Table 2

Human cloned leukotriene receptors^2-a

IUPHAR name	BLT₁	BLT₂	CysLT₁	CysLT₂	ALX
IUPHAR code	2.1 :BLT :1 :BLT1	2.1 :BLT :2 :BLT2	2.1 :CLT :1 :CLT1	2.1 :CLT :2 :CLT2	2. :ALX
Alternate names	Leukotriene B₄	Leukotriene B₄	Leukotriene D₄/E₄ ^2-b	Leukotriene C₄ ^2-b	Lipoxin A₄/FPRL-1
Amino acid composition	352 (h)	358 (h)	337 (h)	346 (h)	351
Selective ligand	None	None	None	None	None
Non-selective ligand	LTB₄	LTB₄	LTC₄/LTD₄/LTE₄	LTC₄/LTD₄/LTE₄	LXA₄/fMLP
Gene/chromosome	14q11.2-q12	14q11.2-q12	Xq13-q21	13q14.2	19q13.3
Primary coupling^2-c	G₁₆, G_i2	G_q-like, G_i-like, G_z-like	G_αq	G_αq	G_i, G_q
Primary expression	Leukocytes, thymus, spleen	Ovary, liver, leukocytes, ubiquitous	Smooth muscle (lung, intestine), spleen, peripheral blood leukocytes	Heart, spleen, peripheral blood leukocytes, adrenal medulla, brain	Lung, peripheral blood leukocytes, spleen
Accession number (Swiss-Prot)	Q15722(h)	Q9NPC1 (h)	Q9Y271 (h)	Q9NS75 (h)	P25090 (h)

Data are from the following references: Fiore et al., 1992, 1994; Perez et al., 1992; Maddox et al., 1997; Takano et al., 1997; Yokomizo et al., 1997;Lynch et al., 1999; Sarau et al., 1999;Heise et al., 2000; Nothacker et al., 2000; Takasaki et al., 2000; Figueroa et al., 2001.

↵2-a The reader is referred to the text for the mouse cloned receptors.
↵2-b No longer acceptable since all ligands activate the same receptor in isolated human bronchi.
↵2-c These observations should be considered with some reserve since there is marked variation between the types of G-proteins present in cells (see text). (h) indicates human.