Rat liver cytosolic 4 S polycyclic aromatic hydrocarbon-binding protein is glycine N-methyltransferase.

摘要: In the rat, cytochrome P-450IA1 gene expression, which is most closely associated with aryl hydrocarbon hydroxylase activity, thought to be regulated by several trans-acting factors, including 4 S polycyclic aromatic (PAH)-binding protein. This protein has been purified homogeneity from rat liver using ion exchange, gel permeation, hydrophobic interaction, and affinity chromatographies. Partial sequencing of 33-kDa band indicated its identity as glycine N-methyltransferase (GNMT). Polyclonal antibodies GNMT immunoprecipitated PAH-binding activity cytosol. Methyltransferase activities copurified during course purification. PAH binding were colocalized in various cytosolic fractions. These data all indicate that are one same or very similar proteins. Western blot analyses yielded a positive signal under denaturing (33 kDa) nondenaturing (150 kDa, tetramer) conditions; also was an oligomer. detected immunohistochemistry nuclei H4IIE hepatoma cells liver. The localization accordance role modulating expression.