Verifying That POT1 Binds to Telomeres

Since the pot1 gene was identified by sequence and deduced to be a gene for a telomere end-binding protein, it was important to verify the gene’s function. Fission yeast with pot1 deletions form very small colonies, indicating cell-division problems. It was also confirmed that DNA from a yeast strain lacking pot1 had lost its telomeric repeat sequences.

The yeast pot1 sequence was used to search a database of human DNA sequences to identify human POT1. In the conserved region of the protein (yellow), human POT1 has 48% similarity to fission yeast, which in turn has 40% similarity to a ciliate sequence.