The B regulatory subunit might modulate substrate selectivity and catalytic activity, and also might direct the localization of the catalytic enzyme to a particular subcellular compartment.
Subcellular locations: Cytoplasm, Nucleus, Chromosome, Centromere
From mitotic prophase to metaphase, localizes at the inner centromere between a pair of sister kinetochores. Decreased expression at the onset of anaphase.
Widely expressed with the highest expression in heart and skeletal muscle.