MiRNA biogenesis pathway

What is the role of RNA Polymerase II in miRNA biogenesis?

It transcribes the miRNA gene into a primary miRNA (pri-miRNA) transcript.

What characterizes pri-miRNA?

It is a long, single-stranded RNA with a hairpin structure.

What enzymes are involved in the processing of pri-miRNA in the nucleus?

Drosha and its cofactor DGCR8 cleave pri-miRNA into pre-miRNA.

How is pre-miRNA exported from the nucleus?

By Exportin-5.

What does Dicer do in the cytoplasm during miRNA processing?

It cleaves the pre-miRNA to generate a double-stranded mature miRNA.

What is the length of the mature miRNA produced by Dicer?

Approximately 22 nucleotides long.

What happens to the guide strand of mature miRNA in RISC?

It is incorporated into the RNA-Induced Silencing Complex (RISC).

How does RISC-bound miRNA interact with target mRNA?

It binds to complementary sequences, leading to mRNA degradation or translational repression.

What is the function of the RNA-Induced Silencing Complex (RISC)?

It mediates the regulation of target mRNA by the bound miRNA.

What are the potential outcomes of miRNA binding to target mRNA?

mRNA degradation or translational repression.