Endosulfine alpha (ENSA)

Endosulfine alpha (ENSA) is a highly conserved cAMP-regulated phosphoprotein that serves as an endogenous ligand for the sulfonylurea receptor (ABCC8/SUR1), a regulatory subunit of the ATP-sensitive potassium (KATP) channel in pancreatic beta cells. By modulating this channel, ENSA is crucial for insulin secretion and glucose homeostasis. ENSA is also phosphorylated by Greatwall kinase, transforming it into a potent inhibitor of the PP2A-B55 phosphatase—essential for proper mitotic cell cycle progression. Beyond its metabolic roles, ENSA interacts with membrane-bound alpha-synuclein to inhibit its pathological aggregation, suggesting neuroprotective functions relevant to Parkinson's disease and related synucleinopathies. ENSA is expressed in brain, muscle, endocrine tissues, and oocytes, and different transcript variants have been observed across tissues. Its dysfunction is implicated in type 2 diabetes, some neurodegenerative and cancer processes, and it has critical roles in oocyte maturation and fertility[1][3][4][5][6][7].

Other names

Alpha-endosulfineARPP-19e1700020C18Rik (murine synonym)2610007F17Rik (murine synonym)

Modulation of KATP channel activity by binding sulfonylurea receptor (ABCC8/SUR1), inhibiting potassium efflux, stimulating insulin release.\nInhibition of protein phosphatase 2A-B55 to control mitotic progression.\nInhibition of membrane-induced alpha-synuclein aggregation, acting as a chaperone-like protein.