Fig. 7: A schematic model for actin disassembly via TM9SF4.
From: TM9SF4 is an F-actin disassembly factor that promotes tumor progression and metastasis
A schematic model is proposed based on the present findings. Upper left, top view; lower left, side view; right, schematics. a typically, cofilin can bind to F-actin at the pointed end and sever actin/ADP monomers from the end. This process is relatively slow and low-efficient. b TM9SF4 is cleaved to release its N-terminal fragment (NTF) into cytosol. The TM9SF4 NTF contains an actin binding site and redox domain. It binds to F-actin, induces actin oxidation and change the stability of actin structure. Such structural change enhances cofilin’s severing activity to cause a rapid actin depolymerization. This TM9SF4-mediated actin disassembly affects cell adhesion and cell motility.
