Solving the shugoshin puzzle

Shugoshin proteins form a complex with protein phosphatase 2A (PP2A) that protects centromeric cohesin from separase-mediated cleavage during yeast meiosis I. Recent work shows that this mechanism is conserved from yeast to mammals. Importantly, a model emerges that explains a long-standing puzzle, namely why the shugoshin-PP2A complex mediates protection of centromeric cohesin from separase cleavage specifically during meiosis I, but not during meiosis II or mitosis.     

Pyrrolo-pyrimidones: a novel class of MK2 inhibitors with potent cellular activity

Pyrrolo-pyrimidones of the general structure 1 were synthesized and evaluated for their potential as MK2 inhibitors. Potent derivatives were discovered which inhibit MK2 in the nanomolar range and show potent inhibition of cytokine release from LPS-stimulated monocytes. These derivatives were shown to inhibit phosphorylation of hsp27, a downstream target of MK2 and are modestly selective in a panel of 28 kinases.     

A multiplexed protein microarray for the simultaneous serodiagnosis of human immunodeficiency virus/hepatitis C virus infection and typing of whole blood

All donor blood samples must be tested pretransfusion to determine the donor blood type. Standard testing protocols require that assays be performed for important bloodborne pathogens such as hepatitis C, syphilis, hepatitis B, and human immunodeficiency virus. We have demonstrated proof of the concept that a protein microarray can type whole blood and detect antibody to significant pathogens simultaneously from the same donor blood sample. The data collected demonstrate the ability of the array to accurately type blood samples while also detecting the presence of antibodies against both human immunodeficiency virus and hepatitis C virus. In conclusion, we have successfully developed a platform capable of typing human whole blood samples, while at the same time testing for the presence of antibodies specific for human immunodeficiency virus/hepatitis C virus. The major benefits of this system are its amenability to expansion with additional assays, for example, rhesus typing and syphilis and/or hepatitis B virus detection, and also the adaptability of the assay to higher-throughput analysis, currently 16 individual samples per slide, but readily expandable to a 96-well format.     

Association of Borrelia garinii and B. valaisiana with Songbirds in Slovakia

In Europe, 6 of the 11 genospecies of Borrelia burgdorferi sensu lato are prevalent in questing Ixodes ricinus ticks. In most parts of Central Europe, B. afzelii, B. garinii, and B. valaisiana are the most frequent species, whereas B. burgdorferi sensu stricto, B. bissettii, and B. lusitaniae are rare. Previously, it has been shown that B. afzelii is associated with European rodents. Therefore, the aim of this study was to identify reservoir hosts of B. garinii and B. valaisiana in Slovakia. Songbirds were captured in a woodland near Bratislava and investigated for engorged ticks. Questing I. ricinus ticks were collected in the same region. Both tick pools were analyzed for spirochete infections by PCR, followed by DNA-DNA hybridization and, for a subsample, by nucleotide sequencing. Three of the 17 captured songbird species were infested with spirochete-infected ticks. Spirochetes in ticks that had fed on birds were genotyped as B. garinii and B. valaisiana, whereas questing ticks were infected with B. afzelii, B. garinii, and B. valaisiana. Furthermore, identical ospA alleles of B. garinii were found in ticks that had fed on the birds and in questing ticks. The data show that songbirds are reservoir hosts of B. garinii and B. valaisiana but not of B. afzelii. This and previous studies confirm that B. burgdorferi sensu lato is host associated and that this bacterial species complex contains different ecotypes.     

Xylosandrus germanus in Central Europe: Spread into and within the Czech Republic

Invasive organisms represent great threats to ecosystems and great challenges to forest management. In Europe, the black timber bark beetle (Xylosandrus germanus) is an invasive secondary pest that mostly attacks the logs of felled trees. We showed the invasion history for Europe and using many local surveys, we summarize the current distribution and other available information on X. germanus in the Czech Republic. We report that this species is distributed from the lowlands to the mountains in the Czech Republic; it is widespread in the eastern half of the country, where it is more abundant in the warmer south and southeast areas than in the cooler areas. Most (78%) of the known localities are at elevation below 400 m a.s.l. Although an ice storm greatly increased X. germanus abundance near the border with Austria, its high abundance did not result in damage to standing trees. Presence of X. germanus in the Czech Republic for over 10 years has not led to heavy tree infestation.     

Immunosuppressant FK506: Focusing on neuroprotective effects following brain and spinal cord injury

The secondary damage that follows central nervous system (CNS) injury is a target for neuroprotective agents aimed at tissue and function sparing. FK506, a clinically used immunosuppressant, acts neuroprotectively in rat models of brain and spinal cord injury and ischemia. Evidence of in vivo experimental studies highlights the neuroprotective role of FK506 by its direct impact on various cell populations within the CNS. The participation of FK506 in modulation of post-traumatic inflammatory processes is a further potential aspect involved in CNS neuroprotection. In this review we provide an overview of the current laboratory research focusing on the multiple effects of FK506 on neuroprotection following CNS injury.     

