Molecular Cloning, Characterization, and Dynamics of Rat Formiminotransferase Cyclodeaminase, a Golgi-associated 58-kDa Protein*

摘要: A peripherally associated 58-kDa Golgi protein (58K) of unknown function has been previously described (Bloom, G. S., and Brashear, T. A. (1989) J. Biol. Chem. 264, 16083-16092). To molecularly characterize 58K, we used a monoclonal anti-58K antibody (monoclonal 58K-9) to screen rat liver cDNA expression library. Positive clones were isolated, characterized, partially sequenced. The obtained sequences show high level identity with porcine formiminotransferase cyclodeaminase (FTCD), suggesting that 58K is FTCD. Rat FTCD structurally similar FTCD, metabolic enzyme involved in conversion histidine glutamic acid, exists dimeric, tetrameric, octameric complexes resistant proteolysis. define parameters association the Golgi, comparison its behavior various ER-to-Golgi intermediate compartment marker proteins was examined under specific conditions. results extraction are those GM130, tightly matrix protein. appears be dynamic component proportion molecules cycle between earlier compartments secretory pathway. remains fragments during microtubule disruption not released into cytosol brefeldin treatment. Instead, relocates from but time course redistribution distinct mannosidase II relocation. already dispersed small punctate structures at when still largely localized structures. observed tubules originating containing II. it redistribute vesicles arranged linear "pearls on string" pattern. These suggest relocation temporally spatially provides novel study dynamics.