Nature Communications (May 19): CRAB Engineered Peptide Inhibitors Block STIM1-ORAI Coupling in CRAC Channels, Enable Programmable Immune Control
A Nature Communications paper from a Texas A&M Health team published May 19 reported the engineering of genetically encoded calcium release-activated calcium channel (CRAC) inhibitory binders called CRABs — peptide inhibitors derived from the ORAI C-terminal tail that selectively interfere with STIM1-ORAI coupling. The plasma-membrane-anchored CRAB variant potently inhibits calcium influx and downstream NFAT signaling. The platform spans optogenetic (Opto-CRAB) and chemogenetic (Chemo-CRAB) variants for graded, real-time control of CRAC activity. In a zebrafish Stormorken syndrome model, CRABs rescued thrombocyte progenitor production. The therapeutic implication: a peptide-based adjustable brake on T-cell calcium signaling that could enable safer, more controllable immune cell therapies — CAR-T cytokine release moderation, autoimmune T-cell quenching, transplantation tolerance induction.