UNIPROT #

P22087

PROTEIN NAME

Fibrillarin

SYNONYMS

34 kD nucleolar scleroderma antigen antibody; 34 kDa nucleolar scleroderma antigen antibody; Fbl antibody; FBRL_HUMAN antibody; FIB antibody; FIB1 antibody; FLRN antibody; Histone-glutamine methyltransferase antibody; Nop1p antibody; RNA U3 small nucleolar interacting protein 1 antibody; RNU3IP1 antibody; rRNA 2' O methyltransferase fibrillarin antibody; rRNA 2'-O-methyltransferase fibrillarin antibody

SEQUENCE SIMILARITIES

Belongs to the methyltransferase superfamily. Fibrillarin family.

POST-TRANSLATIONAL MODIFICATION

Ubiquitinated. Ubiquitination leads to proteasomal degradation. Deubiquitinated by USP36.; By homology to other fibrillarins, some or all of the N-terminal domain arginines are modified to asymmetric dimethylarginine (DMA).; Acetylated by CREBBP/CBP, preventing methylation of 'Gln-105' of histone H2A (H2AQ104me), without affecting rRNA methylation. Deacetylation by SIRT7 restores methylation of 'Gln-105' of histone H2A (H2AQ104me).

SUBCELLULAR LOCATION

Nucleus.

FUNCTION

Fibrillarin is a widely occurring, basic, nonhistone protein that is localized exclusively in the fibrillar region of the nucleolus, including both the dense fibrillar and the fibrillar center regions. Fibrillarin is also expressed in HeLa cells, 3T3 cells, and human peripheral blood lymphocytes. In metaphase and anaphase, fibrillarin is found on putative chromosomal nucleolar regions (NORs). During telophase, fibrillarin is an early marker for the site of the newly forming nucleolus. The structure of fibrillarin includes an RNA-binding domain and an RNP consensus sequence, which is consistent with the association of fibrillarin with the U3 small nucleolar RNA. Fibrillarin is involved in processing rRNA transcripts in the nucleolus.