Transmembrane Pickets Connect Cyto- and Pericellular Skeletons Forming Barriers to Receptor Engagement.
Cell
; 172(1-2): 305-317.e10, 2018 01 11.
Article
in En
| MEDLINE
| ID: mdl-29328918
ABSTRACT
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 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.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Actin Cytoskeleton
/
Receptors, Immunologic
/
Cell Membrane
/
Hyaluronan Receptors
Limits:
Adult
/
Animals
/
Female
/
Humans
/
Male
Language:
En
Journal:
Cell
Year:
2018
Type:
Article
Affiliation country:
Canada