The maintenance of genomic integrity is crucial for the survival of all organisms. In humans, compromised genomic integrity contributes to genetic disorders, aging and cancers. The task of safeguarding the genome is accomplished by the concerted action of a number of cellular processes, including DNA replication, DNA repair, senescence and apoptosis. Many, if not all, of these processes are reg...

The phosphatidyl inositol 3-kinase-like kinases (PIKKs), ataxia-telangiectasia mutated (ATM) and ATM- and Rad3-related (ATR) regulate parallel damage response signalling pathways. ATM is reported to be activated by DNA double-strand breaks (DSBs), whereas ATR is recruited to single-stranded regions of DNA. Although the two pathways were considered to function independently, recent studies have ...

Cell cycle checkpoints maintain genomic integrity by delaying cell division in the presence of DNA damage or replication problems. A crucial player in this process is the ATR kinase. The rapid localisation of ATR to sites of genotoxic stress and the central role of this kinase in the checkpoint response lead to the suggestion that ATR functions as a sensor of DNA lesions. After activation, ATR ...

To ensure survival in the face of genomic insult, cells have evolved complex mechanisms to respond to DNA damage, termed the DNA damage checkpoint. The serine/threonine kinases ataxia telangiectasia-mutated (ATM) and ATM and Rad3-related (ATR) activate checkpoint signaling by phosphorylating substrate proteins at SQ/TQ motifs. Although some ATM/ATR substrates (Chk1, p53) have been identified, t...

Inverse synthetic aperture radar (ISAR) imaging is an effective method to identify unknown targets regardless of weather and illumination conditions. Research results published regarding this topic have focused mainly on imaging and automatic target recognition (ATR) of single targets. However, targets generally fly in formation, so the applicability of ISAR images to ATR of multiple targets mu...

Three phosphatidylinositol-3-kinase-related protein kinases implement cellular responses to DNA damage. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and ataxia-telangiectasia mutated respond primarily to DNA double-strand breaks (DSBs). Ataxia-telangiectasia and RAD3-related (ATR) signals the accumulation of replication protein A (RPA)-covered single-stranded DNA (ssDNA), which is ...

BACKGROUND The DNA replication checkpoint ensures that mitosis is not initiated before DNA synthesis is completed. Recent studies using Xenopus extracts have demonstrated that activation of the replication checkpoint and phosphorylation of the Chk1 kinase are dependent on RNA primer synthesis by DNA polymerase alpha, and it has been suggested that the ATR kinase-so-called because it is related ...

The objective of this study was to develop and compare the performance of laboratory grade and portable attenuated total reflectance infrared (ATR-IR) spectroscopic approaches in combination with partial least squares regression (PLSR) for the rapid quantification of alpaca serum IgG concentration, and the identification of low IgG (<1000 mg/dL), which is consistent with the diagnosis of failur...

Prenatal exposure to 100 mg/kg atrazine (ATR) delays mammary gland (MG) development in resulting female offspring of Long-Evans rats. To determine if the fetal MG was sensitive to ATR effects during specific periods of development, timed-pregnant dams (n = 8/group/block) were dosed for 3- or 7-gestation day (GD) intervals (GD 13-15, 15-17, 17-19, or 13-19) with 100 mg ATR/kg/day or vehicle (C),...

Human cells must faithfully duplicate billions of base pairs of DNA every cell division cycle. Insufficient precursors, DNA damage, and difficult-to-replicate sequences cause replication fork stalling. Even in the best of circumstances, hundreds of forks may stall during each S phase in a human cell, and the frequency increases in cells exposed to genotoxic or oncogenic stresses. Cells must res...