H, C and N backbone NMR chemical shift assignments of the C-terminal P4 domain of Ahnak.

Ahnak is a ~ 700 kDa polypeptide that was originally identified as a tumour-related nuclear phosphoprotein, but later recognized to play a variety of diverse physiological roles related to cell architecture and migration. A critical function of Ahnak is modulation of Ca signaling in cardiomyocytes by interacting with the β subunit of the L-type Ca channel (Ca1.2). Previous studies have identified the C-terminal region of Ahnak, designated as P3 and P4 domains, as a key mediator of its functional activity. We report here the nearly complete H, C and N backbone NMR chemical shift assignments of the 11 kDa C-terminal P4 domain of Ahnak. This study lays the foundations for future investigations of functional dynamics, structure determination and interaction site mapping of the Ca1.2-Ahnak complex.