A novel phosphatidylinositol(3,4,5)P3 pathway in fission yeast Academic Article uri icon

Overview

MeSH Major

  • Phosphatidylinositol Phosphates
  • Phosphoric Monoester Hydrolases
  • Schizosaccharomyces
  • Schizosaccharomyces pombe Proteins

abstract

  • The mammalian tumor suppressor, phosphatase and tensin homologue deleted on chromosome 10 (PTEN), inhibits cell growth and survival by dephosphorylating phosphatidylinositol-(3,4,5)-trisphosphate (PI[3,4,5]P3). We have found a homologue of PTEN in the fission yeast, Schizosaccharomyces pombe (ptn1). This was an unexpected finding because yeast (S. pombe and Saccharomyces cerevisiae) lack the class I phosphoinositide 3-kinases that generate PI(3,4,5)P3 in higher eukaryotes. Indeed, PI(3,4,5)P3 has not been detected in yeast. Surprisingly, upon deletion of ptn1 in S. pombe, PI(3,4,5)P3 became detectable at levels comparable to those in mammalian cells, indicating that a pathway exists for synthesis of this lipid and that the S. pombe ptn1, like mammalian PTEN, suppresses PI(3,4,5)P3 levels. By examining various mutants, we show that synthesis of PI(3,4,5)P3 in S. pombe requires the class III phosphoinositide 3-kinase, vps34p, and the phosphatidylinositol-4-phosphate 5-kinase, its3p, but does not require the phosphatidylinositol-3-phosphate 5-kinase, fab1p. These studies suggest that a pathway for PI(3,4,5)P3 synthesis downstream of a class III phosphoinositide 3-kinase evolved before the appearance of class I phosphoinositide 3-kinases.

publication date

  • July 19, 2004

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC2172303

Digital Object Identifier (DOI)

  • 10.1083/jcb.200404150

PubMed ID

  • 15249580

Additional Document Info

start page

  • 205

end page

  • 11

volume

  • 166

number

  • 2