TUCAN/CARDINAL and DRAL participate in a common pathway for modulation of NF-kappaB activation.

Proteins containing the caspase recruiting domain (CARD) have emerged as critical regulators of different signal transduction pathways, including those controlling apoptosis and activation of necrosis factor (NF)-kappaB transcription factor. TUCAN/CARDINAL is a recently identified CARD-containing protein involved in regulation of caspases and NF-kappaB activation. We find that TUCAN/CARDINAL associates with DRAL, a p53-responsive gene implicated in induction of apoptosis. We also show that, whereas TUCAN/CARDINAL exerts a suppressive effect on NF-kappaB activity, expression of DRAL results in enhancement of NF-kappaB activation. Thus, our observations suggest that DRAL and TUCAN/CARDINAL may participate in a regulatory mechanism that coordinates cellular responses controlled by NF-kappaB transcription factor.