Neuropeptides and derived fragments

Compound

Galanin (human 1-30)

Galanin is a thirty-residue human neuropeptide acting through the galanin receptor family, and the reference ligand against which spexin's receptor selectivity is measured.

GAL · Galanin(1-30)

Compound

Gonadorelin (GnRH-I)

Gonadorelin is the ten-residue hypothalamic releasing hormone GnRH-I, carrying an N-terminal pyroglutamate and a C-terminal amide.

GnRH-I · Gonadotropin-releasing hormone · LHRH · LH-RH

Compound

Spadin

Spadin is a sortilin-propeptide-derived peptide reported to interact with sortilin and to inhibit the TREK-1 potassium channel, and the parent design from which PE 22-28 was derived.

Compound

Spexin

Spexin is an endogenous fourteen-residue amidated neuropeptide identified by computational screening of the human proteome, and a ligand of galanin receptors 2 and 3.

SPX · Spexin-1 · NPQ

receptor

Galanin receptors

The galanin receptor family comprises three G protein-coupled receptors. GALR1 and GALR3 signal through Gi/o, while GALR2 signals mainly through Gq/11. Spexin activates GALR2 and GALR3 but not GALR1 in the reported ligand panel. Structural studies compared galanin-bound GALR1-Go and GALR2-Gq with spexin-bound GALR2-Gq, providing evidence for ligand recognition and subtype-dependent coupling.