Maschalidi S Nunes-Hasler P Nascimento CR Sallent I Lannoy V Garfa-Traore M Cagnard N Sepulveda FE Vargas P Lennon-Duménil AM van Endert P Capiod T Demaurex N Darrasse-Jèze G Manoury B 2017 Dendritic cells (DC) have the unique ability to present exogenous antigens via the major histocompatibility complex class I pathway to stimulate naive CD8+ T cells. In DCs with a non-functional mutation in Unc93b1 (3d mutation), endosomal acidification, phagosomal maturation, antigen degradation, antigen export to the cytosol and the function of the store-operated-Ca2+-entry regulator STIM1 are impaired. These defects result in compromised antigen cross-presentation and anti-tumor responses in 3d-mutated mice. Here, we show that UNC93B1 interacts with the calcium sensor STIM1 in the endoplasmic reticulum, a critical step for STIM1 oligomerization and activation. Expression of a constitutively active STIM1 mutant, which no longer binds UNC93B1, restores antigen degradation and cross-presentation in 3d-mutated DCs. Furthermore, ablation of STIM1 in mouse and human cells leads to a decrease in cross-presentation. Our data indicate that the UNC93B1 and STIM1 cooperation is important for calcium flux and antigen cross-presentation in DCs. application/pdf https://sonar.ch/global/documents/232615 eng info:eu-repo/semantics/altIdentifier/doi/10.1038/s41467-017-01601-5 info:eu-repo/semantics/altIdentifier/pmid/29158474 info:eu-repo/semantics/openAccess Nature communications. - 2017 Animals Antigen Presentation Antigens Calcium Cells, Cultured Cross-Priming Dendritic Cells Endoplasmic Reticulum Female Humans Male Membrane Transport Proteins Mice Mice, Inbred C57BL Protein Binding Stromal Interaction Molecule 1 UNC93B1 interacts with the calcium sensor STIM1 for efficient antigen cross-presentation in dendritic cells. http://purl.org/coar/resource_type/c_6501