M-Sec promotes membrane nanotube formation by interacting with Ral and the exocyst complex

How tunnelling nanotubes form between cells is unclear. A mammalian protein, M-Sec, that has homology to the Sec6 subunit of the exocyst complex, is sufficient and necessary for nanotube formation. The Ral GTPase and its effector, the exocyst complex, are required for M-Sec-dependent regulation of nanotubes.