Golgi Matrix Protein (GM130) is a peripheral cytoplasmic protein that is bound to Golgi membranes. It maintains cis-Golgi structure, and it regulates the disassembly and reassembly of the Golgi complex during mitosis. GM130 may also be important during docking and fusion of coatomer (COPI) coated vesicles to the Golgi membrane. The carboxy-terminal domain of GM130 is highly homologous to the human auto-antigen, golgin-95. GM130 interacts in a GTP-dependent manner with Rab1b protein, a regulator of anterograde traffic between ER and Golgi membranes. It has also been implicated in the activation of Ste-kinase, YSK1, during the golgi reorganization that occurs along with cell migration.