FunctionComponent of the 60-80S U3 small nucleolar ribonucleoprotein (U3 snoRNP). Required for the early cleavages during pre-18S ribosomal RNA processing.
Sequence similaritiesBelongs to the MPP10 family.
Post-translational modificationsPhosphorylated in M (mitotic) phase.
Cellular localizationNucleus > nucleolus. Chromosome. Fibrillar region of the nucleolus. After dissolution of the nucleolus in early M phase becomes associated with chromosomes through metaphase and anaphase. In telophase localized to small cellular prenucleolar bodies that not always contain fibrillarin. The reassociation with nucleolus is preceeded by the arrival of fibrillarin.