Mechanisms of Protein Synthesis Regulation in Eukaryotic Cells https://microbiologynote.com/mechanisms-of-protein-synthesis-regulation-in-eukaryotes-cells/

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2. • Protein synthesis regulation refers to the mechanisms by which cells
control the production of proteins.
• Protein synthesis is crucial for cellular processes, and its regulation
ensures the right proteins are produced at the right time and in the right
amounts.
• Regulation occurs at multiple levels: transcriptional, post-
transcriptional, translational, and post-translational.

3. • Controls mRNA synthesis by transcription factors and regulatory
proteins that enhance or repress gene transcription.
• Influences the amount of mRNA produced, thereby affecting protein
synthesis.
Levels of
Regulation

4. • Modifies and processes mRNA molecules before translation.
• Includes steps like the addition of a 5' cap and a poly(A) tail, as well as
splicing.
• Regulatory elements (RNA-binding proteins and non-coding RNAs)
interact with mRNA, influencing stability, localization, and translational
efficiency.
Levels of
Regulation

5. • Controls the efficiency and rate of translation.
• Involves initiation factors, ribosomes, and regulatory proteins.
• Specific proteins or non-coding RNAs can promote or inhibit translation,
allowing selective protein synthesis.
Levels of
Regulation

6. • Modifies proteins after synthesis, affecting their stability, activity,
localization, and interactions.
• Includes phosphorylation, acetylation, glycosylation, and proteolytic
cleavage, among others.
• Plays critical roles in cellular signaling and regulation.
Levels of
Regulation

7. • Initiation: Small ribosomal subunit binds to mRNA at the 5' cap. Initiator
tRNA binds to the start codon, and the ribosome assembles.
• Elongation: Ribosome moves along mRNA, adding amino acids to the
growing polypeptide chain. Involves codon recognition, peptide bond
formation, and translocation.
• Termination: Ribosome reaches a stop codon, release factors bind, and
the polypeptide chain is released.
• Post-translational Modifications: Newly synthesized polypeptide
undergoes modifications for proper structure and function.

8. • Gene loss or partial loss allows cells to specialize.
• Gene amplification increases the number of copies of a gene.
• DNA segment movement and rearrangement result in altered gene expression.
• DNA base modifications, like methylation, can inhibit gene transcription.
Regulation of Translation in Eukaryotes

9. • Histone-mediated regulation: Histones control DNA accessibility through acetylation
and deacetylation.
• Heterochromatin and euchromatin: Determine transcriptional activity based on
chromatin compaction.
• Positive regulation: Inducers bind to protein receptors, activating transcription.
• Alternative promoters: Allow the production of different transcripts and protein
isoforms.
Regulation of Translation in Eukaryotes

10. • Nucleosome displacement and ATP-driven chromatin remodeling complexes alter
chromatin structure.
• Histone acetylase activity neutralizes positive charges on histones, promoting open
chromatin.
• Chromatin remodeling facilitates transcription factor binding and transcriptional
activation.
Regulation of Translation in Eukaryotes

11. • Capping, polyadenylation, and splicing influence amino acid sequence or protein
quantity.
• mRNA degradation controls stability through nucleases.
• RNA editing alters mRNA bases, resulting in modified protein sequences.
• Small RNA molecules (miRNAs and siRNAs) downregulate mRNA translation.
Regulation of Translation in Eukaryotes

12. • Regulation during initiation or elongation phases affects the rate of protein synthesis.
• Factors and signals modulate initiation and elongation reactions.
• Regulation ensures efficient and selective protein synthesis.
Regulation of Translation in Eukaryotes

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