Types of Elongation Factors
There are mainly two types of elongation factors involved in the elongation step of translation:
EF-Tu (in prokaryotes) or
eEF1A (in eukaryotes), and
EF-G (in prokaryotes) or
eEF2 (in eukaryotes).
EF-Tu/eEF1A: These factors bind to aminoacyl-tRNA and GTP, ensuring the correct tRNA is delivered to the ribosome.
EF-G/eEF2: These factors are responsible for the translocation of the ribosome along the mRNA after the peptide bond is formed.
EF-Tu/eEF1A binds to aminoacyl-tRNA and GTP, guiding the tRNA to the ribosome's A-site.
Upon correct codon-anticodon matching, GTP is hydrolyzed, and EF-Tu/eEF1A is released.
Peptide bond formation occurs, transferring the growing peptide to the tRNA in the A-site.
EF-G/eEF2 binds to the ribosome, causing translocation of the ribosome along the mRNA.
The A-site becomes available for the next aminoacyl-tRNA, and the cycle repeats.
Importance in Histology
In histology, understanding the role of elongation factors is crucial for several reasons. They are integral to the synthesis of
proteins, which are vital for the structure and function of
cells and tissues. Disruptions in elongation factor function can lead to
diseases such as
cancer and
neurodegenerative disorders.
Clinical Relevance
Mutations or dysregulation in elongation factors have been linked to various diseases. For example: Cancer: Overexpression of eEF1A has been observed in multiple types of cancer, making it a potential
therapeutic target.
Neurodegenerative Diseases: Abnormalities in eEF2 phosphorylation have been associated with
Alzheimer's disease.
Research and Future Directions
Current research is focusing on the detailed mechanisms of elongation factors and their potential as
biomarkers for disease. Scientists are also exploring
inhibitors of elongation factors as possible treatments for cancer and other diseases.
