Transcriptomics: Open Access
Open Access

Mechanisms Involved in Gene Expression

Patrick John^{* *}Correspondence: Patrick John, Department of Biotechnology, Aichi Cancer Center, Aichi, Japan, Email:

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Description

Gene expression

The process through which a gene's information is used to produce either RNA molecules that code for proteins or noncoding RNA molecules with other roles is known as gene expression. Gene expression is tightly controlled and significantly changes depending on the environment.

The process of gene expression includes the following steps:

Transcription: The method by which an RNA template is produced from a section of DNA is called transcription. An enzyme called RNA polymerase "reads" the DNA segment and creates an RNA strand that is complementary to the DNA. The uracil base is used in place of every thymine nucleotide in this complementary RNA strand.

MRNA processing: The mature messenger RNA (mRNA), which can be employed for translation, is created by further modification of this initial RNA transcript. In order to leave only the coding regions (exons), the non-coding portions of the transcript (introns) are cut out of the mRNA during splicing [1].

Non-coding RNA maturation: RNA's non-coding regions (ncRNA) are first synthesised as precursors and then go through additional processing. These sections might be translated into pre-ribosomal RNA (pre-rRNA), which is then cut into ribosomal RNA (rRNA).

RNA export: Most of the mature RNA is moved from the nucleus to the cytoplasm. Although certain RNAs have functions in the nucleus, all RNAs involved in protein synthesis are transported into the cytosol through pores in the nucleus [2].

Translation: The information required to code for proteins is contained in the final mRNA. An amino acid-carrying transfer RNA (tRNA) has a binding site per three base pairs on the mRNA. A ribosome then links the amino acids together to form an incomplete protein chain.

Protein folding: Using enzymes referred to as chaperones, the lengthy chain of amino acids folds to create a three-dimensional structure.

Translocation: Translocation is required for secretory proteins from eukaryotes or prokaryotes to reach the secretory pathway. Signal peptides drive newly created proteins to the eukaryotic Sec61 or prokaryotic SecYEG translocation channel. The signal peptide that has been employed makes a significant difference in the effectiveness of protein secretion in eukaryotes [3].

Protein transport: A variety of signalling sequences or (signal peptides) are employed to guide proteins to their intended locations in the cell because many proteins have destinations other than the cytosol. Prokaryotes have low cell compartmentalization; hence this is typically a straightforward process. To ensure that the protein is delivered to the right organelle, eukaryotes have a wide array of targeting mechanisms. Not all proteins stay inside the cell; many are exported, including extracellular matrix proteins, hormones, and digestive enzymes. In eukaryotes, the export pathway is well developed, and translocation to the endoplasmic reticulum, followed by transport via the Golgi apparatus, is the primary mechanism for the export of these proteins [4].

Conclusion

The process through which a gene's information is used to produce either RNA molecules that code for proteins or noncoding RNA molecules with other roles is known as gene expression. An enzyme called RNA polymerase "reads" the DNA segment and creates an RNA strand that is complementary to the DNA. In order to leave only the coding regions (exons), the non-coding portions of the transcript (introns) are cut out of the mRNA during splicing. These sections might be translated into pre-ribosomal RNA (pre-rRNA), which is then cut into ribosomal RNA (rRNA). Although certain RNAs have functions in the nucleus, all RNAs involved in protein synthesis are transported into the cytosol through pores in the nucleus.

References

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4. Ananya M. "Gene Expression Mechanism". News-Medical. 2022.