns(4,5)P2 levels at the plasma membrane.
  • Arf3p localization depends on Gts1p and Yel1p.
  • Reduced Arf3p decreases PtdIns(4,5)P2; increased Arf3p enhances PtdIns(4,5)P2 and endocytic sites.

Conclusions:

  • Arf3p positively regulates plasma membrane PtdIns(4,5)P2 production in yeast.
  • Arf3p acts in concert with endocytic machinery.
  • Arf3p-mediated PtdIns(4,5)P2 regulation impacts endocytosis.

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