Functions coreceptor to limit the innate immune responses to viral infections; signaling occurs via FCER1G (, ). Down-regulates the production of IFNA1, IFNA2, IFNA4, IFNB1 and TNF by plasmacytoid dendritic cells that have been exposed to influenza virus or cytidine-phosphate-guanosine (CpG) dinucleotides, indicating it functions as a negative regulator of TLR7 and TLR9 signaling cascades ( ). Down-regulates interferon production in response to interaction with BST2 on HIV-1 infected cells . Activates a signaling cascade in complex with FCER1G that results in phosphorylation of Src family and Syk kinases and thereby triggers mobilization of intracellular Ca(2+) (, ). Does not interfere with the differentiation of plasmacytoid dendritic cells into antigen-presenting cells .
Subcellular locations: Cell membrane
Detected on plasmacytoid dendritic cells (at protein level). Detected on plasmacytoid dendritic cells, but not on monocytes or B cells.