Persephin

Persephin (PSPN) is the smallest and most divergent member of the GDNF family of ligands. Like its relatives GDNF, neurturin and artemin, it is synthesized as a pre-pro-protein and secreted as a disulfide-bonded homodimer with the characteristic cystine-knot architecture; but persephin engages a distinct co-receptor, GFRα4, to activate the RET receptor tyrosine kinase. Expression profiling places persephin principally in the developing nervous system, kidney and thyroid, with persistent low-level expression in adult central neurons. Functionally, persephin supports the survival and differentiation of midbrain dopaminergic neurons and motor neurons with potency comparable to GDNF in vitro, yet exhibits a narrower in vivo spectrum: unlike GDNF, it does not sustain enteric or kidney development, indicating specialized rather than ubiquitous neurotrophic roles. Persephin also promotes survival of central noradrenergic neurons and, notably, contributes to thyroid C-cell (parafollicular cell) development and maintenance through RET signaling in the calcitonin-producing lineage, linking this ligand to both neuroprotective therapeutic exploration and endocrine biology.