Receptor protein tyrosine phosphatases PTPRO and PTPRS (PTPsigma) are co-expressed with NTRK3 (TRKC) in a large portion of NTRK3 positive neurons. Recombinant PTPRO (Beltran et al. 2003, Hower et al. 2009, Tchetchelnitski et al. 2014) and PTPRS (Faux et al. 2007, Tchetchelnitski et al. 2014) are both able to bind NTRK3 and promote NTRK3 dephosphorylation, thus attenuating NTRK3 signaling. The precise mechanism has not been elucidated.
In addition to interaction between PTPRS and NTRK3 in-cis, extracellular domain of pre-synaptic PTPRS can bind in-trans to extracellular domain of post-synaptic NTRK3, contributing to synapse formation (Takahashi et al. 2011, Coles et al. 2014).