Non-coding RNA & RNA Interference – Vocabulary Flashcards

Vocabulary flashcards covering key terms, molecules, enzymes, and therapeutic applications related to non-coding RNA, microRNA, and RNA interference.

Non-coding RNA (ncRNA)

RNA molecules that are transcribed but not translated into protein; many regulate gene expression.

microRNA (miRNA)

Endogenous ~22-nt hairpin-derived RNA that guides RISC to repress or degrade complementary mRNA.

Small interfering RNA (siRNA)

~21–23-nt double-stranded RNA (natural or synthetic) that triggers sequence-specific mRNA degradation via RNAi.

RNA interference (RNAi)

Cellular mechanism in which dsRNA initiates sequence-specific silencing of gene expression at the mRNA level.

Double-stranded RNA (dsRNA)

Two complementary RNA strands forming a duplex; essential trigger and substrate for RNAi.

Dicer

RNase III endonuclease that cleaves dsRNA into siRNA/miRNA duplexes and initiates RNAi.

RNA-Induced Silencing Complex (RISC)

Multi-protein complex that, loaded with a guide RNA strand, cleaves or represses target mRNA.

Argonaute (AGO)

Endonuclease core of RISC that performs guide-RNA-directed cleavage of complementary mRNA.

TRBP

Transactivation response element RNA-binding protein; Dicer co-factor aiding miRNA processing.

Gene silencing

Reduction or elimination of gene expression, often via mRNA degradation or translation repression.

Antisense RNA

RNA strand complementary to a sense mRNA that can hybridise and inhibit its translation or stability.

Natural antisense transcription (NAT)

Endogenous production of antisense RNA from the opposite strand (cis) or a distant locus (trans) of a gene.

Long non-coding RNA (lncRNA)

200-nt ncRNA class that modulates diverse cellular processes, often in a cell-type-specific manner.

Piwi-interacting RNA (piRNA)

26–31-nt small RNA that binds Piwi proteins to maintain germ-line genome stability.

Small nucleolar RNA (snoRNA)

60–300-nt RNA species that guide chemical modification and processing of ribosomal RNA.

Small nuclear RNA (snRNA)

~150-nt RNA component of the spliceosome, essential for pre-mRNA splicing.

Chalcone synthase (CHS) co-suppression

Unexpected simultaneous silencing of transgene and endogenous CHS in petunias, early evidence of RNAi.

lin-4 microRNA

First discovered miRNA (in C. elegans) that down-regulates lin-14 mRNA to control developmental timing.

lin-14 mRNA

C. elegans transcript whose 3′UTR contains sites complementary to lin-4 miRNA; repressed during development.

Caenorhabditis elegans (C. elegans)

Model nematode organism pivotal for the discovery of RNAi and microRNA biology.

Promoter

DNA sequence where RNA polymerase binds to initiate transcription of a gene.

Enhancer

Regulatory DNA element that increases transcription levels of associated genes, often via TF binding.

Transcription factor

Protein that binds specific DNA sequences to regulate the rate of gene transcription.

Chromatin

DNA–protein complex whose structural modifications (e.g., histone acetylation) influence gene expression.

DNA methylation

Covalent addition of methyl groups to DNA, usually repressing transcription.

Ribosome

Ribonucleoprotein machine that translates mRNA codons into a polypeptide chain.

Initiation factors

Proteins that assist ribosome assembly on mRNA to start translation.

Post-translational modification

Chemical alteration of proteins (e.g., phosphorylation, ubiquitination) that affects function and stability.

Ubiquitination

Attachment of ubiquitin to proteins, marking them for degradation by the proteasome.

Phosphorylation

Addition of a phosphate group to proteins, modulating activity, localisation or interactions.

Givosiran

Approved siRNA drug that targets hepatic ALAS1 to treat acute intermittent porphyria.

Patisiran

First FDA-approved RNAi therapeutic; siRNA against transthyretin for hereditary amyloidosis.

Fitusiran

GalNAc-conjugated siRNA in clinical trials that lowers antithrombin levels to treat haemophilia.

Inclisiran

Investigational siRNA targeting PCSK9 to reduce low-density lipoprotein cholesterol levels.