
@article {62769,
	title = {A composition-dependent molecular clutch between T cell signaling condensates and actin.},
	journal = {Elife},
	volume = {8},
	year = {2019},
	month = {2019 Jul 03},
	abstract = {<p>During T cell activation, biomolecular condensates form at the immunological synapse (IS) through multivalency-driven phase separation of LAT, Grb2, Sos1, SLP-76, Nck, and WASP. These condensates move radially at the IS, traversing successive radially-oriented and concentric actin networks. To understand this movement, we biochemically reconstituted LAT condensates with actomyosin filaments. We found that basic regions of Nck and N-WASP/WASP promote association and co-movement of LAT condensates with actin, indicating conversion of weak individual affinities to high collective affinity upon phase separation. Condensates lacking these components were propelled differently, without strong actin adhesion. In cells, LAT condensates lost Nck as radial actin transitioned to the concentric network, and engineered condensates constitutively binding actin moved aberrantly. Our data show that Nck and WASP form a clutch between LAT condensates and actin in vitro and suggest that compositional changes may enable condensate movement by distinct actin networks in different regions of the IS.</p>
},
	issn = {2050-084X},
	doi = {10.7554/eLife.42695},
	author = {Ditlev, Jonathon A and Vega, Anthony R and K{\"o}ster, Darius Vasco and Su, Xiaolei and Tani, Tomomi and Lakoduk, Ashley M and Vale, Ronald D and Mayor, Satyajit and Jaqaman, Khuloud and Rosen, Michael K}
}
@article {29827,
	title = {Transmembrane Pickets Connect Cyto- and Pericellular Skeletons Forming Barriers to Receptor Engagement.},
	journal = {Cell},
	volume = {172},
	year = {2018},
	month = {2018 Jan 11},
	pages = {305-317.e10},
	abstract = {<p>Phagocytic receptors must diffuse laterally to become activated upon clustering by multivalent targets. Receptor diffusion, however, can be obstructed by transmembrane proteins ("pickets") that are immobilized by interacting with the cortical cytoskeleton. The molecular identity of these pickets and their role in\&nbsp;phagocytosis have not been defined. We used single-molecule tracking to study the interaction between Fcγ receptors and CD44, an abundant transmembrane protein capable of indirect association with F-actin, hence likely to serve as a picket. CD44 tethers reversibly to formin-induced actin filaments, curtailing receptor diffusion. Such linear filaments predominate in the trailing end of polarized macrophages, where receptor mobility was minimal. Conversely, receptors were most mobile at the leading edge, where Arp2/3-driven actin branching predominates. CD44 binds hyaluronan, anchoring a pericellular coat that also limits receptor displacement and obstructs access to phagocytic targets. Force must be applied to traverse the pericellular barrier, enabling receptors to engage their targets.</p>
},
	issn = {1097-4172},
	doi = {10.1016/j.cell.2017.12.023},
	author = {Freeman, Spencer A and Vega, Anthony and Riedl, Magdalena and Collins, Richard F and Ostrowski, Phillip P and Woods, Elliot C and Bertozzi, Carolyn R and Tammi, Markku I and Lidke, Diane S and Johnson, Pauline and Mayor, Satyajit and Jaqaman, Khuloud and Grinstein, Sergio}
}
