Table 2.

LPA receptors: molecular characteristics

Receptor	Number of residues	Molecular weight (kDa)	Chromosomal localization of genes in humans	Number of exons	Similarity to other receptors (in %)	Role of various residues in function (interaction with LPA)
LPAR1 or Edg2	364 Amino acids	∼41	9q31.3	Five exons
LPAR2 or Edg4	348 Amino acids	∼39	19p12	Five exons	∼50% identical at the amino acid level to LPAR1.
LPAR3 or Egd7	353 Amino acids	∼40	1p22.3–p31.1	Five exons	∼50% identical in amino acid sequence to LPAR1 and LPAR2 (mice)	Preference for 2-acyl-LPA rather than 1-acyl-LPA
LPAR4 or P2Y9 or GPR23	370 Amino acids	∼42	Xq21.1	Five exons	Less than 20% amino acid sequence identity with LPAR1, LPAR2 and LPAR3
LPAR5 or GPR92/93	372 Amino acids	∼41	12p13.31	Three exons	∼35% homology with LPAR4
LPAR6- P2Y5	344 Amino acids	∼39	13q14	Ten exons		Preference for 2-acyl-LPA rather than 1-acyl-LPA
GPR87	358 Amino acids	∼41	3q25.1	Three exons	Share 27% and 25% similarity with LPAR4 and LPAR5, respectively
P2Y10	364 Amino acids	∼39	Xq21.1	Five exons
TRPV1	839 Amino acids	~100.7	17p13.2	Nineteen exons		Activated only by LPA (18:1)