DIAGNOSTIC GENOMICS Lecture 6: Expression of the Genome – miRNAs and RNA Interference

These flashcards cover key terms and concepts related to the expression of the genome, focusing on regulatory RNAs, mechanisms of RNA interference, and their implications in gene expression and disease.

Functional RNAs

RNAs that are directly involved in biochemical activities, such as mRNA, tRNA, and rRNA.

Regulatory RNAs

RNAs that direct or coordinate activities of other biomolecules; examples include miRNA, siRNA, and lncRNA.

MicroRNA (miRNA)

A type of regulatory RNA, usually 21-22 nucleotides long, that regulates gene expression.

RNA interference (RNAi)

A biological process in which small RNAs (like miRNA and siRNA) repress or silence gene expression.

Drosha

An enzyme that cleaves primary miRNA (pri-miRNA) to produce pre-miRNA in the nucleus.

Dicer

An enzyme that further processes pre-miRNA into mature miRNA in the cytoplasm.

RISC (RNA-induced silencing complex)

A protein and RNA complex that mediates the action of small RNAs to silence target genes.

mRNA turnover

The process of degradation of mRNA molecules, effectively reducing gene expression.

3’ UTR

The untranslated region at the 3' end of an mRNA that is often critical for the regulation of gene expression by miRNAs.

Oncogenes

Genes that have the potential to cause cancer when overexpressed or mutated.

Tumor suppressor genes

Genes that protect a cell from one step on the path to cancer; when these genes are disrupted, cancer can occur.

Chronic lymphocytic leukaemia (CLL)

A type of cancer that often involves the dysregulation of miRNAs, specifically loss of miR-15a/miR-16-1.

EGFR (Epidermal Growth Factor Receptor)

A receptor that is a major driver of colorectal cancer and is targeted by certain therapeutic antibodies.

Seed sequence

The region of a miRNA that is critical for base pairing with its target mRNA, typically bases 2-9 of the miRNA.

mRNA sequestration

The process whereby mRNA targets are sequestered into P-bodies, inhibiting translation.