STN1
Description
The STN1 (STN1 subunit of CST complex) is a protein-coding gene located on chromosome 10.
STN1, also known as Oligonucleotide/oligosaccharide-binding fold-containing protein 1 and Suppressor of cdc thirteen homolog, is a subunit of the CST complex. This complex acts as a specialized replication factor, promoting DNA replication under conditions of replication stress or at natural barriers such as the telomere duplex. The CST complex binds to single-stranded DNA with high affinity in a sequence-independent manner. While the isolated subunits bind DNA with low affinity, the complex itself exhibits high affinity binding. Initially, the CST complex was proposed to protect telomeres from DNA degradation. However, it has been shown to participate in various aspects of telomere replication. The CST complex inhibits telomerase and is involved in telomere length homeostasis. It binds to newly telomerase-synthesized 3' overhangs, terminating telomerase action and interfering with the ACD:POT1 complex's telomerase stimulation activity. The CST complex is also thought to participate in fill-in synthesis of the telomeric C-strand, possibly recruiting and activating DNA polymerase alpha. The CST complex facilitates recovery from many forms of exogenous DNA damage. It seems to be involved in the re-initiation of DNA replication at repaired forks and/or dormant origins. It is required for efficient replication of the duplex region of the telomere. It promotes efficient replication of lagging-strand telomeres. The CST complex promotes general replication start following replication-fork stalling, implicating new origin firing. It may be involved in C-strand fill-in during late S/G2 phase independent of its role in telomere duplex replication.
STN1 is a component of the CST complex, a specialized replication factor that promotes DNA replication under challenging conditions, such as replication stress or at natural barriers like telomeres. The CST complex has a high affinity for single-stranded DNA, independent of its sequence, whereas individual subunits bind to DNA with lower affinity. It plays a role in telomere protection by inhibiting telomerase and contributing to telomere length homeostasis. CST binds to newly synthesized telomere overhangs, terminating telomerase activity and interfering with the ACD:POT1 complex's stimulatory effects on telomerase. It's also implicated in the fill-in synthesis of the telomeric C-strand, possibly recruiting and activating DNA polymerase alpha. Furthermore, CST facilitates recovery from various forms of DNA damage, potentially aiding in the reinitiation of DNA replication at repaired forks or dormant origins. It is essential for efficient replication of the duplex region of telomeres and promotes the replication of lagging-strand telomeres. Additionally, CST promotes general replication initiation following replication-fork stalling, indicating its involvement in the firing of new origins. It might also participate in C-strand fill-in during late S/G2 phase, independent of its role in telomere duplex replication.
STN1 is also known as AAF-44, AAF44, OBFC1, RPA-32, bA541N10.2.
