After AdipoRl and AdipoR2, T-cadherin
was the third adiponectin receptor described.
 reported the existence of third adiponectin receptor, T-cadherin. The protein is expressed mainly in the vascular endothelial cells and smooth muscles.
Lodish, "T-cadherin is a receptor for hexameric and high-molecular-weight forms of Acrp30/adiponectin," Proceedings of the National Academy of Sciences of the United States of America, vol.
Adiponectin is known to bind 3 receptors: adiponectin receptor 1 (AdipoR1), adiponectin receptor 2 (AdipoR2), and T-cadherin. AdipoR1 and AdipoR2 were isolated from a human skeletal muscle cDNA library with AdipoR2 showing >60% homology to AdipoR1 .
High molecular weight forms of adiponectin can bind to T-cadherin, which is traditionally thought of as a receptor that binds low-density lipoprotein (LDL) with signaling cascades related to cell growth, proliferation, and migration.
The primers of adiponectin were 5'-TATTGGTCCTAAGGGAGACATCGC-3' and 5'-TTTTGGTGATACTACCGAGGTGAC-3'; for adipoR1 5'CTGACTGGCTAAAGGACAACGACTA-3' and 5'-TCGTAG AAGGCGTAAGTATGTCTT-3'; for adipoR2 5'-CGAAACC CGTCATTCAGCAGT-3' and 5'-TTACCTTCCGACCGAA CCTAC-3'; for T-cadherin 5'-TGTGGGTTAGTATTGGTGT ATGTATGAGT-3' and 5'-TTTGATTCTGTGGACTTGGGA GGTC-3'.
By using real-time PCR, we found that endothelial cells express the mRNA of adiponectin, adipoR1 and adipoR2, but not T-cadherin. The expression of adipoR1 was greater than that of adipoR2.
Four types of receptors for APN have been identified, including ADIPOR1, ADIPOR2, T-cadherin
, and calreticulin/CD91.
The researchers discovered that endothelial cells secrete nitric oxide, while smooth muscle cells use the protein T-cadherin
to interact with the neural crest, specialized embryonic cells that give rise to portions of the nervous system and other organs.
Several adiponectin binding proteins have been identified, including AdipoR1, AdipoR2, T-cadherin
, and calreticulin.
Ranscht and colleagues engineered mice that lacked T-cadherin
and looked at their hearts.
In addition, T-cadherin
has also been reported to serve as a receptor for highorder multimers of adiponectin .