Anti-Rif1 antibody - C-terminal

Supplementary info

Activity summary

Rif1 also known as Rap1-interacting factor 1 is a protein that aids in DNA end protection and repair processes. The protein has a molecular mass of approximately 240 kDa and is predominantly expressed in the nucleus of eukaryotic cells. Rif1 interacts directly with telomeric DNA and regulates DNA-double strand break (DSB) repair. Its activity ensures genomic integrity by coordinating access to damaged DNA ends which is essential in the context of maintaining telomere length and chromosomal stability.

Biological function summary

Rif1 plays a central role in the DNA damage response and DNA replication. It operates as part of the shieldin complex which participates in non-homologous end joining (NHEJ) by protecting DNA ends from extensive resection. By doing so Rif1 directs the repair pathway choice towards NHEJ over homologous recombination enabling cell cycle progression in conditions of DNA stress. Its function is particularly significant during the S and G1 phases of the cell cycle during which Rif1 modulates replication timing and forks stalling recovery.

Pathways

Several critical cellular processes involve Rif1 particularly DNA damage repair and cell cycle regulation. Within these pathways Rif1 interacts with proteins such as 53BP1 which is instrumental in controlling pathway selectivity during DNA repair and it influences origin firing through its interplay with replication timing guards. Additionally Rif1 works in conjunction with ATM and ATR kinases which are key regulators in the phosphorylation cascade triggered by DNA damage. These interactions underpin Rif1’s pivotal role in cell cycle checkpoints and repair signaling pathways.

Associated diseases and disorders

Aberrations in Rif1 function have links to cancer and premature aging diseases. Altered Rif1 expression or malfunction can contribute to tumorigenesis especially in cancers where DNA repair pathways are disrupted. This is due in part to its relationship with 53BP1 playing roles in tumor suppression pathways by maintaining genomic stability. Furthermore mutations affecting Rif1 are associated with conditions like Hutchinson-Gilford Progeria Syndrome. This connection to lamin A/C another protein involved in nuclear stability highlights its broader impact on maintaining cellular homeostasis and genome integrity.