A study published in PNAS by the CIB team led by Miguel Angel Peñalva provides a satisfactory explanation to a long-standing question in the field of intracellular traffic. The RAB GTPases, RAB1 and RAB11, act sequentially to regulate traffic across the Golgi. Somewhat paradoxically, they are both are activated by TRAPP, a multi-subunit GDPexchange factor (GEF). TRAPP comes in three versions sharing the same core subunits. How the RAB specificity of each of these versions is determined was a disputed issue. By combining the resolving power of classical genetics with 4Dmicroscopy and biochemical assays, the CIB group unequivocally demonstrates that TRAPPII acts in vivo on RAB11, which is the major determinant of post-Golgi identity. Thus, TRAPPII action marks, and possibly determines, the Golgi-to-post-Golgi transition.
Research
05 Oct 2016
Golgi exit through TRAPP-y ground