Role of IκB kinase ß in regulating the remodeling of the CARMA1-Bcl10-MALT1 complex.

ABSTRACT

The current work investigates the notion that inducible clustering of signaling mediators of the IKK pathway is important for platelet activation. Thus, while the CARMA1, Bcl10, and MALT1 (CBM) complex is essential for triggering IKK/NF-κB activation upon platelet stimulation, the signals that elicit its formation and downstream effector activation remain elusive. We demonstrate herein that IKKß is involved in membrane fusion, and serves as a critical protein kinase required for initial formation and the regulation of the CARMA1/MALT1/Bcl10/CBM complex in platelets. We also show that IKKß regulates these processes via modulation of phosphorylation of Bcl10 and IKKγ polyubiquitination. Collectively, our data demonstrate that IKKß regulates membrane fusion and the remodeling of the CBM complex formation.