Syntaxin11 deficiency inhibits CRAC channel priming to suppress cytotoxicity and gene expression in T lymphocytes independent of membrane trafficking.

Syntaxin11 deficiency inhibits CRAC channel priming, reducing calcium entry and gene expression in T lymphocytes independently of membrane trafficking, with implications for immune disorders.

• Why it matters: Understanding how STX11 regulates calcium signaling in T cells addresses gaps in knowledge about familial hemophagocytic lymphohistiocytosis 4 (FHLH4), a fatal immune disorder with defective cytotoxicity.
• What they did: The study used patient T lymphocytes and cell lines to show that STX11 binds and regulates Orai1, affecting SOCE, CRAC currents, NFAT activation, interleukin-2 expression, and degranulation without altering membrane trafficking, and employed mutants and ionomycin to demonstrate rescue of calcium entry.
• The result: Findings suggest that STX11 primes Orai1 for multimeric assembly and gating, revealing a primary SNARE function in channel priming that may have preceded membrane trafficking roles, advancing understanding of T cell calcium regulation.