ncRNAs - all types of non-coding RNA (lncRNA, tRNA, rRNA, snRNA, snoRNA, siRNA, miRNA, piRNA)

Henrik's Lab

31 May 202105:43

Summary

TLDRThis video script delves into the diverse world of non-coding RNAs, which, despite not encoding proteins, play crucial roles in various cellular processes. It highlights the importance of transfer RNA in translation, the housekeeping function of ribosomal RNA, and the regulatory roles of small nuclear and nucleolar RNAs in splicing and RNA modification. The script also explores the protective mechanism of RNA interference through small interfering RNAs and microRNAs, and the gene-silencing capabilities of piRNAs. Finally, it touches on the complex functions of long non-coding RNAs, including their involvement in gene regulation and diseases like cancer.

Takeaways

🧬 Non-coding RNAs come in various types and have different structures, performing a multitude of important functions despite not encoding for proteins.
📚 Messenger RNA (mRNA) is a coding RNA that is transcribed from DNA and later translated into proteins.
🧬 Early in the Human Genome Project, it was discovered that a large part of the genome is non-coding, leading to the misconception of 'junk DNA'.
🤔 Contrary to early beliefs, the largest part of the genome is transcribed into non-coding RNAs, which have essential functions.
🔍 Non-coding RNAs can be categorized into housekeeping and regulatory functions, with some roles overlapping between the two.
🔑 Transfer RNA (tRNA) is a housekeeping non-coding RNA that brings specific amino acids to the ribosome during translation.
🌟 Ribosomal RNA (rRNA), together with proteins, forms ribosomal units necessary for the translation process.
⚙️ Small nuclear RNAs (snRNA) and small nucleolar RNAs (snoRNA) are involved in the splicing and chemical modification of other RNA molecules, respectively.
🛡️ RNA interference is a natural mechanism that protects cells from foreign RNA, involving small interfering RNAs (siRNAs) and microRNAs (miRNAs) in gene silencing.
🧬 Piwi-interacting RNAs (piRNAs) are longer non-coding RNAs that guide proteins to target RNA for cleavage, playing a role in gene regulation.
📚 Long non-coding RNAs (lncRNAs) are over 200 nucleotides long and are implicated in gene regulation, with examples like Xist RNA involved in X-chromosome inactivation.
🔬 The multi-functionality of non-coding RNAs, especially their role in human diseases such as cancer, is an area of ongoing research.

Q & A

What are non-coding RNAs and why are they significant?
-Non-coding RNAs (ncRNAs) are RNA molecules that do not encode for proteins. They are significant because they perform a multitude of essential functions within the cell, despite not being translated into proteins.
What is the role of messenger RNA (mRNA) in the context of RNA molecules?
-Messenger RNA (mRNA) is a coding RNA molecule that is produced during the transcription of genetic information from DNA. It is then modified and translated into proteins, making it a crucial component in the process of gene expression.
Why was the term 'junk DNA' initially used in the context of the human genome project?
-The term 'junk DNA' was used because it was initially thought that a large part of the human genome did not code for any proteins. However, it was later discovered that much of this non-coding DNA is transcribed into functional non-coding RNAs.
What is the function of transfer RNA (tRNA) in protein synthesis?
-Transfer RNA (tRNA) plays a housekeeping role in protein synthesis by bringing specific amino acids to the ribosome based on the anticodon, which matches the codon on the mRNA.
How do ribosomal RNAs (rRNAs) contribute to the translation process?
-Ribosomal RNAs (rRNAs), along with protein components, form ribosomal units that are essential for the translation process, facilitating the assembly of amino acids into proteins.
What is the role of small nuclear RNAs (snRNAs) in the cell?
-Small nuclear RNAs (snRNAs), together with various protein subunits, form the spliceosome, an RNA-protein complex that orchestrates the splicing of pre-mRNA, which is crucial for proper gene expression.
How do small nucleolar RNAs (snoRNAs) participate in RNA modification?
-Small nucleolar RNAs (snoRNAs) are involved in guiding chemical modifications of other RNA molecules within a ribonucleoprotein complex, playing a role in the maturation and modification of ribosomal RNAs.
What is RNA interference and how do small interfering RNAs (siRNAs) function in this process?
-RNA interference is a mechanism that protects the cell from foreign RNA, such as viral infections. Small interfering RNAs (siRNAs) are part of this process, being involved in gene silencing and processed by the enzyme Dicer to regulate transcription.
What is the purpose of Piwi-interacting RNAs (piRNAs) in gene regulation?
-Piwi-interacting RNAs (piRNAs) are longer non-coding RNAs that regulate gene expression by silencing transposable elements. They guide Piwi proteins to the target RNA, where the proteins execute cleavage.
What are long non-coding RNAs (lncRNAs) and what is an example of their function?
-Long non-coding RNAs (lncRNAs) are non-coding RNA molecules longer than 200 nucleotides that are involved in diverse functions, including gene regulation. An example is the Xist RNA, which is involved in X-chromosome inactivation in female mammals.
How have long non-coding RNAs been implicated in human diseases?
-Long non-coding RNAs have been implicated in various human diseases, including different types of cancer, due to their regulatory roles in gene expression and potential dysregulation in disease states.

