What is the role of DNA Polymerase α in eukaryotic DNA replication?

DNA Polymerase α plays a critical role in the initiation of DNA replication in eukaryotic cells. It is primarily involved in synthesizing the RNA-DNA primer needed to start the replication process. This enzyme adds deoxyribonucleotides to the growing strand of DNA after the RNA primer has been laid down, facilitating the transition to the next phases of replication.

During the initiation phase, DNA Polymerase α works in conjunction with a primase enzyme to create a primer that provides the free 3' hydroxyl group essential for DNA polymerases to begin DNA synthesis. Once the primer is established, DNA Polymerase α synthesizes a short stretch of DNA before a different polymerase, such as DNA Polymerase δ or ε, takes over the replication process for elongating the newly synthesized DNA strands.

In this context, while other polymerases provide proofreading activity or are involved in base repair, DNA Polymerase α is specifically significant for initiating the replication of the DNA, making it indispensable for the proper onset of DNA replication in eukaryotic organisms.