Recombinant Human LAMP Fc Chimera Protein, CF

LAMP (limbic system-associated membrane protein) is a member of the IgLON (immunoglobulin LAMP, OBCAM and neurotrimin) subfamily within the Ig superfamily. All IgLON family members are glycosylphosphatidylinositol (GPI)-anchored neural cell adhesion molecules that are involved in cell-cell recognition and may have a role in mediating selective neuronal growth and axon targeting. LAMP cDNA encodes a 338 amino acid (aa) residues precursor protein containing a 28 aa N-terminal signal peptide, a 23 aa C-terminal propeptide and a 287 aa mature chain with 3 Ig-like C2-type domains and a GPI-anchor attachment site. In the developing brain, LAMP exhibits a specific pattern of expression in the cortical and subcortical limbic areas, which are important in cognition, emotion, memory, and learning. LAMP is also expressed in single layers of the superior colliculus, spinal chord and cerebellum. LAMP promotes adhesion and growth of limbic axons primarily via homophilic interaction and in part by modulating calcium influx through L-type calcium channels in limbic neurons. Heterophilic interactions between LAMP and neurotrimin have also been demonstrated. LAMP has been shown to inhibit the outgrowth of neurotrimin-expressing dorsal root ganglion neurons in a heterophilic manner. Antibody perturbation studies showed that LAMP is necessary for normal circuit formation in the limbic system, including the septo-hippocampal connection and hippocampal mossy fibers. LAMP acts as an attractive guidance signal for the limbic thalamic axons and can induce branch formation, but also acts as a repulsive axon guidance signal for nonlimbic thalamic axons (1 - 5).