Recombinant Human Protocadherin-17 Protein, CF

Human Protocadherin 17 (PCDH17; also called Protocadherin‑68) is an approximately 1159 amino acid (aa) glycoprotein belonging to the delta2 subgroup of protocadherins, type I transmembrane proteins that exhibit calcium‑dependent but relatively weak homophilic adhesion (1‑3). Like other delta2 protocadherins, PCDH17 cDNA encodes a signal sequence (aa 1‑17), six cadherin domains of about 100 aa each (aa 18‑695), a transmembrane sequence and a cytoplasmic domain (1). It contains an extracellular RGD cell attachment motif that may mediate integrin adhesion (3). Typical of protocadherins, an alternately spliced 889 aa form of human PCDH17 diverges at aa 876 within the cytoplasmic domain and lacks two conserved cytoplasmic motifs (1, 2). Within the extracellular domain, human PCDH17 shares 98% aa sequence identity with mouse and bovine, 99% with rat and equine, and 97% with porcine PCDH17. PCDH17 is constitutively expressed in the central nervous system (3). It is one of several PCDH molecules that shows region specificity in the basal ganglia, forming gradients (3). Early in postnatal life, it is preferentially expressed in motor and auditory cortices and is correlated with thalamo‑cortical and intrahippocampal circuits (3‑5). Its expression is increased in the Broadman area of the brain in subjects with schizophrenia (3). PCDH17 is frequently silenced in squamous cell carcinomas such as those in the esophagus and larynx, especially if they are poorly differentiated (3, 6, 7). Ectopic PCDH10 expression reduces tumor cell proliferation and migration (6).