Golgin B1 (GOLGB1)

The antibody stained Golgi specifically in several human tissues, as well as in rat, hamster, mouse, and chicken cells. On Western blots, the antibody recognized a 400-kD protein, dubbed 'giantin' because of its large size. Giantin is not extracted from the membrane by high salt, urea, alkaline carbonate, or Triton X-100 (nonionic detergent) treatment, suggesting that it is an integral component of the Golgi membrane that is associated with the cytoskeleton. Protease digestion experiments suggest that giantin has a large (at least 350 kD) cytoplasmic domain. The predicted pI is 4.77, and the protein contains a high fraction of alpha-helical domains with heptad repeats that can form coiled-coils. On Western blots, the antibodies recognize 320- and 380-kD proteins. Anti-macrogolgin antibodies were found in 11% of HIV-positive patients.