rRNA 2'-O-methyltransferase fibrillarin is an enzyme that in humans is encoded by the FBLgene.
This gene product is a component of a nucleolar small nuclear ribonucleoprotein (snRNP) particle thought to participate in the first step in processing pre-ribosomal (r)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.
Fibrillarin is associated with U3, U8 and U13 small nuclear RNAs in mammals and is similar to the yeast NOP1 protein. Fibrillarin has a well conserved sequence of around 320 amino acids, and contains 3 domains, an N-terminal Gly/Arg-rich region; a central domain resembling other RNA-binding proteins and containing an RNP-2-like consensus sequence; and a C-terminal alpha-helical domain. An evolutionarily related pre-rRNA processing protein, which lacks the Gly/Arg-rich domain, has been found in various archaebacteria.
A study by Schultz et al. indicated that the K-turn binding 15.5-kDa protein (called Snu13 in yeast) interacts with spliceosome proteins hPRP31, hPRP3, hPRP4, CYPH and the small nucleolar ribonucleoproteins NOP56, NOP58, and fibrillarin. The 15.5-kDa protein has sequence similarity to other RNA-binding proteins such as ribosomal proteins S12, L7a, and L30 and the snoRNP protein NHP2. The U4/U6 snRNP contains 15.5-kDa protein. The 15.5-kDa protein also exists in a ribonucleoprotein complex that binds the U3 box B/C motif. The 15.5-kDa protein also exists as one of the four core proteins of the C/D small nucleolar ribonucleoprotein that mediates methylation of pre-ribosomal RNAs.
^Nicol, S M; Causevic M; Prescott A R; Fuller-Pace F V (June 2000). "The nuclear DEAD box RNA helicase p68 interacts with the nucleolar protein fibrillarin and colocalizes specifically in nascent nucleoli during telophase". Exp. Cell Res. (UNITED STATES) 257 (2): 272–80. doi:10.1006/excr.2000.4886. ISSN0014-4827. PMID10837141.
Okano Y, Steen VD, Medsger TA (1992). "Autoantibody to U3 nucleolar ribonucleoprotein (fibrillarin) in patients with systemic sclerosis". Arthritis Rheum.35 (1): 95–100. doi:10.1002/art.1780350114. PMID1731817.
Lischwe MA, Ochs RL, Reddy R et al. (1985). "Purification and partial characterization of a nucleolar scleroderma antigen (Mr = 34,000; pI, 8.5) rich in NG,NG-dimethylarginine". J. Biol. Chem.260 (26): 14304–10. PMID2414294.
Magoulas C, Zatsepina OV, Jordan PW et al. (1998). "The SURF-6 protein is a component of the nucleolar matrix and has a high binding capacity for nucleic acids in vitro". Eur. J. Cell Biol.75 (2): 174–83. doi:10.1016/s0171-9335(98)80059-9. PMID9548374.
Ai LS, Lin CH, Hsieh M, Li C (1999). "Arginine methylation of a glycine and arginine rich peptide derived from sequences of human FMRP and fibrillarin". Proc. Natl. Sci. Counc. Repub. China B23 (4): 175–80. PMID10518318.
Nicol SM, Causevic M, Prescott AR, Fuller-Pace FV (2000). "The nuclear DEAD box RNA helicase p68 interacts with the nucleolar protein fibrillarin and colocalizes specifically in nascent nucleoli during telophase". Exp. Cell Res.257 (2): 272–80. doi:10.1006/excr.2000.4886. PMID10837141.
Pellizzoni L, Baccon J, Charroux B, Dreyfuss G (2001). "The survival of motor neurons (SMN) protein interacts with the snoRNP proteins fibrillarin and GAR1". Curr. Biol.11 (14): 1079–88. doi:10.1016/S0960-9822(01)00316-5. PMID11509230.
Zhou X, Tan FK, Xiong M et al. (2001). "Systemic sclerosis (scleroderma): specific autoantigen genes are selectively overexpressed in scleroderma fibroblasts". Journal of Immunology167 (12): 7126–33. doi:10.4049/jimmunol.167.12.7126. PMID11739535.
Cimato TR, Tang J, Xu Y et al. (2002). "Nerve growth factor-mediated increases in protein methylation occur predominantly at type I arginine methylation sites and involve protein arginine methyltransferase 1". J. Neurosci. Res.67 (4): 435–42. doi:10.1002/jnr.10123. PMID11835310.
Fujiyama S, Yanagida M, Hayano T et al. (2002). "Isolation and proteomic characterization of human Parvulin-associating preribosomal ribonucleoprotein complexes". J. Biol. Chem.277 (26): 23773–80. doi:10.1074/jbc.M201181200. PMID11960984.
Whitehead SE, Jones KW, Zhang X et al. (2003). "Determinants of the interaction of the spinal muscular atrophy disease protein SMN with the dimethylarginine-modified box H/ACA small nucleolar ribonucleoprotein GAR1". J. Biol. Chem.277 (50): 48087–93. doi:10.1074/jbc.M204551200. PMID12244096.
Herrera-Esparza R, Kruse L, von Essen M et al. (2003). "U3 snoRNP associates with fibrillarin a component of the scleroderma clumpy nucleolar domain". Arch. Dermatol. Res.294 (7): 310–7. doi:10.1007/s00403-002-0338-7. PMID12373336.