Telomerase RNA stem terminus element affects template boundary element function, telomere sequence, and shelterin...

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• The stem terminus element (STE) in human telomerase RNA is essential for telomerase activity, but its function remains unclear.
• Telomeres are protective caps at the ends of chromosomes, crucial for genomic stability.

Purpose of the Study:

• To investigate the function of the STE in the telomerase RNA component (TER1) of Schizosaccharomyces pombe.
• To elucidate the mechanism by which STE contributes to telomere maintenance.

Main Methods:

• Analysis of cells expressing a partial loss-of-function TER1 STE allele.
• Sequencing of telomeres in mutant and wild-type cells.
• In vivo binding assays for telomere-associated proteins Pot1 and Taz1.

Main Results:

• Schizosaccharomyces pombe TER1 contains an essential STE for telomere maintenance.
• A partial loss-of-function STE mutation resulted in short, stable telomeres via a recombination-independent pathway.
• Mutant telomeres exhibited altered sequences, explained by reverse transcription into the template boundary element.
• Altered telomeres showed reduced binding of Pot1 and Taz1 proteins.

Conclusions:

• The STE in S. pombe TER1 is critical for maintaining telomere sequence integrity, even when distant from the template region.
• Proper telomere sequence, regulated by STE, is essential for the correct assembly of the shelterin complex.
• This study reveals a novel role for STE in safeguarding telomere structure and function.