Two methionines in the N-terminus can serve as initiation sites, at position 1 and position 64, resulting in two forms of Orai1. Potential sequences in the longer version include a caveolin binding site (Yu et al., 2010), an adenylyl cyclase 8 binding site (Willoughby et al., 2012), a potential phosphatidylinositol 4,5-bisphosphate binding site, two potential protein kinase C phosphorylation sites (Kawasaki et al., 2010), and a recognition site for the membrane skeletal protein 4.1 (GASCARD et al., 1993).