Fibrillarin (FBL) Antibody – Mouse Monoclonal

This gene product is a component of a nucleolar small nuclear ribonucleoprotein (snRNP) particle thought to participate in the first step in processing preribosomal RNA. It is associated with the U3, U8, and U13 small nuclear RNAs and is located in the dense fibrillar component (DFC) of the nucleolus. The encoded protein contains an N-terminal repetitive domain that is rich in glycine and arginine residues, like fibrillarins in other species. Its central region resembles an RNA-binding domain and contains an RNP consensus sequence. Antisera from approximately 8% of humans with the autoimmune disease scleroderma recognize fibrillarin. [provided by RefSeq, Jul 2008]

Function: Involved in pre-rRNA processing. Utilizes the methyl donor S-adenosyl-L-methionine to catalyze the site-specific 2'-hydroxyl methylation of ribose moieties in pre-ribosomal RNA. Site specificity is provided by a guide RNA that base pairs with the substrate. Methylation occurs at a characteristic distance from the sequence involved in base pairing with the guide RNA.

Subunit structure: Interacts with NOLC1

By similarity. Component of box C/D small nucleolar ribonucleoprotein (snoRNP) particles that contain NHP2L1, FBL, NOP5 and NOP56, plus a guide RNA. It is associated with the U3, U8, U13, X and Y small nuclear RNAs. Component of several ribosomal and nucleolar protein complexes. Interacts with PRMT5 and UTP20. Interacts with DDX5 and C1QBP. Ref.9 Ref.10 Ref.11 Ref.12 Ref.13 Ref.17

Subcellular location: Nucleus › nucleolus. Note: Fibrillar region of the nucleolus. Ref.2 Ref.9 Ref.12

Post-translational modification: By homology to other fibrillarins, some or all of the N-terminal domain arginines are modified to asymmetric dimethylarginine (DMA).

Sequence similarities: Belongs to the methyltransferase superfamily. Fibrillarin family.