5b86

Publication Abstract from PubMed

The tunneling nanotube (TNT) is a structure used for intercellular communication, and is a thin membrane protrusion mediating transport of various signaling molecules and cellular components. M-Sec has potent membrane deformation ability and induces TNT formation in cooperation with the Ral/exocyst complex. Here, we show that the N-terminal polybasic region of M-Sec directly binds phosphatidylinositol (4,5)-bisphosphate for its localization to the plasma membrane during the initial stage of TNT formation. We further report a crystal structure of M-Sec, which consists of helix bundles arranged in a straight rod-like shape, similar to the membrane tethering complex subunits. A positively charged surface in the C-terminal domains is required for M-Sec interaction with active RalA to extend the plasma membrane protrusions. Our results suggest that the membrane-associated M-Sec recruits active RalA, which directs the exocyst complex to form TNTs.

Distinct Roles for the N- and C-terminal Regions of M-Sec in Plasma Membrane Deformation during Tunneling Nanotube Formation.,Kimura S, Yamashita M, Yamakami-Kimura M, Sato Y, Yamagata A, Kobashigawa Y, Inagaki F, Amada T, Hase K, Iwanaga T, Ohno H, Fukai S Sci Rep. 2016 Sep 15;6:33548. doi: 10.1038/srep33548. PMID:27629377^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.