Caspase recruitment domain (CARD)-dependent cytoplasmic filaments mediate bcl10-induced NF-kappaB activation.

Mucosa-associated lymphoid tissue (MALT) lymphomas are associated with overexpression and constitutive activity of bcl10, a caspase recruitment domain (CARD)-containing protein that activates NF-kappaB. Here, we show that arrangement of overexpressed bcl10 protein in cytoplasmic filaments is essential for recruitment of signal transducer molecules-involved NF-kappaB activation. We also show that cytoskeleton elements regulate bcl10 signaling.Thus, organized assemblage of proteins in ordered structures linked to the cytoskeleton network may represent a general mechanism for intracellular signaling.