BLNK required for coupling Syk to PLC gamma 2 and Rac1-JNK in B cells

Immunity. 1999 Jan;10(1):117-25. doi: 10.1016/s1074-7613(00)80012-6.

Abstract

Signaling through the B cell receptor (BCR) is essential for B cell function and development. Despite the key role of Syk in BCR signaling, little is known about the mechanism by which Syk transmits downstream effectors. BLNK (B cell LiNKer protein), a substrate for Syk, is now shown to be essential in activating phospholipase C (PLC)gamma 2 and JNK. The BCR-induced PLC gamma 2 activation, but not the JNK activation, was restored by introduction of PLC gamma 2 membrane-associated form into BLNK-deficient B cells. As JNK activation requires both Rac1 and PLC gamma 2, our results suggest that BLNK regulates the Rac1-JNK pathway, in addition to modulating PLC gamma 2 localization.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Amino Acid Sequence
  • Animals
  • B-Lymphocytes / enzymology*
  • B-Lymphocytes / metabolism
  • Calcium Signaling
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Carrier Proteins / physiology*
  • Cell Membrane / enzymology
  • Chickens
  • Enzyme Activation
  • Enzyme Precursors / metabolism*
  • GTP-Binding Proteins / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Isoenzymes / biosynthesis
  • Isoenzymes / genetics
  • Isoenzymes / metabolism*
  • JNK Mitogen-Activated Protein Kinases
  • Mice
  • Mitogen-Activated Protein Kinases*
  • Molecular Sequence Data
  • Phospholipase C gamma
  • Phosphoproteins*
  • Phosphorylation
  • Protein-Tyrosine Kinases / metabolism*
  • Receptors, Antigen, B-Cell / metabolism
  • Receptors, Antigen, B-Cell / physiology
  • Recombinant Fusion Proteins / biosynthesis
  • Syk Kinase
  • Type C Phospholipases / biosynthesis
  • Type C Phospholipases / genetics
  • Type C Phospholipases / metabolism*
  • Tyrosine / metabolism
  • rac GTP-Binding Proteins
  • ras Proteins / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • B cell linker protein
  • Carrier Proteins
  • Enzyme Precursors
  • Intracellular Signaling Peptides and Proteins
  • Isoenzymes
  • Phosphoproteins
  • Receptors, Antigen, B-Cell
  • Recombinant Fusion Proteins
  • Tyrosine
  • Protein-Tyrosine Kinases
  • SYK protein, human
  • Syk Kinase
  • Syk protein, mouse
  • Calcium-Calmodulin-Dependent Protein Kinases
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinases
  • Type C Phospholipases
  • Phospholipase C gamma
  • GTP-Binding Proteins
  • rac GTP-Binding Proteins
  • ras Proteins

Associated data

  • GENBANK/AF089727