Neurites are key morphological features of neurons, and are classified into axons and dendrites. Leucine-rich repeat (LRR) domains are often found in neurite development-controlling proteins. Slitrk proteins are leucine-rich repeat containing transmembrane proteins, parts of which are similar to Slit and neurotrophin receptor.

All six members of the Slitrk family, including Slitrk1, contain putative hydrophobic signal sequences and membrane-spanning regions. Slitrk1 is strongly expressed in the subventricular zone of the cerebral cortex, the pyramidal cell layer of the hippocampus and in the thalamus and hypothalamus¹.

Slitrk1, can regulate synapse formation between hippocampal neurons. Slitrk1 is enriched in postsynaptic fractions and is localized to excitatory synapses. Overexpression of Slitrk1 in hippocampal neurons increases the number of synaptic contacts on these neurons. Furthermore, decreased expression of Slitrk1 in hippocampal neurons leads to a reduction in the number of excitatory, but not inhibitory, synapses formed in hippocampal neuron cultures. In addition, different leucine rich repeat domains of the extracellular region of Slitrk1 are necessary to mediate interactions with Slitrk binding partners of the LAR receptor protein tyrosine phosphatase family, and to promote dimerization of Slitrk1. In addition, Slitrk1 binds with PSD-95 through its intracellular tail. Thus, through PSD-95, Slitrk1 regulates signaling of NMDA and AMPA receptors².