The leucine-rich repeat (LRR) superfamily is a diverse protein family that consist of leucine-rich domains (LRR domains). The LRR domain is known to regulate protein-protein interaction or cell adhesion. A Large portion of LRR proteins mediate the differentiation and development of nervous tissues¹.

The fibronectin leucine-rich transmembrane 3 (FLRT3) protein play an important function during excitatory neuron development including neuron migration, axon guidance, or synapse formation². FLRT3 gene is encoding single pass transmembrane domain with one extracellular LRR domain and a juxtamembrane fibronectin type 3 (FNIII) module. It was found to be expressed in kidney, brain, pancreases, skeletal muscle, lungs, liver placenta and heart³.

FLRT3 display a unique multifunctional property acting as chemorepellent by binding to the Netrin receptor Unc5D and regulating radial migration of subventricular progenitors. In addition, it acts as homophilic adhesion molecule regulating the tangential dispersion of migrating neuron progenitors in the developing cortex⁴. FLRT3 knock out in mice leads to a variety of malformations, like disorganized basement membrane, failure of embryonic turning and ventral body closure, cardiac bifida and asymmetric development of headfolds⁵.