The Myosin IXb motor activity targets the myosin IXb RhoGAP domain as cargo to sites of actin polymerization.

Myosin IXb (Myo9b) is a single-headed processive myosin that exhibits Rho GTPase-activating protein (RhoGAP) activity in its tail region. Using live cell imaging, we determined that Myo9b is recruited to extending lamellipodia, ruffles, and filopodia, the regions of active actin polymerization. A functional motor domain was both necessary and sufficient for targeting Myo9b to these regions.

Structure and duration of contact between dendritic cells and T cells are controlled by T cell activation state.

The adaptive immune response is initiated when naive T cells interact with dendritic cells (DC). However, the physicodynamics as well as the molecules that constitute the contact plane (immunological synapse) between DC and T cells are not well understood. We show here that for the formation of stable conjugates, T cells need to be preactivated by DC in a CD80/86- and antigen dose-dependent manner.