Identification of protein kinase B (PKB) as a phosphatidylinositol 3,4,5-trisphosphate binding protein in Dictyostelium discoideum.
We have searched for phosphatidylinositol (PI)-3,4,5-trisphosphate (PIP3) binding proteins in Dictyostelium discoideum using beads bearing a PIP3 analogue, PIP3-APB. One of the binding proteins with a molecular mass of 55 kDa was purified and its amino acid sequence was partially analyzed. Database searches showed that the analyzed sequence was identical to that of protein kinase B (PKB) of D. discoideum. The specific activity of D. discoideum PKB, when expressed together with constitutively active PI-3 kinase in mammalian cells, was elevated by about three-fold, suggesting that PKB could also act downstream of PI-3 kinase in Dictyostelium cells.
Tanaka
K
K
Laboratory of Biological Chemistry, Graduate School of Agriculture and Life Science, University of Tokyo, Japan.
Adachi
H
H
Konishi
H
H
Iwamatsu
A
A
Ohkawa
K
K
Shirai
T
T
Nagata
S
S
Kikkawa
U
U
Fukui
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D019556:COS Cells; D002352:Carrier Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002522:Chlorocebus aethiops; D017931:DNA Primers / Q000737:chemistry; D016054:DNA, Protozoan / Q000737:chemistry; D004023:Dictyostelium / Q000737:chemistry / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D008863:Microspheres; D008969:Molecular Sequence Data; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism* / Q000502:physiology*; D010716:Phosphatidylinositols / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000302:isolation & purification* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D017421:Sequence Analysis
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D017931:DNA Primers; D016054:DNA, Protozoan; D019869:Phosphatidylinositol 3-Kinases; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; C112403:PIP3-APB; C060974:phosphatidylinositol 3,4,5-triphosphate