Eukaryotic elongation factor 1 alpha 1, or eEF1A1, is a protein found in nearly all eukaryotic cells, which are cells that possess a nucleus. It plays a broad role in maintaining cellular health and proper functioning due to its widespread presence and multiple functions.
The Core Function of eEF1A1
eEF1A1’s primary role lies within protein synthesis, specifically during the elongation phase of translation. Protein synthesis is the intricate process by which cells construct proteins based on genetic instructions carried by messenger RNA (mRNA).
During elongation, eEF1A1 acts as a delivery system, binding to molecules called aminoacyl-tRNAs. Each aminoacyl-tRNA carries a specific amino acid, which is a building block of proteins. eEF1A1, in a process dependent on guanosine triphosphate (GTP), escorts these aminoacyl-tRNAs to the A-site of the ribosome, the cellular machinery responsible for protein assembly.
Once the aminoacyl-tRNA is positioned at the ribosome’s A-site, base pairing occurs between the mRNA codon and the tRNA anticodon. This successful pairing triggers the hydrolysis of GTP, leading to the release of the aminoacyl-tRNA from eEF1A1 and its subsequent incorporation into the growing protein chain. This continuous and accurate delivery of amino acids by eEF1A1 is necessary for the production of all cellular proteins.
Diverse Roles Beyond Protein Synthesis
Beyond its primary role in protein synthesis, eEF1A1 exhibits a range of diverse functions within the cell. One such role involves its participation in cytoskeleton organization, the network of protein filaments and tubules in the cytoplasm of many living cells. eEF1A1 can bind to actin, a protein that forms filaments, and contributes to the bundling of these actin filaments, thus influencing cell shape and movement.
eEF1A1 also influences programmed cell death, or apoptosis. It can regulate cell growth and the immune response, and its involvement in cell signaling pathways allows it to modulate various cellular activities. For instance, eEF1A1 interacts with the HDM2 gene product, a protein involved in regulating the tumor suppressor protein p53.
The protein also plays a part in viral replication, where diverse viruses, including human immunodeficiency virus type 1, West Nile virus, and dengue virus, utilize eEF1A1 as a cofactor. It can facilitate the assembly of viral replication complexes and enhance the replication of certain viruses.
eEF1A1 and Human Health
Dysfunction or altered levels of eEF1A1 are connected to various human health conditions. In the context of cancer, eEF1A1 can act as an oncogene or, in some cases, function as a tumor suppressor. Its overexpression has been observed in several human tumors, including breast, ovarian, and lung cancers.
In acute T lymphocytic leukemia, reducing eEF1A1 levels has been shown to inhibit cell proliferation and induce programmed cell death in Jurkat cells, possibly by downregulating specific signaling pathways. Conversely, in colon adenocarcinoma, high eEF1A1 expression has been linked to a favorable prognosis and longer survival rates. These findings suggest eEF1A1 could be a target for new cancer therapies, either by inhibiting its activity where it promotes tumor growth or by enhancing it where it acts as a tumor suppressor.
eEF1A1 also has implications in neurological disorders, including neurodegeneration and developmental conditions. For example, eEF1A1 expression is reduced in the hippocampus of patients with Alzheimer’s disease. In Parkinson’s disease, eEF1A1 influences the expression of genes associated with neuroinflammation.