BD Transduction Laboratories™ Purified Mouse Anti-GBF1

The Golgi apparatus is a complex and dynamic organelle that functions in protein sorting and modification. Numerous structural and regulatory proteins are involved in the budding, docking, and fusion of Golgi-directed vesicles. Golgi-specific Brefeldin A (BFA)-resistance Factor (GBF1) is a guanine nucleotide exchange factor that contains a centrally located Sec7 domain, and a proline-rich region at the C-terminus. The Sec7 domain is commonly found in a variety of secretory proteins, and is required for activation of ARFs. GBF1 mRNA is ubiquitously expressed, and GBF1 protein localizes to the Golgi, as well as to perinuclear structures that contain COPI. BFA is a fungal heterocyclic lactone that disrupts membrane recruitment of ARFs. This action blocks protein secretion, and changes the morphology of various organelles, such as the Golgi. Overexpression of GBF1 suppresses BFA-induced changes in Golgi morphology, ARF activation, and coat protein recruitment. GBF1 interacts preferentially with ARF5 in the presence of Mg2+. Thus, GBF1 is a Golgi-specific guanine nucleotide exchange factor that activates ARFs through a mechanism that interferes with BFA action.