May be involved in promoting the maturation of dendritic spines, probably via regulating SIPA1L1 levels at the postsynaptic density of synapses. Interacts (via C-terminus) with SHANK3 (via PDZ domain). Interacts (via coiled coil) with SIPA1L1. Can form homooligomers. Rather found at excitatory than inhibitory synapses. Belongs to the LZTS3 family. Extended N-terminus.