ATPase, Ca++ Transporting, Type 2C, Member 1 (ATP2C1)

ATP2C1 encodes one of the SPCA proteins, a Ca²⁺ ion-transporting P-type ATPase. This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the transport of the calcium. Defects in this gene cause Hailey-Hailey disease, an autosomal dominant disorder.

ATP2C1a was predicted to encode 919 amino acids, and ATP2C1b was predicted to encode 888 amino acids. The protein encoded by ATP2C1 was highly homologous to rat Pmr1, which in turn is homologous to the yeast calcium pump Pmr1, but less homologous to other calcium pumps. ATP2C1 is highly expressed in human epidermal keratinocytes and at various levels in other human tissues. Patients with HHD are not known to have extracutaneous manifestations of the disease.