Spatio-temporal control is critical for RAC1 signaling. In this week’s online issue of Molecular Cell the group of Dr. Christian Behrends report the identification of CUL3-KBTBD6/KBTBD7 as ubiquitin ligase that locally regulates the abundance of the guanine exchange factor TIAM1.

Furthermore, membrane targeting of CUL3-KBTBD6/KBTBD7 is mediated by GABARAP proteins, thereby establishing functions of this subfamily of human ATG8 proteins beyond autophagy and membrane trafficking.