2. Messenger RNA (mRNA) is a pivotal molecule
in the process of gene expression, playing a
crucial role in the translation of genetic
information from DNA to proteins.
This molecule is essential for the functioning
of cells, as it carries the genetic instructions
from the DNA in the cell's nucleus to the
ribosomes in the cytoplasm where proteins
are synthesized.
INTRODUCTION
3. STRUCTURE OF M-RNA
mRNA is a single-stranded molecule composed of ribonucleotides, which are the building
blocks of RNA.
Ribonucleotides consist of a nitrogenous base (adenine, guanine, cytosine, or uracil), a
ribose sugar, and a phosphate group.
The sequence of these bases determines the genetic code carried by the mRNA molecule
Unlike DNA, which has a double-stranded helical structure, mRNA is typically linear.
4. THE GENETICCODE
The genetic code is a set of rules
that determines how the sequence
of nucleotides in mRNA is translated
into a sequence of amino acids in a
protein.
This translation is facilitated by
molecules called transfer RNA (tRNA)
and ribosomes.
Each set of three nucleotides in
mRNA, known as a codon, codes for
a specific amino acid or serves as a
stop signal during protein synthesis.
5. SYNTHESIS OF M-RNA
mRNA synthesis, also known as
transcription, occurs in the cell's
nucleus.
It is carried out by an enzyme called RNA
polymerase, which binds to the DNA at
specific regions called promoters and
begins synthesizing a complementary
mRNA strand based on the DNA
template.
This process involves the initiation,
elongation, and termination phases,
resulting in the production of a pre-
mRNA molecule.
6. RNA PROCESSING
The pre-mRNA molecule undergoes several modifications before it becomes a mature mRNA
ready for translation.
These modifications include capping, polyadenylation, and splicing.
Capping involves adding a modified guanine nucleotide to the 5' end of the mRNA, which
protects it from degradation and helps in ribosome binding.
Polyadenylation adds a string of adenine nucleotides (poly-A tail) to the 3' end, which also
aids in stability and transport of the mRNA.
Splicing involves removing introns (non-coding regions) and joining exons (coding
regions) to generate a continuous coding sequence
7.
8. REGULATIONOF MRNA
The expression of mRNA is tightly regulated to ensure precise control over gene
expression in cells.
This regulation occurs at multiple levels, including transcriptional regulation, post-
transcriptional modifications, and mRNA stability.
Transcriptional regulation involves factors that control the activity of RNA
polymerase and the accessibility of promoters on DNA.
Post-transcriptional modifications, such as alternative splicing and RNA editing,
can generate different mRNA isoforms with varying functions.
Additionally, the stability of mRNA molecules can be influenced by RNA-binding
proteins and non-coding RNAs
9. FUNCTIONS OF MRNA
The primary function of mRNA is to carry genetic information from DNA to ribosomes for
protein synthesis.
This process, known as translation, involves the decoding of the mRNA sequence by
ribosomes and tRNAs to assemble amino acids into a polypeptide chain.
The resulting protein then undergoes folding, modification, and trafficking to its
functional location within the cell or organism.
10. MRNA INGENE EXPRESSION
mRNA plays a central role in gene
expression, which encompasses the
processes of transcription, mRNA
processing, translation, and post-
translational modifications.
Gene expression is tightly regulated
and influenced by various factors,
including environmental cues, cell
signaling pathways, and epigenetic
modifications.
Dysregulation of mRNA expression can
lead to diseases such as cancer,
neurodegenerative disorders, and
metabolic syndromes.
APPLICATIONS OF MRNA
Recent advancements in mRNA
technology have led to its utilization in
various biomedical applications.
mRNA-based vaccines, for example,
have gained prominence due to their
ability to stimulate immune responses
against infectious diseases and
cancers.
Additionally, mRNA therapeutics are
being explored for treating genetic
disorders, autoimmune conditions, and
other medical conditions by delivering
therapeutic mRNA molecules to target
cells.
