FBL Human

Fibrillarin is characterized by an N-terminal repetitive domain rich in glycine and arginine residues, a central RNA-binding domain, and a C-terminal domain that exhibits methyltransferase activity . The enzyme is primarily located in the dense fibrillar component (DFC) of the nucleolus, where it associates with small nucleolar RNAs (snoRNAs) such as U3, U8, and U13 .

The primary function of fibrillarin is to catalyze the 2’-O-methylation of rRNA, a critical step in the maturation and assembly of ribosomes . This methylation process is essential for the proper folding and stability of rRNA, which in turn ensures the accurate translation of genetic information into proteins .

Fibrillarin has been implicated in various diseases, particularly cancer. Studies have shown that the overexpression of fibrillarin is associated with poor prognosis in breast cancer . Interestingly, both hyperactivation and hypoactivation of ribosome biogenesis, mediated by fibrillarin, have been linked to distinct molecular traits in tumors . This dual association suggests that fibrillarin could serve as a valuable biomarker for cancer diagnosis and prognosis .

Additionally, fibrillarin is recognized by antisera from approximately 8% of patients with the autoimmune disease scleroderma, indicating its potential role in autoimmune disorders .

Recombinant fibrillarin is produced using recombinant DNA technology, which involves cloning the FBL gene into an expression vector and introducing it into a host organism, such as bacteria or yeast. The host organism then expresses the fibrillarin protein, which can be purified and used for various research and therapeutic applications.

Recombinant fibrillarin is valuable for studying the enzyme’s structure, function, and interactions with other molecules. It also provides a tool for investigating the molecular mechanisms underlying ribosome biogenesis and its dysregulation in diseases.