The tectonic-like complex (also known as the B9 complex) is localized at the transition zone of primary cilia and acts as a barrier that prevents diffusion of transmembrane proteins between the cilia and plasma membranes. The complex is required for hedgehog signalling transduction []. Components of this complex are included in this entry, including tectonic-1 (TCTN1), tectonic-2 (TCTN2) and tectonic-3 (TCTN3). TCTN1 acts as an activation and inhibitor of Hedgehog-mediated patterning of the neural tube []. Mutations in the TCTN3 gene cause Mohr-Majewski syndrome, characterized by abnormalities in the oral cavity, face, and digits [].
