GUCY2C: GUCY2C is a transmembrane receptor expressed in intestinal epithelial cells

• Gene Information: Guanylate cyclase 2C, also known as guanylyl cyclase C (GC-C), intestinal guanylate cyclase, guanylate cyclase-C receptor, or the heat-stable enterotoxin receptor (hSTAR) is an enzyme that in humans is encoded by the GUCY2C gene.
• Protein Expression: Guanylyl cyclase is an enzyme found in the luminal aspect of intestinal epithelium and dopamine neurons in the brain. The receptor has an extracellular ligand-binding domain, a single transmembrane region, a region with sequence similar to that of protein kinases, and a C-terminal guanylate cyclase domain
• Signaling Pathway: GUCY2C is activated upon binding of paracrine hormones (guanylin and uroguanylin) that lead to formation of cyclic GMP from GTP and activation of downstream signaling pathways that are associated with normal homeostasis.
• Therapeutic Inhibition: Humanized mice can be used to study the in vivo efficacy evaluation of GUCY2C antibody drug.

GUCY2C

•A chimeric CDS that encodes human GUCY2C signal peptide and extracellular domain, part of mouse Gucy2c transmembrane and cytoplasmic domain, followed by mouse 3’UTR-STOP is inserted right after mouse Gucy2c ATG to replace the exon 1 of mouse Gucy2c gene. 

• Human GUCY2C mRNA are specifically and correctly expressed in B-NDG hGUCY2C mice

Human GUCY2C were detectable in B-NDG hGUCY2C mice by RT-PCR and sequencing. Small intestine tissues were isolated from wild-type C57BL/6 mice (+/+) and homozygous B-NDG hGUCY2C mice (H/H). Primers were designed to detect the human and mouse GUCY2C.  Human GUCY2C mRNA was detectable in B-NDG hGUCY2C mice, but not in wild-type mice. Sequencing of the PCR products confirmed that the amplified sequences were consistent with database reference sequences.

• Human GUCY2C was detected in small intestine and colon of homozygous B-NDG hGUCY2C mice, but not in wild-type mice.

Immunohistochemical (IHC) analysis of GUCY2C protein expression in wild-type mice and B-NDG hGUCY2C mice. 

Small intestine, colon and brain tissues were collected from wild-type mice and homozygous B-NDG hGUCY2C mice and analyzed by IHC with specific-species anti-human GUCY2C antibody (R&D, MAB2157-100). Human GUCY2C was detected in small intestine and colon of B-NDG hGUCY2C mice.

Note: For the use of this antibody, fresh tissue should be used to prepare frozen sections, as formalin-fixed tissue may destroy antigenic epitopes.