Hello Gopal,

MicroRNA is a form of small, single-stranded RNA, 18–25 nucleotides long. About half of all currently identified miRNAs are intragenic and processed mostly from introns and relatively few exons of protein coding genes, while the remaining are intergenic, transcribed independently of a host gene and regulated by their own promoters.

Unlike protein coding genes, miRNA after being transcribed, instead of being translated into protein, it regulates the functions of other genes in protein synthesis. Therefore, miRNAs are genes that modulate other protein-coding genes.

MicroRNAs work in RNA silencing by negatively regulating the expression of several genes both at mRNA and protein level, by degrading their mRNA target and/or by silencing translation.

Best.

MicroRNA (miRNA) encoding genes produce non-coding RNA molecules that regulate gene expression post-transcriptionally by binding to target mRNAs while protein-coding genes produce mRNA transcripts that are translated into proteins. MiRNA genes often produce long primary transcripts (pri-miRNAs) processed into precursor miRNAs (pre-miRNAs) and mature miRNAs, whereas protein-coding genes contain exons and introns and undergo transcription, mRNA processing, and translation. The transcription of both types of genes is regulated, but miRNA genes may have distinct regulatory elements. MiRNA biogenesis involves processing steps mediated by specific complexes, leading to mature miRNA incorporation into RNA-induced silencing complexes (RISC). MiRNAs function post-transcriptionally to destabilize or repress the translation of target mRNAs by binding to complementary sequences in their 3' UTRs, while proteins translated from protein-coding genes perform diverse cellular functions. These differences highlight the distinct roles, structures, regulations, biogenesis pathways, and functions of miRNA-encoding genes compared to protein-coding genes.