Failure to repair endogenous DNA damage in β-cells causes adult-onset diabetes in mice.

Age is the greatest risk factor for the development of type 2 diabetes mellitus (T2DM). Age-related decline in organ function is attributed to the accumulation of stochastic damage, including damage to the nuclear genome. Islets of T2DM patients display increased levels of DNA damage.

Low Affinity DnaA-ATP Recognition Sites in Make Non-equivalent and Growth Rate-Dependent Contributions to the Regulated Timing of Chromosome Replication.

Although the mechanisms that precisely time initiation of chromosome replication in bacteria remain unclear, most clock models are based on accumulation of the active initiator protein, DnaA-ATP. During each cell division cycle, sufficient DnaA-ATP must become available to interact with a distinct set of low affinity recognition sites in the unique chromosomal replication origin, , and assemble the pre-replicative complex (orisome) that unwinds origin DNA and helps load the replicative helicase. The low affinity -DnaA-ATP interactions are required for the orisome's mechanical functions, and may also play a role in timing of new rounds of DNA synthesis.

Origin recognition is the predominant role for DnaA-ATP in initiation of chromosome replication.

In all cells, initiation of chromosome replication depends on the activity of AAA+ initiator proteins that form complexes with replication origin DNA. In bacteria, the conserved, adenosine triphosphate (ATP)-regulated initiator protein, DnaA, forms a complex with the origin, oriC, that mediates DNA strand separation and recruitment of replication machinery. Complex assembly and origin activation requires DnaA-ATP, which differs from DnaA-ADP in its ability to cooperatively bind specific low affinity sites and also to oligomerize into helical filaments.

Spontaneous DNA damage to the nuclear genome promotes senescence, redox imbalance and aging.

Accumulation of senescent cells over time contributes to aging and age-related diseases. However, what drives senescence in vivo is not clear. Here we used a genetic approach to determine if spontaneous nuclear DNA damage is sufficient to initiate senescence in mammals.

Safety and Outcome Measures of First-in-Human Intraperitoneal α Radioimmunotherapy With 212Pb-TCMC-Trastuzumab.

Purpose: One-year monitoring of patients receiving intraperitoneal (IP) Pb-TCMC-trastuzumab to provide long-term safety and outcome data. A secondary objective was to study 7 tumor markers for correlation with outcome.

Methods: Eighteen patients with relapsed intra-abdominal human epidermal growth factor receptor-2 expressing peritoneal metastases were treated with a single IP infusion of Pb-TCMC-trastuzumab, delivered <4 h after 4 mg/kg IV trastuzumab.

Building the bacterial orisome: high-affinity DnaA recognition plays a role in setting the conformation of oriC DNA.

During assembly of the E. coli pre-replicative complex (pre-RC), initiator DnaA oligomers are nucleated from three widely separated high-affinity DnaA recognition sites in oriC. Oligomer assembly is then guided by low-affinity DnaA recognition sites, but is also regulated by a switch-like conformational change in oriC mediated by sequential binding of two DNA bending proteins, Fis and IHF, serving as inhibitor and activator respectively.

DNA damage triggers a chronic autoinflammatory response, leading to fat depletion in NER progeria.

Lipodystrophies represent a group of heterogeneous disorders characterized by loss of fat tissue. However, the underlying mechanisms remain poorly understood. Using mice carrying an ERCC1-XPF DNA repair defect systematically or in adipocytes, we show that DNA damage signaling triggers a chronic autoinflammatory response leading to fat depletion.

Two oppositely oriented arrays of low-affinity recognition sites in oriC guide progressive binding of DnaA during Escherichia coli pre-RC assembly.

The onset of chromosomal DNA replication requires highly precise and reproducible interactions between initiator proteins and replication origins to assemble a pre-replicative complex (pre-RC) that unwinds the DNA duplex. In bacteria, initiator protein DnaA, bound to specific high- and low-affinity recognition sites within the unique oriC locus, comprises the pre-RC, but how complex assembly is choreographed to ensure precise initiation timing during the cell cycle is not well understood. In this study, we present evidence that higher-order DnaA structures are formed at oriC when DnaA monomers are closely positioned on the same face of the DNA helix by interaction with two oppositely oriented essential arrays of closely spaced low-affinity DnaA binding sites.

Remodeling of nucleoprotein complexes is independent of the nucleotide state of a mutant AAA+ protein.

DnaA protein, a member of the AAA+ (ATPase associated with various cellular activities) family, initiates DNA synthesis at the chromosomal origin of replication (oriC) and regulates the transcription of several genes, including its own. The assembly of DnaA complexes at chromosomal recognition sequences is affected by the tight binding of ATP or ADP by DnaA. DnaA with a point mutation in its membrane-binding amphipathic helix, DnaA(L366K), previously described for its ability to support growth in cells with altered phospholipid content, has biochemical characteristics similar to those of the wild-type protein.

Bacterial origin recognition complexes direct assembly of higher-order DnaA oligomeric structures.

Eukaryotic initiator proteins form origin recognition complexes (ORCs) that bind to replication origins during most of the cell cycle and direct assembly of prereplication complexes (pre-RCs) before the onset of S phase. In the eubacterium Escherichia coli, there is a temporally similar nucleoprotein complex comprising the initiator protein DnaA bound to three high-affinity recognition sites in the unique origin of replication, oriC. At the time of initiation, this high-affinity DnaA-oriC complex (the bacterial ORC) accumulates additional DnaA that interacts with lower-affinity sites in oriC, forming a pre-RC.