Messenger RNA
Messenger RNA (mRNA) is a crucial molecule in the process of gene expression, which involves the synthesis of proteins within cells. It plays a central role in the flow of genetic information from DNA to protein.
Here are the key points about messenger RNA:
Function: mRNA serves as a messenger that carries genetic instructions from the DNA in the cell's nucleus to the ribosomes, which are cellular structures responsible for protein synthesis. It acts as an intermediary between DNA and the proteins it codes for.
Transcription: The process of creating mRNA from DNA is called transcription. During transcription, an enzyme called RNA polymerase reads the DNA sequence of a specific gene and synthesizes a complementary mRNA molecule. The mRNA molecule is complementary to one of the DNA strands and is identical to the other DNA strand, except it uses uracil (U) instead of thymine (T).
Codons: The genetic code, which determines the sequence of amino acids in a protein, is carried in the mRNA in the form of codons. Each codon consists of three nucleotide bases and corresponds to a specific amino acid. For example, the codon AUG codes for the amino acid methionine and also serves as the start codon, initiating protein synthesis.
Translation: Once the mRNA molecule is transcribed, it exits the cell nucleus and enters the cytoplasm, where it encounters ribosomes. During translation, ribosomes read the mRNA's codons and match them to the appropriate transfer RNA (tRNA) molecules carrying the corresponding amino acids. This process results in the synthesis of a protein based on the mRNA's genetic code.
Degradation: mRNA is not a permanent molecule. It has a limited lifespan within the cell and is eventually degraded by cellular enzymes. This controlled degradation ensures that the cell can regulate protein production by adjusting the amount and stability of mRNA.
Types of mRNA: There are different types of mRNA in a cell, including messenger RNA that codes for proteins, as well as non-coding RNAs that have various regulatory functions within the cell, such as microRNAs and long non-coding RNAs.
Role in Genetic Regulation: mRNA is a key player in the regulation of gene expression. Various factors, including transcription factors and regulatory RNA molecules, can influence the transcription and stability of mRNA, thereby controlling the amount of protein produced from a specific gene.
Therapeutic Applications: mRNA has gained attention in recent years for its use in mRNA-based therapies, particularly in the development of vaccines and potential treatments for diseases like cancer and genetic disorders. Synthetic mRNA can be designed to produce specific proteins or antigens, offering a promising approach to medicine.
In summary, messenger RNA is a vital molecule in the central dogma of molecular biology, serving as the intermediary between the genetic information stored in DNA and the proteins that perform essential functions in cells. Understanding mRNA's role and regulation is fundamental to understanding the processes of gene expression and protein synthesis
A primary transcript is the single-stranded ribonucleic acid (RNA) product synthesized by transcription of DNA, and processed to yield various mature RNA products such as mRNAs, tRNAs, and rRNAs. The primary transcripts designated to be mRNAs are modified in preparation for translation. For example, a precursor mRNA (pre-mRNA) is a type of primary transcript that becomes a messenger RNA (mRNA) after processing.
Pre-mRNA is synthesized from a DNA template in the cell nucleus by transcription. Pre-mRNA comprises the bulk of heterogeneous nuclear RNA (hnRNA). Once pre-mRNA has been completely processed, it is termed “mature messenger RNA”, or simply “messenger RNA”. The term hnRNA is often used as a synonym for pre-mRNA, although, in the strict sense, hnRNA may include nuclear RNA transcripts that do not end up as cytoplasmic mRNA.
Messenger RNA (mRNA) is a large family of RNA molecules that convey genetic information from DNA to the ribosome, where they specify the aminoacid sequence of the protein products of gene expression. RNA polymerase transcribes primary transcript mRNA (known as pre-mRNA) into processed, mature mRNA. This mature mRNA is then translated into a polymer of amino acids: a protein, as summarized in the central dogma of molecular biology.
Large family of RNA molecules that convey genetic information from DNA to the ribosome, where they specify the amino acid sequence of the protein products of gene expression. The existence of mRNA was first suggested by Jacques Monod and François Jacob. Following transcription of primary transcript mRNA (known as pre-mRNA) by RNA polymerase, processed, mature mRNA is translated into a polymer of amino acids: a protein, as summarized in the central dogma of molecular biology.
As in DNA, mRNA genetic information is in the sequence of nucleotides, which are arranged into codons consisting of three bases each. Each codon encodes for a specific amino acid, except the stop codons, which terminate protein synthesis. This process of translation of codons into amino acids requires two other types of RNA: Transfer RNA (tRNA), that mediates recognition of the codon and provides the corresponding amino acid, and ribosomal RNA (rRNA), that is the central component of the ribosome's protein-manufacturing machinery.
The identification of single or less genes based on mRNA expression as clinical diagnostic markers for glioblastoma (Glioblastoma) remains a challenge