AHNAK is a 5,890 amino acid protein encoded by the human gene AHNAK. The intronless AHNAK gene is located on human chromosome 11q12 and has three main structural regions: the 251 amino acid N-terminus, a large central region of 4390 amino acids with multiple repeated units of about 128 amino acids in length, and the 1002 amino acid C-terminus. The central region seems to have antiparallel beta-strands connected by intervening loops. Several putative regulatory elements are clustered within the C-terminal region, including nuclear export localization signals, a leucine zipper, and potential phosphorylation sites for Akt1 and PKC. AHNAK is believed to be an important signalling molecule involved in a wide range of physiological activities and may be required for neuronal cell differentiation.. AHNAK also appears to influence b-adrenergic regulation of cardiac L-type Ca2+ channel function.