T.14 Modificación postranscripcional del RNA (títol)

Study Notes

RNA Splicing

Definition: The process of removing introns (non-coding regions) and joining exons (coding regions) to form a mature RNA molecule
Occurs in the nucleus, prior to translation
Involves the spliceosome, a complex of RNA and proteins
Types of splicing:
- Constitutive splicing: Default splicing pattern
- Alternative splicing: Different splicing patterns resulting in multiple isoforms
- Splice variants: Different isoforms due to alternative splicing

RNA Methylation

Definition: The addition of a methyl group (-CH3) to specific nucleotides in RNA
Types of RNA methylation:
- N6-methyladenosine (m6A): The most common form of RNA methylation, involved in splicing, translation, and stability
- 5-methylcytosine (m5C): Involved in RNA stability and translation
- 2'-O-methylation: Involved in RNA stability and translation
Functions:
- Regulates RNA stability and translation
- Involved in RNA splicing and processing
- Plays a role in stem cell maintenance and development

MicroRNA Regulation

Definition: MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by binding to messenger RNA (mRNA)
Mechanism:
- miRNAs bind to the 3' untranslated region (UTR) of mRNA
- Inhibits translation by blocking the ribosome or inducing mRNA degradation
Functions:
- Regulates gene expression in development, cell differentiation, and cell proliferation
- Involved in disease pathogenesis, including cancer and neurological disorders

RNA Degradation

Definition: The process of breaking down RNA molecules into smaller components
Mechanisms:
- Exoribonucleases: Break down RNA from the 3' end
- Endoribonucleases: Break down RNA internally
- RNA-induced silencing complex (RISC): Degrades RNA targeted by miRNAs
Functions:
- Regulates RNA levels and quality control
- Involved in response to stress and cellular defense

RNA Editing

Definition: The process of altering the nucleotide sequence of RNA molecules after transcription
Mechanisms:
- ADAR (adenosine deaminase acting on RNA): Converts adenosine to inosine
- APOBEC (apolipoprotein B mRNA editing enzyme, catalytic polypeptide): Converts cytosine to uracil
Functions:
- Regulates gene expression and RNA function
- Involved in RNA splicing and translation
- Plays a role in immune response and defense against viral infections

Description

Explore the mechanisms of RNA splicing, methylation, microRNA regulation, degradation, and editing, and their roles in gene expression and RNA function. Learn about the different types of RNA modification and their implications for cellular processes.