Answer :
Final answer:
The protein that works with dsRNA binding protein DGCR8 to cleave mRNA and produce pre-miRNA in the nucleus is Drosha. Drosha is part of the Microprocessor complex essential for the initial processing of miRNAs, which are key regulators of gene expression. Option B is correct.
Explanation:
In the nucleus, the protein that associates with dsRNA binding protein DGCR8 to cleave mRNA at stem-loops, producing pre-miRNA, is Drosha. Drosha is part of the Microprocessor complex and is responsible for the initial processing of primary microRNAs (pri-miRNAs) into precursor microRNAs (pre-miRNAs) before they are further processed into mature miRNAs by Dicer in the cytoplasm.
The pre-miRNAs are then loaded onto the RISC (RNA-induced silencing complex), which mediates gene silencing through mRNA degradation or translation inhibition. Drosha plays a crucial role in the miRNA pathway, as it chops the pri-miRNAs into pre-miRNAs which are essential for gene regulation.
