The Stomatin-like protein family contains five members and are characterized by the presence of a structurally conserved core called the stomatin-domain. This stomatin-domain is further related to a domain found in members of the prohibitin, flotillin and HflK/HflC protein families and has accordingly also been called the SPFH domain.

All mammalian stomatin proteins are integral membrane protein with a single, relatively short, hydrophobic membrane insertion domain, followed by the core stomatin-domain. A single conserved proline residue (known to be a potent helix breaker) in the hydrophobic region is required for the formation of the protein’s hairpin structure. The N-terminal domain is extracellular. Stomatin-like protein 1 (STOML1) has a typical stomatin-domain at the N-terminus and an additional sterol carrier protein-2 (SCP-2) domain at the C-terminus. STOML-1 is targeted to the late endosomal compartment where it interacts with stomatin. STOML-1 is predominantly expressed in the brain, in a subpopulation of sensory neurons in the dorsal root ganglia. Much lower levels are detected in other tissues¹.

Following anoxia, STOML-1 expression is up-regulated by the oxidative response factor SKN-1/Nrf. SKN-1/Nrf is required for both rapid mitochondrial refusion and rapid behavioral recovery during reoxygenation suggesting that STOML-1 helps facilitate mitochondrial dynamics following anoxia².

STOML-1 also modulates the proton-sensitive members of the acid-sensing ion channel (ASIC) family. STOML-1 strongly inhibits ASIC1a and accelerates the inactivation time constant of ASIC3, but has no effect on the splice variant ASIC1b³.