LY9

LY9 belongs to the SLAM family of immunomodulatory receptors (see SLAMF1; MIM 603492) and interacts with the adaptor molecule SAP (SH2D1A; MIM 300490) (Graham et al., 2006 [PubMed 16365421]).

Lymphocyte antigen 9

Self-ligand receptor of the signaling lymphocytic activation molecule (SLAM) family. SLAM receptors triggered by homo- or heterotypic cell-cell interactions are modulating the activation and differentiation of a wide variety of immune cells and thus are involved in the regulation and interconnection of both innate and adaptive immune response. Activities are controlled by presence or absence of small cytoplasmic adapter proteins, SH2D1A/SAP and/or SH2D1B/EAT-2. May participate in adhesion reactions between T lymphocytes and accessory cells by homophilic interaction. Promotes T-cell differentiation into a helper T-cell Th17 phenotype leading to increased IL-17 secretion; the costimulatory activity requires SH2D1A (PubMed:22184727).
Promotes recruitment of RORC to the IL-17 promoter (PubMed:22989874).
May be involved in the maintenance of peripheral cell tolerance by serving as a negative regulator of the immune response. May disable autoantibody responses and inhibit IFN-gamma secretion by CD4(+) T-cells. May negatively regulate the size of thymic innate CD8(+) T-cells and the development of invariant natural killer T (iNKT) cells (By similarity).

Cell adhesionIEA:UniProtKB-KW
Innate immune responseIEA:UniProtKB-KW
Positive regulation of interleukin-17 productionManual Assertion Based On ExperimentIDA:UniProtKB
T cell activationManual Assertion Based On ExperimentIBA:GO_Central
T-helper 17 cell lineage commitmentManual Assertion Based On ExperimentIDA:UniProtKB

Membrane
Cell membrane

Extracellular: 48-454
Helical: 455-476
Cytoplasmic: 477-655