Homologs
In 2004, a protein homologous to cingulin was discovered and named JACOP (also known as paracingulin, or cingulin-like 1 protein; CGNL1). Unlike cingulin, paracingulin is detected both at tight and adherens junctions. The function of paracingulin was clarified when it was discovered that epithelial cells depleted of paracingulin show increased RhoA activation at confluence, and delayed tight junction assembly in the experimental model of the "calcium switch". The delay in junction assembly correlates with decreased Rac1 activation. In fact, similarly to cingulin, paracingulin contributes to recruiting and inactivating the RhoA guanine exchange factor GEF-H1 to junctions. In addition, paracingulin interacts with and recruits to junctions the Rac1 guanine exchange factor Tiam1.
Read more about this topic: Cingulin