rRNA 2'-O-methyltransferase fibrillarin (FBL)

Fibrillarin is a highly conserved nucleolar protein composed of 321 amino acids, featuring a glycine-arginine rich (GAR) N-terminal domain and a central methyltransferase domain[1][2][3][4]. It is an essential enzyme in eukaryotes involved in the 2'-O-methylation of ribosomal RNA during pre-rRNA processing as a core component of box C/D small nucleolar ribonucleoproteins (snoRNPs), aiding ribosome biogenesis and overall nucleolar function[1][2][3][4]. Fibrillarin also participates in phase separation dynamics in the nucleolus, and is implicated in cellular homeostasis, reproduction, immune responses, inflammation, and cancer biology[1][2]. It is an autoantigen in autoimmune scleroderma, and aberrant expression or function is associated with malignancy and altered rRNA modification, which has spurred interest in its potential as a therapeutic target in cancer cell biology[1][2][4].

Other names

FBLFIB1FLRNRNU3IP1Nop134 kDa nucleolar scleroderma antigenHistone-glutamine methyltransferaseU6 snRNA 2'-O-methyltransferase fibrillarinFIBRNA U3 small nucleolar interacting protein 134-kD nucleolar scleroderma antigen

Drugs or molecules targeting FBL would act by inhibiting its methyltransferase activity, modulating rRNA processing, or altering nucleolar phase separation or protein-RNA interactions