Leucine-rich repeat and fibronectin type-III domain-containing protein 5 (LRFN5)

Leucine-rich repeat and fibronectin type-III domain-containing protein 5 (LRFN5), also referred to as SALM5, is a type I transmembrane protein predominantly expressed in the central nervous system.[1][2][3] It is part of a family of five synaptic adhesion molecules that feature extracellular leucine-rich repeat and fibronectin type III domains.[2] LRFN5 plays an essential role in synaptic development, organization, and plasticity, mediating cell-cell interactions required for the formation and differentiation of synapses, including both excitatory and inhibitory presynaptic sites.[1][2][3] It acts as a dimer and interacts with the LAR family of receptor tyrosine phosphatases, inducing presynaptic differentiation.[1] Changes in LRFN5 locus structure and expression are associated with neurodevelopmental and neuropsychiatric disorders, such as autism spectrum disorder and major depressive disorder; in particular, LRFN5 serum levels have demonstrated strong diagnostic utility as a biomarker for major depressive disorder.[2] LRFN5 is also implicated in neuroinflammatory processes and immune modulation through its interactions with the herpes virus entry mediator.[2] The gene is located in a large topologically associating domain, suggesting complex, cell-specific regulation at both structural and translational levels.[1]

Other names

SALM5FIGLER8C14orf146fibronectin type III, immunoglobulin and leucine rich repeat domains 8