Burman et al Supplementary Table 1

Conserved motifs between vertebrate aminergic receptors and Amphioxus putative aminergic GPCRs

Location / Motif/residue conserved in aminergic receptors / Description / Amphi
D1/beta / Amphi
Am1 / Amphi
Am2 / Amphi
Am3 / Amphi
Am4 / Amphi
Am5 / Amphi
Am6 / Amphi
Am7 / Amphi
Am8 / Amphi
Am9 / Amphi
Am10 / Amphi
Am11
N-terminus / Asn-X-Ser/Thr / N-linked glycosylation site-binding site for carbohydrates on the external portion of receptor / 2 / 1 / 1 / 5 / 1 / 2 / 3 / 0 / 2 / 6 / 2 / 1
TM I / Gly–Asn (N1.50) -X-Leu-Val-Ileu/Cys / Typical Class I GPCR motif – highly conserved in known GPCRs / GNVLVI / GNLMVL / GNLLVI / GNLLVI / GNVLVF / GNLLVC / GNLAVI / GNLLAI / GNVMVV / GNILVC / GNVLVC / GNVLVC
TM II / Asp (D2.50)- Val / Involved in agonist binding and G-protein coupling/ activation / DL / DL / DL / DF / DL / DL / DV / DL / DL / DI / DL / DL
EC I / Cys / Disulphide bonds with Cys in EC II- stabilises
Receptor / C / C / C / C / C / C / C / C / C / C / C / C
EC I / Trp / Highly conserved in known aminergic GPCRs / W / W / W / W / W / W / W / W / W / W / W / W
TM III / Asp (D3.32) / Important in binding of biogenic amines since contacts protonated amine of all aminergic ligands – mutation studies show function is only kept with substitution with Glu / D / D / D / D / D / D / D / D / D / D / D / D
Thr (T3.37) / Part of “binding core” / T / T / T / S / T / T / T / S / Q / T / T / T
Ser (S3.39) / Highly conserved in known aminergic GPCRs / S / S / S / S / S / S / S / S / S / S / S / S
TM III/ICII / Asp-Arg (R3.50)-Tyr / The DRY motif is conserved in Class 1 GPCRs It is involved in the activation of G-proteins / DRF / DRY / DRY / DRY / DRY / DRY / DRY / DRY / DRY / ERH / DRY / DRY
TM IV / Trp (W4.50)-X-Ser / Involved in agonist binding in β2-adrenergic receptors / WGI / WCL / WLC / WII / WII / WVL / WIS / WIL / WVV / YIA / WIV / WVL
Pro (P4.59) / Highly conserved in Class I GPCRs / L / I / P / P / P / P / P / P / P / P / L / P
EC II / Cys / Forms disulfide bond with Cys in EC I – stabilises receptor structure / C / C / C / C / C / C / C / C / C / C / C / C
Asn-X-Ser/Thr / N-linked glycosylation site – binding site for carbohydrates on the external portion of the receptor / NLS / No / No / No / No / No / No / No / No / No / NNT / No
TM V / Ser - Ser (S5.43)-X-X-Ser (S5.46) / Shown to interact with hydroxyl groups on catecholamine ring in adrenergic receptors / SSLIS / SSFVS / SSCVS / ASLVE / SVSAS / STMGS / SVALS / MSFTE / SAMLS / SITMS / VAFGT / STIGS
Phe (F5.47)-X-X-Pro / Highly conserved in aminergic receptors / FYIP / FYIP / FYAP / FFTP / FYIP / FYIP / FWVP / FVVP / YHLP / FYIP / YYIP / FYIP
TM VI / Cys-Trp-Leu
-Pro (P6.50) -Phe-Phe / Signature motif of aminergic GPCRs- involved in both receptor binding and G-protein activation / CWLPFF / CWLPFF / CWLPFF / CWAPYT / CWFPFF / CWVPFF / CWLPFF / CWCPYM / CWIPFI / CWYPFF / CWTPYF / CWLPFF
Asn (N6.55) / Interacts with β-hydroxyl group of catecholamines / N / N / N / T / Y / Y / Y / T / Y / Y / F / Y
TM VII / Trp (W7.40) -X-Gly / Highly conserved residues in aminergic GPCRs / WLG / WLG / WLG / WFL / WLG / WLG / WLG / WLL / WMA / WVG / WLG / WLG
Asn (N7.45)- Ser / Involved in binding of both agonist and antagonists in β-adrenergic receptors – interactions between the residues caused by agonist binding leads to activation of G-proteins / NS / NS / NS / NS / NS / NS / NS / NS / NS / NS / NS / NS
Asn-Pro (P7.50) -X
-X-Tyr / Highly conserved in aminergic GPCRs – involved in G-protein activation and with binding of GTP binding proteins ARF and Rho / NPIIY / NPIIY / NPIIY / NPIVY / NPVIY / NPAIY / NPIIY / NPFLY / NPIVY / NPIIY / NPCVY / NPLIY
C-terminal / Cys / Palmitoylation site –anchors the C-terminus to the cell membrane, effectively making a fourth intracellular loop / 3 / 3 / 3 / 1 / 1 / 1 / No / 2 / No / 1 / 3 / 3

Key residues and motifs involved in aminergic receptor ligand binding and ligand activation of the receptors. X = any residue. Information taken from Bockaert and Pin, 1999; Shi and Javitch, 2002; and Xhaard et al., 2006.