eIF3a

eIF3a, also known as eukaryotic translation initiation factor 3 subunit A, is a protein that plays a crucial role in the initiation of protein synthesis in eukaryotes. It is a core component of the eukaryotic translation initiation factor 3 (eIF3) complex, which is the largest translation initiation factor and is composed of 13 subunits. The eIF3 complex is essential for assembling the 43S pre-initiation complex and facilitating its binding to the messenger RNA (mRNA).

Specifically, eIF3a is one of the subunits that bind directly to the 40S ribosomal subunit. It contributes to the stability of the eIF3 complex and its interaction with other initiation factors, such as eIF2 and eIF1A. Through these interactions, eIF3a helps to position the 40S ribosomal subunit at the correct start codon on the mRNA, a critical step for initiating translation.

Dysregulation of eIF3a has been implicated in various cellular processes and diseases, including cancer. Its involvement in controlling protein synthesis, a fundamental process for cell growth and proliferation, makes it a subject of interest in cancer research. Alterations in eIF3a expression or activity can affect the translation of specific mRNAs, potentially promoting tumor development and progression. Understanding the precise functions of eIF3a within the eIF3 complex and its role in cellular signaling pathways is an ongoing area of research.