Outlines

00:00

🧬 Non-Coding RNAs: The Silent Workforce

This paragraph introduces the concept of non-coding RNAs (ncRNAs), which, despite not encoding for proteins, perform a variety of crucial functions within the cell. It contrasts coding RNA, like messenger RNA (mRNA), which is translated into proteins, with ncRNAs that have been historically overlooked due to their non-coding nature. The human genome project revealed that only a small fraction of the genome encodes for proteins, leading to the discovery of the significant role of ncRNAs. The paragraph outlines different types of ncRNAs, such as transfer RNA (tRNA), ribosomal RNA (rRNA), small nuclear RNA (snRNA), and small nucleolar RNA (snoRNA), each with specific housekeeping functions in processes like translation and splicing. Additionally, it touches on regulatory roles of ncRNAs, including RNA interference through small interfering RNAs (siRNAs) and microRNAs (miRNAs), which are involved in gene silencing, and piwi interacting RNAs (piRNAs), which guide proteins to silence transposable elements.

05:01

🌟 Long Non-Coding RNAs: The Multifaceted Regulators

The second paragraph delves into long non-coding RNAs (lncRNAs), which are distinguished by their length of over 200 nucleotides. It highlights the diverse functions of lncRNAs in gene regulation and mentions a specific example, the Xist RNA, which plays a key role in X-chromosome inactivation in female mammals. This process ensures that only one of the two X chromosomes is active, balancing the gene expression levels between males and females. The paragraph also connects the regulatory capabilities of lncRNAs to their implications in human diseases, such as various types of cancer. The multi-functionality of these molecules is an ongoing area of research, indicating the depth and complexity of ncRNAs in cellular processes.

Mindmap

Keywords

💡non-coding RNAs

Non-coding RNAs (ncRNAs) are RNA molecules that do not encode for proteins. They play a variety of roles in the cell, including regulation of gene expression and maintenance of cellular functions. In the video, non-coding RNAs are the central theme, emphasizing their importance despite not being translated into proteins, and their diverse functions are explored throughout the script.

💡messenger RNA

Messenger RNA (mRNA) is an RNA molecule that is transcribed from DNA and carries genetic information to be translated into proteins. It is referred to as 'coding RNA' because it encodes for proteins. In the script, mRNA is contrasted with non-coding RNAs to highlight the different roles RNA can have within the cell.

💡human genome project

The Human Genome Project was an international scientific research project aimed at determining the sequence of DNA nucleotides that make up the human genome, as well as identifying and mapping the genes present in the genome. The script mentions this project to illustrate the discovery that a large part of the human genome does not code for proteins, leading to the realization of the importance of non-coding RNAs.

💡transfer RNA

Transfer RNA (tRNA) is a type of non-coding RNA that plays a crucial role in protein synthesis by carrying specific amino acids to the ribosome, where they are assembled into proteins according to the mRNA template. The script highlights tRNA as an essential component of the translation process, with over 31 different tRNA molecules in humans.

