The TBC/RabGAP Armus coordinates Rac1 and Rab7 functions during autophagy.

Autophagy is an evolutionarily conserved process that enables catabolic and degradative pathways. These pathways commonly depend on vesicular transport controlled by Rabs, small GTPases inactivated by TBC/RabGAPs. The Rac1 effector TBC/RabGAP Armus (TBC1D2A) is known to inhibit Rab7, a key regulator of lysosomal function.

Armus is a Rac1 effector that inactivates Rab7 and regulates E-cadherin degradation.

Background: Cell-cell adhesion and intracellular trafficking are regulated by signaling pathways from small GTPases of the Rho, Arf, and Rab subfamilies. How signaling from distinct small GTPases are integrated in a given process is poorly understood.

Results: We find that a TBC/RabGAP protein, Armus, integrates signaling between Arf6, Rac1, and Rab7 during junction disassembly.