BLNK Required for Coupling Syk to PLCγ2 and Rac1-JNK in B Cells

AbstractSignaling 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)γ2 and JNK. The BCR-induced PLCγ2 activation, but not the JNK activation, was restored by introduction of PLCγ2 membrane-associated form into BLNK-deficient B cells. As JNK activation requires both Rac1 and PLCγ2, our results suggest that BLNK regulates the Rac1-JNK pathway, in addition to modulating PLCγ2 localization