Cross-linking of the B cell receptor induces activation of phospholipase D through Syk, Btk and phospholipase C-gamma2.
Phospholipase D (PLD) has been proposed to play a key role in the signal transduction of cellular responses to various extracellular signals. Herein we provide biochemical and genetic evidence that cross-linking of the B cell receptor (BCR) induces rapid activation of PLD through a Syk-, Btk- and phospholipase C (PLC)-gamma2-dependent pathway in DT40 cells. Activation of PLD upon BCR engagement is completely blocked in Syk- or Btk-deficient cells, but unaffected in Lyn-deficient cells. Furthermore, in PLC-gamma2-deficient cells, BCR engagement failed to activate PLD. These results demonstrate that Syk, Btk and PLC-gamma2 are essential for BCR-induced PLD activation.
Hitomi
T
T
Department of Biochemistry, Kobe University School of Medicine, Japan.
Yanagi
S
S
Inatome
R
R
Yamamura
H
H
D000077329:Agammaglobulinaemia Tyrosine Kinase; D000818:Animals; D002460:Cell Line; D003432:Cross-Linking Reagents; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000378:metabolism*; D051966:Phospholipase C gamma; D010739:Phospholipase D / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D000072377:Syk Kinase; D010738:Type C Phospholipases / Q000378:metabolism*
D003432:Cross-Linking Reagents; D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D011947:Receptors, Antigen, B-Cell; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; D000072377:Syk Kinase; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D010739:Phospholipase D