💡ribosomal RNA

Ribosomal RNA (rRNA) is a component of ribosomes, the cellular machinery responsible for protein synthesis. rRNA, along with proteins, forms the structure of the ribosome. In the script, rRNA is mentioned as having a housekeeping role, necessary for the translation process.

💡small nuclear RNA

Small nuclear RNAs (snRNAs) are a class of small RNAs that are part of the spliceosome, a large ribonucleoprotein complex responsible for splicing of pre-mRNA. The script describes snRNAs as assembling with protein subunits to orchestrate the splicing process, which is essential for the maturation of mRNA.

💡small nucleolar RNA

Small nucleolar RNAs (snoRNAs) are non-coding RNAs found in the nucleolus of the cell, involved in the chemical modification of other RNA molecules, such as rRNAs. The script explains that snoRNAs function similarly to guide RNAs, playing a role in the maturation and modification of ribosomal RNAs.

💡RNA interference

RNA interference (RNAi) is a biological process in which small RNA molecules, such as small interfering RNAs (siRNAs) and microRNAs (miRNAs), regulate gene expression by silencing specific genes. The script mentions RNAi as a natural mechanism that protects cells from foreign RNA, such as during viral infections, and involves non-coding RNAs in gene regulation.

💡piwi interacting RNA

Piwi interacting RNAs (piRNAs) are a class of small non-coding RNAs involved in silencing transposable elements in the genome. The script describes piRNAs as guiding proteins to target RNAs for cleavage, thereby playing a role in gene regulation and genome stability.

💡long non-coding RNA

Long non-coding RNAs (lncRNAs) are non-coding RNA molecules longer than 200 nucleotides that have diverse functions in the cell, including regulation of gene expression. The script provides an example of lncRNAs, such as Xist RNA, which is involved in X-chromosome inactivation in female mammals, and mentions their implication in human diseases like cancer.

💡gene regulation

Gene regulation refers to the complex processes that cells use to control the structure and function of genes. The script discusses various non-coding RNAs, such as lncRNAs, miRNAs, and piRNAs, that play roles in gene regulation, either by silencing genes or guiding proteins to specific RNA targets.

Highlights

Non-coding RNAs come in various types and have different structures and functions, despite not encoding for proteins.

RNA is commonly associated with messenger RNA, which is produced when genetic information is transcribed and then translated into proteins.

Only a small subset of the human genome encodes for proteins, with the majority being non-coding and previously considered 'junk DNA'.

Non-coding RNAs have been found to possess essential functions, contrary to the early belief that they were 'junk'.

Transfer RNA (tRNA) is an essential component for translation, bringing specific amino acids to the ribosome based on the anticodon.

There are over 31 different tRNA molecules in humans, highlighting the diversity of non-coding RNAs.

Ribosomal RNA (rRNA), along with proteins, forms ribosomal units required for translation, another key housekeeping role of non-coding RNAs.

Small nuclear RNAs (snRNA) assemble with protein subunits to form the spliceosome, which orchestrates RNA splicing.

Small nucleolar RNAs (snoRNA) guide chemical modifications of other RNA molecules in ribonuclear protein complexes.

Non-coding RNAs can interfere with other RNA through RNA interference, a natural mechanism protecting cells from foreign RNA like viral infections.

Small interfering RNAs (siRNAs) and microRNAs (miRNAs) are involved in gene silencing and are processed by the enzyme Dicer.

Piwi interacting RNAs (piRNAs) regulate gene expression by silencing transposable elements and guiding PV proteins to target RNA for cleavage.

Long non-coding RNAs are over 200 nucleotides long and have diverse functions, including gene regulation.

The Xist RNA is an example of a long non-coding RNA involved in X-chromosome inactivation in female mammals.

The regulation by long non-coding RNAs has implications in human diseases such as various types of cancer.

The multi-functionality of non-coding RNAs is an ongoing area of investigation, with many functions still being discovered.