Table 2.

PtdSer recognition sites related to immune or blood coagulation

PtdSer binding recognition site	Immune receptor or coagulation factor	Ca2+ dependence	Function after binding to PtdSer	References
GLA domain	GAS6/PROS1 ligand of immune receptor TAM	Yes	Identify apoptotic cells (GAS6/PROS1), stable thrombosis and maintain platelet stability (GAS6)	[33, 34]
	Coagulation factor vitamin K-dependent proteins (Factor VIIa, IXa, Xa, prothrombin and activated protein C)	Yes	Coagulation and anticoagulation	[107, 189]
Discoidin-like C2 domain	MFG-E8 ligand of immune receptor αvβ3 or αvβ5 integrins	No	Identify apoptotic cells	[63, 64, 154, 155]
	Coagulation factor Factor Va and Factor VIIIa	No	Maintain protein stability	[191]
IgV-like domain	Immune receptor TIM family (TIM-1, TIM-3, TIM-4)	Yes	Identify apoptotic cells and promote endocytosis.	[35]
	Immune receptor CD300a	Yes	Identify apoptotic cells	[35]
	Immune receptor RAGE	Not sure yet	Identify apoptotic cells	[69, 168]
TSP-1	Immune receptor BAI1	Not sure yet	Promote maximum phagocytosis of apoptotic cells	[66]
EGF-like domain	Immune receptor stabilin-1 and stabilin-2	Yes	Endocytosis and cell fusion	[67, 68, 164–166]