Scientists had recently developed a new technique to understand the role of the RNA-cleaving protein DROSHA in genes. The research also records the important happening and the full description of the Molecular Cell.

The cells of the body are composed of a group of sophisticated mechanisms that controls the genes that are not expressed at any given time. According to, this process is possible due to the coordination of several types of RNA molecules, like microRNAs (miRNAs). Such process is being done through the help of DROSHA.

DROSHA protein is the one who catalyzes the initial processing step of microRNA (miRNA) synthesis. This protein splits into the stem loop structure from the primary microRNA (pri-miRNA) in the nucleus, giving way the precursor miRNA (pre-miRNA). It is then moved to the cytoplasm for further processing.

In a human cell line lacking a functional copy of this gene facilitated by DROSHA, canonical miRNA synthesis is reduced. Likewise, somatic mutations in this gene have been observed in human patients with kidney cancer.

Per NCBI, the study is the first genomic-scale analysis of DROSHA cleavage sites on pri-miRNA. "fCLIP-seq stands for formaldehyde crosslinking, immunoprecipitation, and sequencing. By treating the cells with formaldehyde, we manage to preserve the bond between DROSHA protein and its RNA binders," Kim Baekgyu, the first author of the fCLIP-seq that analyzes the miRNA fragments created by the RNA-cleaving protein DROSHA, said. "This result not only serves as a good database for miRNA research but also deepens our understanding of miRNA generation," Kim added.

A vital and ancient component of gene regulation, miRNA tunes the expression of as many as 30-60% of mammalian protein-encoding genes, usually silencing them. Over 2,000 miRNAs are present in human cells, with various of crucial roles in development, cell differentiation, cell division, cell death, and cancer development.

Moreover, mature miRNAs are short RNA molecules, with more or less 22 nucleotides in length, derived from a multi-step process that begins with longer RNA fragments called primary miRNAs (pri-miRNAs) were DROSHA's function is to cut these pri-miRNAs into shorter pieces.

The research team identified hundreds of cleavage sites on pri-miRNAs, including new information not found even in the world's largest miRNA database, miRBase. They also discovered that DROSHA cuts dozens of non-pri-miRNA targets, suggesting new possible functions of the protein that would be interesting to explore further.