TIMD4
Domain
Recognizes phosphatidyl serine via its immunoglobulin domain.
Function
Phosphatidylserine receptor that plays different role in immune response including phagocytosis of apoptotic cells and T-cell regulation. Controls T-cell activation in a bimodal fashion, decreasing the activation of naive T-cells by inducing cell cycle arrest, while increasing proliferation of activated T-cells by activating AKT1 and ERK1/2 phosphorylations and subsequent signaling pathways (By similarity). Also plays a role in efferocytosis which is the process by which apoptotic cells are removed by phagocytic cells (PubMed:32703939, PubMed:34067457). Mechanistically, promotes the engulfment of apoptotic cells or exogenous particles by securing them to phagocytes through direct binding to phosphatidylserine present on apoptotic cells, while other engulfment receptors such as MERTK efficiently recognize apoptotic cells and mediate their ingestion (PubMed:32640697). Additionally, promotes autophagy process by suppressing NLRP3 inflammasome activity via activation of LKB1/PRKAA1 pathway in a phosphatidylserine-dependent mechanism (By similarity).
(Microbial infection) Plays a positive role in exosome-mediated trafficking of HIV-1 virus and its entry into immune cells.
Sequence Similarities
Belongs to the immunoglobulin superfamily. TIM family.
Cellular localization
- Cell membrane
- Single-pass type I membrane protein
- Secreted
- Extracellular exosome
Alternative names
TIM4, TIMD4, T-cell immunoglobulin and mucin domain-containing protein 4, TIMD-4, T-cell immunoglobulin mucin receptor 4, T-cell membrane protein 4, TIM-4