Photocrosslinking-induced CRAC channel-like Orai1 activation independent of STIM1.

ABSTRACT: Ca²⁺ release-activated Ca²⁺ (CRAC) channels, indispensable for the immune system and various other human body functions, consist of two transmembrane (TM) proteins, the Ca²⁺-sensor STIM1 in the ER membrane and the Ca²⁺ ion channel Orai1 in the plasma membrane. Here we employ genetic code expansion in mammalian cell lines to incorporate the photocrosslinking unnatural amino acids (UAA), p-benzoyl-L-phenylalanine (Bpa) and p-azido-L-phenylalanine (Azi), into the Orai1 TM domains at different sites. Characterization of the respective UAA-containing Orai1 mutants using Ca²⁺ imaging and electrophysiology reveal that exposure to UV light triggers a range of effects depending on the UAA and its site of incorporation. In particular, photoactiv

SUBMITTER: Maltan L 

PROVIDER: S-EPMC9995687 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature