Discovery of TAK-960: An orally available small molecule inhibitor of polo-like kinase 1 (PLK1)

Using structure-based drug design, we identified and optimized a novel series of pyrimidodiazepinone PLK1 inhibitors resulting in the selection of the development candidate TAK-960. TAK-960 is currently undergoing Phase I evaluation in adult patients with advanced solid malignancies.     

Refugia and geographic barriers of populations of the desert poppy, Hunnemannia fumariifolia (Papaveraceae)

Phylogeographic data and divergence estimation times as well as current and past ecological niche modeling for the Mexican tulip poppy, Hunnemannia fumariifolia Sweet, were combined in order to understand its biogeographic history. Divergence times were estimated to determine if divergence occurred during the Pleistocene. Ecological niche modelling was used to determine if the last glacial maximum (LGM) was responsible for the southward movement of poppy populations into the Tehuacán-Cuicatlán Valley. Analyses were performed to detect any geographical barriers that might have caused genetic discontinuities among populations across the entire range of distribution. Current and Pleistocene ecological niche models were created for H. fumariifolia using eight environmental variables derived from temperature and precipitation. The evidence shows that divergence of the three main clades in H. fumariifolia occurred from the Early Pleistocene to Mid-Miocene. It was also found that gene flow between the populations of H. fumariifolia could have been limited by the LGM, by climate change during the Quaternary, and by the complex topography of the Sierra Madre Oriental and the Trans-Mexican Volcanic Belt. Furthermore, all of these processes may have resulted in the patchy distribution of suitable microhabitats for H. fumariifolia in its geographical range. Ecological niche models constructed using the MIROC3 model indicated that populations did not move to the north but rather that they had suitable ecological habitats in the Chihuahuan Desert, which harbored Pinus-Juniperus forests during that period.     

Discovery of cell-active phenyl-imidazole Pin1 inhibitors by structure-guided fragment evolution

Pin1 is an emerging oncology target strongly implicated in Ras and ErbB2-mediated tumourigenesis. Pin1 isomerizes bonds linking phospho-serine/threonine moieties to proline enabling it to play a key role in proline-directed kinase signalling. Here we report a novel series of Pin1 inhibitors based on a phenyl imidazole acid core that contains sub-μM inhibitors. Compounds have been identified that block prostate cancer cell growth under conditions where Pin1 is essential.     

Identification and characterization of the aspartate chemosensory receptor of Campylobacter jejuni

Campylobacter jejuni is a highly motile bacterium that responds via chemotaxis to environmental stimuli to migrate towards favourable conditions. Previous in silico analysis of the C. jejuni strain NCTC11168 genome sequence identified 10 open reading frames, tlp1‐10, that encode putative chemosensory receptors. We describe the characterization of the role and specificity of the Tlp1 chemoreceptor (Cj1506c). In vitro and in vivo models were used to determine if Tlp1 had a role in host colonization. The tlp1^‐ isogenic mutant was more adherent in cell culture, however, showed reduced colonization ability in chickens. Specific interactions between the purified sensory domain of Tlp1 and l ‐aspartate were identified using an amino acid array and saturation transfer difference nuclear magnetic resonance spectroscopy. Chemotaxis assays showed differences between migration of wild‐type C. jejuni cells and that of a tlp1^‐ isogenic mutant, specifically towards aspartate. Furthermore, using yeast two‐hybrid and three‐hybrid systems for analysis of protein–protein interactions, the cytoplasmic signalling domain of Tlp1 was found to preferentially interact with CheV, rather than the CheW homologue of the chemotaxis signalling pathway; this interaction was confirmed using immune precipitation assays. This is the first identification of an aspartate receptor in bacteria other than Escherichia coli and Salmonella enterica serovar Typhimurium.     

Requirements for polyadenylation at the 3' end of LINE-1 elements

LINE-1 (L1) is the only active, autonomous, non-LTR, human retroelement. There are about 5 × 10⁵ L1 copies in the human genome, the majority of which are truncated at their 5′ ends. Both truncated and full-length L1 insertions contain a polyadenylation (polyA) signal at their 3′ ends. A typical polyA site consists of the three main cis-acting elements: a conserved hexamer, cleavage site, and a GU-rich downstream region. A newly inserted L1 copy contains the conserved AATAAA hexamer at the end of its sequence. However, the GU-rich downstream region has to be provided by the neighboring genomic sequences and therefore it would vary for every L1 copy. Using northern blot analysis of transiently transfected L1 expression vectors we demonstrate that L1 element contain sequence that allow efficient polyadenylation at the L1 3′ end upon retrotransposition into a new genomic location independent of the base composition downstream of the insertion site. The strategy of polyadenylation at the 3′ end of L1 parallels the approach the element employs at its 5′UTR by having an unusual internal polymerase II promoter, making new insertions less dependent on the properties of the flanking sequences at the new locus.     

Hematologic, protein electrophoresis, biochemistry, and cholinesterase values of free-living black stork nestlings (Ciconia nigra)

Hematologic, protein electrophoresis, serum biochemistry, and cholinesterase values were determined in 36 free-living black stork nestlings (Ciconia nigra) between 25 and 53 days of age in order to establish normal reference values for this population. The following values were evaluated: white blood cell counts, red blood cell counts, packed cell volume, hemoglobin, heterophils, lymphocytes, monocytes, eosinophils, prealbumin, albumin, alpha-globulin, beta-globulin, gamma-globulin, total protein, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, creatine kinase, calcium, phosphorus, iron, cholesterol, glucose, triglycerides, uric acid, urea, creatinine, total solids, bile acids, and butyrylcholinesterase. Sex-dependent differences were observed in hemoglobin, prealbumin, albumin, gamma-globulin, total protein, alkaline phosphatase, and triglycerides. Packed cell volume, butyrylcholinesterase, aspartate aminotransferase, creatine kinase, and creatinine increased with age, whereas albumin, mean cell volume, calcium, phosphorus, cholesterol, and total solids decreased with age. These hematologic and serum biochemistry values can be used as reference ranges in free-living black stork nestlings.     

Influence of chromatin and single strand binding proteins on the activity of an archaeal MCM

The mini-chromosome maintenance (MCM) complex is the presumptive replicative helicase in archaea and eukaryotes. In archaea, the MCM is a homo-multimer, in eukaryotes a heterohexamer composed of six related subunits, MCM 2-7. Biochemical studies using naked DNA templates have revealed that archaeal MCMs and a sub-complex of eukaryotic MCM 4, 6 and 7 have 3' to 5' helicase activity. Here, we investigate the influence of the major chromatin proteins, Alba and Sul7d, of Sulfolobus solfataricus (Sso) on the ability of the MCM complex to melt partial duplex DNA substrates. In addition, we test the effect of Sso SSB on MCM activity. We reveal that Alba represents a formidable barrier to MCM activity and further demonstrate that acetylation of Alba alleviates repression of MCM activity.