Characterization of the bovine brain cytosolic phosphatidylinositol 3-kinase complex

  1. Ruiz-Larrea, F. 1
  2. Vicendo, P. 1
  3. Yaish, P. 1
  4. End, P. 1
  5. Panayotou, G. 1
  6. Fry, M.J. 1
  7. Morgan, S.J. 1
  8. Thompson, A. 1
  9. Parker, P.J. 1
  10. Waterfield, M.D. 1
  1. 1 Ludwig Institute for Cancer Research, 91 Riding House Street, London W1P 8BT, United Kingdom
Revista:
Biochemical Journal

ISSN: 0264-6021

Año de publicación: 1993

Volumen: 290

Número: 2

Páginas: 609-616

Tipo: Artículo

PMID: 8383968 SCOPUS: 2-s2.0-0027450288 GOOGLE SCHOLAR

Otras publicaciones en: Biochemical Journal

Resumen

Receptor-linked phosphatidylinositol (PtdIns) 3-kinase may generate a second-messenger signal. Here a large-scale purification of the bovine brain enzyme, based on methods developed by Morgan, Smith and Parker and Fry, Panayotou, Dhand, Ruiz-Larrea, Gout, Nguyen, Courtneidge and Waterfield is described. The purified enzyme is shown to be a heterodimer of 85 kDa and 110 kDa protein subunits (p85 and p110). Labelling with 5'-p-fluorosulphonylbenzoyladenosine shows that p110 contains an ATP-binding site and confers catalytic activity to the complex. The purified complex is known to be highly phosphorylated on both p85α and p110 subunits, and dephosphorylation generates a deactivated complex, indicating that phosphorylation is an important covalent modification of the complex and may modulate PtdIns 3-kinase activity.