CTC1 : CST telomere replication complex component 1
Description
The CTC1 (CST telomere replication complex component 1) is a protein-coding gene located on chromosome 17.
The CTC1 gene provides instructions for making a protein that plays a critical role in telomeres, which are located at the ends of chromosomes. Telomeres are short, repetitive DNA segments that protect chromosomes from sticking together or breaking down. As cells divide, telomeres progressively shorten. When they become too short, they trigger cell division arrest or self-destruction (apoptosis). The CTC1 protein is part of a group of proteins called the CST complex, which is involved in maintaining telomeres. This complex is essential for copying telomeres to prevent them from becoming too short during cell division. Studies suggest that CTC1 may also have roles in DNA replication unrelated to telomeres, but these functions are not fully understood.
The CST complex, of which CTC1 is a component, is proposed to act as a specialized replication factor that aids in DNA replication under conditions of stress or at natural barriers such as telomeres. It binds strongly to single-stranded DNA in a sequence-independent way, whereas individual subunits have low DNA affinity. The CST complex was initially thought to protect telomeres from degradation. However, it has since been shown to play a role in several aspects of telomere replication. It inhibits telomerase and regulates telomere length, possibly by binding to newly synthesized 3' overhangs and stopping telomerase activity. This might involve its interaction with the ACD:POT1 complex, which interferes with telomerase stimulation. The CST complex may also be involved in filling the telomeric C-strand, likely through recruiting and activating DNA polymerase alpha. It promotes recovery from various forms of DNA damage, potentially by re-initiating replication at repaired forks or dormant origins. The CST complex contributes to telomere maintenance and genome stability. It may participate in telomeric C-strand filling during the late S/G2 phase.
CTC1 is also known as AAF-132, AAF132, C17orf68, CRMCC, tmp494178.
Associated Diseases
- Cerebroretinal microangiopathy with calcifications and cysts 1
- Dyskeratosis congenita
- Coats plus syndrome
