Protein-tyrosine phosphatase receptor type Z (PTPRZ) is predominantly expressed in the
developing brain as a CS proteoglycan. PTPRZ has long (PTPRZ-A) and short type (PTPRZ-
B) receptor forms by alternative splicing. The extracellular CS moiety of PTPRZ is required
for high-affinity binding to inhibitory ligands, such as pleiotrophin (PTN), midkine, and
interleukin-34; however, its functional significance in regulating PTPRZ activity remains
obscure. We herein found that protein expression of CS-modified PTPRZ-A began earlier …