Alternative titles; symbols
HGNC Approved Gene Symbol: FBL
Cytogenetic location: 19q13.2 Genomic coordinates (GRCh38): 19:39,834,458-39,846,379 (from NCBI)
Fibrillarin is a component of a nucleolar small nuclear ribonucleoprotein (snRNP) particle thought to participate in the first step in processing preribosomal RNA. In humans, fibrillarin is associated with the U3 (SNORD3A; 180710), U8 (SNORD118; 616663), and U13 (SNORD13; 616664) small nuclear RNAs (summary by Aris and Blobel, 1991).
By screening a hepatoma cDNA library with probes from the fibrillarin gene of S. cerevisiae (Nop1) and Xenopus laevis, Aris and Blobel (1991) isolated a 1.1-kb clone encoding human fibrillarin. The deduced 318-amino acid protein contains an N-terminal repetitive domain of 75 to 80 residues that is rich in arginine and glycine, a putative RNA-binding domain, and an RNP consensus sequence, consistent with its association with small nucleolar RNAs. Human fibrillarin shows a high degree of sequence homology with its yeast and Xenopus counterparts.
When Aris and Blobel (1991) expressed fibrillarin in vitro, it migrated on SDS gels as a 36-kD protein that was specifically immunoprecipitated by antisera from humans with scleroderma autoimmune disease.
Okano et al. (1992) reported that serum antibodies to the U3 small nuclear ribonucleoprotein were highly specific to systemic sclerosis, were found more frequently in blacks, and were associated with skeletal muscle disease and primary pulmonary arterial hypertension.
Hartz (2010) mapped the FBL gene to chromosome 19q13.2 based on an alignment of the FBL sequence (GenBank BT006830) with the genomic sequence (GRCh37).
Aris, J. P., Blobel, G. cDNA cloning and sequencing of human fibrillarin, a conserved nucleolar protein recognized by autoimmune antisera. Proc. Nat. Acad. Sci. 88: 931-935, 1991. [PubMed: 1846968] [Full Text: https://doi.org/10.1073/pnas.88.3.931]
Hartz, P. A. Personal Communication. Baltimore, Md. 7/9/2010.
Okano, Y., Steen, V. D., Medsger, T. A., Jr. Autoantibody to U3 nucleolar ribonucleoprotein (fibrillarin) in patients with systemic sclerosis. Arthritis Rheum. 35: 95-100, 1992. [PubMed: 1731817] [Full Text: https://doi.org/10.1002/art.1780350114]