Calsyntenin

Calsyntenins (Csts, CLSTN) are type I transmembrane proteins that belong to the cadherin superfamily. Their name comes from their ability to bind Calcium. In birds and mammals, they consist of three family members (Cst1, 2 and 3), in nematodes one ortholog (CASY-1, originally CDH-11) is known. Calsyntenins are also termed Alcadeins.

Cst1 (CLSTN1) was first shown to be predominantly expressed in postsynaptic membranes of excitatory neurons, Cst2 and 3 were found in an increased manner in inhibitory GABAergic neurons. The Calsyntenins were shown to interact with numerous proteins such as with kinesin-1 and the APP-linker protein X11L/Mint2, , ) and were shown to have multi-purpose functions within and outside the nervous system , , , ,.

When the Calsyntenins were discovered, a rule in regulation of the postsynaptic calcium concentration was first described. Later it was found that another key-function is to link vesicles to kinesin light chain (KLC) and thus to co-determine transport of distinct cargo,.