Non coding RNA types, features and function. miRNA, siRNA, lncRNA, piRNA, snRNA, snoRNA, rRNA, tRNA.

Summary

This video explores the diverse world of non-coding RNAs (ncRNAs) and their vital roles in cellular processes. While previously considered 'junk,' ncRNAs like rRNA, tRNA, miRNA, siRNA, piRNA, snRNA, snoRNA, and lncRNA are crucial for functions such as protein synthesis, gene regulation, and RNA processing. The video delves into how these non-coding molecules contribute to processes like transcriptional regulation, gene silencing, and epigenetic modifications, underscoring their biological significance in maintaining cellular function and overall genome stability.

Takeaways

• 😀 The genome consists of genes and intergenic regions, the latter once considered 'junk' but now understood to have biological significance.
• 😀 Non-coding RNA (ncRNA) refers to RNA that does not code for proteins, but still plays crucial roles in cellular processes.
• 😀 Ribosomal RNA (rRNA) makes up over 80% of the total RNA in cells and is essential for protein synthesis, forming part of the ribosome.
• 😀 Transfer RNA (tRNA) has two key functions: decoding mRNA and delivering amino acids to the ribosome for protein synthesis.
• 😀 MicroRNA (miRNA) regulates gene expression by binding to target mRNA, leading to mRNA degradation or translation inhibition.
• 😀 Short interfering RNA (siRNA) plays a role in RNA interference, silencing genes by cleaving target mRNA.
• 😀 Piwi-interacting RNA (piRNA) regulates transcription and silences transposons, working with Piwi proteins to target transposon transcripts.
• 😀 Small nuclear RNA (snRNA) is involved in processing pre-mRNA and regulating transcription factors, with key roles in splicing and telomere maintenance.
• 😀 Small nucleolar RNA (snoRNA) is responsible for the chemical modification of other RNA molecules through methylation and pseudo-uridylation.
• 😀 Long non-coding RNA (lncRNA), often over 200 nucleotides long, regulates gene expression and can influence splicing, epigenetics, and transcriptional control.

Q & A

What are non-coding RNAs, and why are they significant?

Non-coding RNAs (ncRNAs) are RNA molecules that do not encode proteins but play crucial roles in cellular functions. Despite not coding for proteins, they are involved in various regulatory and structural functions within the cell, making them biologically significant.

Why were non-coding regions of the genome once considered 'junk'?

Non-coding regions were once considered 'junk' because they do not directly code for proteins. However, further research has revealed that many non-coding RNAs perform vital regulatory and functional roles in the cell.

What is the role of ribosomal RNA (rRNA) in the cell?

Ribosomal RNA (rRNA) makes up more than 80% of the total cellular RNA and is essential for protein synthesis. It forms the structure of ribosomes and assists in translating mRNA into proteins. It also interacts with transfer RNA (tRNA) during protein synthesis.

How does transfer RNA (tRNA) assist in protein synthesis?

Transfer RNA (tRNA) decodes the information carried by messenger RNA (mRNA) by matching its anticodon with the corresponding codon on the mRNA. It also carries the appropriate amino acid to the ribosome for protein chain elongation.

What is the significance of microRNAs (miRNAs) in gene regulation?

MicroRNAs (miRNAs) are small RNA molecules that regulate gene expression by binding to target mRNA molecules. They inhibit mRNA translation or lead to mRNA degradation, playing a crucial role in controlling gene expression.

What is the difference between miRNAs and siRNAs?

MiRNAs (microRNAs) are endogenously produced and regulate gene expression by binding to mRNA, whereas siRNAs (short interfering RNAs) are typically exogenous and are used in RNA interference technology to silence genes through mRNA cleavage.

What role do piRNAs play in the cell?

PiRNAs (PIWI-interacting RNAs) are involved in regulating transcription and silencing transposons. They interact with PIWI proteins to guide them to transposon transcripts, helping to maintain genome stability.

How do small nuclear RNAs (snRNAs) function in the cell?

Small nuclear RNAs (snRNAs) are involved in processing pre-mRNA in the nucleus. They form part of the spliceosome complex, which is responsible for splicing mRNA. Additionally, snRNAs play roles in transcription factor regulation and telomere maintenance.

What is the role of small nucleolar RNAs (snoRNAs)?

Small nucleolar RNAs (snoRNAs) guide the chemical modification of other RNA molecules, such as rRNA, tRNA, and snRNA, mainly through methylation or pseudouridylation. They are critical for the proper processing and function of these RNAs.

What are long non-coding RNAs (lncRNAs), and what is their function?

Long non-coding RNAs (lncRNAs) are RNA molecules that are over 200 nucleotides long and do not code for proteins. They can regulate gene expression by interacting with other RNA molecules, splicing factors, and chromatin remodeling complexes, and they may also contribute to epigenetic changes.