TY - JOUR TI - Lamellipodin promotes actin assembly by clustering Ena/VASP proteins and tethering them to actin filaments AU - Hansen, Scott D AU - Mullins, R Dyche A2 - Lappalainen, Pekka VL - 4 PY - 2015 DA - 2015/08/21 SP - e06585 C1 - eLife 2015;4:e06585 DO - 10.7554/eLife.06585 UR - https://doi.org/10.7554/eLife.06585 AB - Enabled/Vasodilator (Ena/VASP) proteins promote actin filament assembly at multiple locations, including: leading edge membranes, focal adhesions, and the surface of intracellular pathogens. One important Ena/VASP regulator is the mig-10/Lamellipodin/RIAM family of adaptors that promote lamellipod formation in fibroblasts and drive neurite outgrowth and axon guidance in neurons. To better understand how MRL proteins promote actin network formation we studied the interactions between Lamellipodin (Lpd), actin, and VASP, both in vivo and in vitro. We find that Lpd binds directly to actin filaments and that this interaction regulates its subcellular localization and enhances its effect on VASP polymerase activity. We propose that Lpd delivers Ena/VASP proteins to growing barbed ends and increases their polymerase activity by tethering them to filaments. This interaction represents one more pathway by which growing actin filaments produce positive feedback to control localization and activity of proteins that regulate their assembly. KW - actin KW - membrane KW - single molecule KW - TIRF microscropy KW - cytoskeleton JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -