Est2p

Est2p is a protein found in the yeast Saccharomyces cerevisiae. It is a component of the telomerase enzyme, which is responsible for maintaining telomere length. Telomeres are protective caps at the ends of chromosomes that shorten with each round of cell division. Est2p is the catalytic subunit of telomerase, meaning it possesses the enzymatic activity required to synthesize DNA. This activity is crucial for preventing chromosome end erosion, which can lead to genomic instability and cellular senescence.

The function of Est2p is conserved across many eukaryotic organisms, where it is often referred to by different names, such as TERT (Telomerase Reverse Transcriptase) in humans. The Est2p protein is a reverse transcriptase, meaning it uses an RNA template to synthesize DNA. This RNA template is provided by another telomerase component called Est1p. Together, Est2p and Est1p, along with other associated proteins, form the core telomerase complex.

In yeast, telomere maintenance is essential for the long-term viability of the organism. Est2p plays a critical role in this process, ensuring that telomeres are adequately replicated during DNA synthesis. Mutations or deficiencies in Est2p can lead to progressive telomere shortening, resulting in cell cycle arrest and a phenomenon known as the "Great Wall" in yeast, where cells cease to divide. Research into Est2p and telomerase has significant implications for understanding aging, cancer biology, and the development of potential therapeutic strategies.