The Rep20 Replication Initiator From the pAG20 Plasmid of Acetobacter aceti

In the previously isolated pAG20 plasmid from the Acetobacter aceti CCM3610 strain, the Rep20 protein was characterized as a main replication initiator. The pAG20 plasmid origin was localized in the vicinity of the rep20 gene and contained two 21-nucleotide-long iteron sequences, two 13-nucleotide-long direct repeats, and a DnaA-binding site. Electrophoretic mobility shift assay and nonradioactive fragment analysis confirmed that the Rep20 protein interacted with two direct repeats (5′-TCCAAATTTGGAT′-3′) and their requirement during plasmid replication was verified by mutagenesis. Although the association could not be validated of the DnaA protein of from the host cells of Escherichia coli with the plasmid-encoded replication initiator that usually occurs during replication initiation, Rep20 was able to form dimeric structures by which it could bind the sequence of the rep20 gene and autoregulate its own expression. Targeted mutagenesis of the Rep20 protein revealed the importance of the third α-helix and ⁶³Lys, specifically during DNA binding. The second, closely adjacent β-sheet also took part in this process in which ⁵²Asn played a significant role.     

Additional minor ecdysteroid components of Leuzea carthamoides

Seventeen additional minor ecdysteroid compounds were isolated and identified from the roots of Leuzea carthamoides (Wild.) DC. Eight of them are new phytoecdysteroids: carthamoleusterone (13) is a new side-chain cyclo-ether with five-membered ring; 14-epi-ponasterone A 22-glucoside (12) is a rare and unusual natural 14 beta-OH epimer; 15-hydroxyponasterone A (11) is also new and rare with its C-15 substituted position, as well as 22-deoxy-28-hydroxymakisterone C (18) possessing secondary hydroxyl in position C-28 and 26-hydroxymakisterone C (20) with hydroxy groups in positions 25 and 26. New are also 1 beta-hydroxymakisterone C (21) and 20,22-acetonides of inokosterone (8) and integristerone A (10). Series of already known ecdysteroids: ecdysone (1), 20-hydroxyecdysone 2- and 3-acetates (3 and 4), turkesterone (6), inokosterone (7), 24-epi-makisterone A (14), and amarasterone A (22) are reported here as new constituents of L. carthamoides. Seven earlier reported Leuzea ecdysteroids: 20-hydroxyecdysone (2), ajugasterone C (5), integristerone A (9), 24(28)-dehydromakisterone A (15), 24(28)-dehydroamarasterone B (16), (24Z)-29-hydroxy-24(28)-dehydromakisterone C (17) and makisterone C (19) are also included because they are now better characterized.     

Control of Shugoshin function during fission-yeast meiosis

Meiosis consists of a single round of DNA replication followed by two consecutive nuclear divisions. During the first division (MI), sister kinetochores must orient toward the same pole to favor reductional segregation. Correct chromosome segregation during the second division (MII) requires the retention of centromeric cohesion until anaphase II. The spindle checkpoint protein Bub1 is essential for both processes in fission yeast . When bub1 is deleted, the Shugoshin protein Sgo1 is not recruited to centromeres, cohesin Rec8 does not persist at centromeres, and sister-chromatid cohesion is lost by the end of MI. Deletion of bub1 also affects kinetochore orientation because sister centromeres can move to opposite spindle poles in approximately 30% of MI divisions. We show here that these two functions are separable within the Bub1 protein. The N terminus of Bub1 is necessary and sufficient for Sgo1 targeting to centromeres and the protection of cohesion, whereas the C-terminal kinase domain acts together with Sgo2, the second fission-yeast Shugoshin protein, to promote sister-kinetochore co-orientation during MI. Additional analyses suggest that the protection of centromeric cohesion does not operate when sister kinetochores attach to opposite spindle poles during MI. Sgo1-mediated protection of centromere cohesion might therefore be regulated by the mode of kinetochore attachment.     

Lampetra (Eudontomyzon) gracilis,a synonym of Eudontomyzon danfordi

Synopsis Evidence is presented which suggests that the nonparasitic lamprey, Lampetra (Eudontomyzon) gracilis Kux, 1965, is conspecific with the parasitic lamprey Eudontomyzon danfordi Regan, 1911. The diagnostic characters of the holotype and of the non-type material of E. gracilis are features found in E. danfordi specimens in their second and final year of adult life, thereby making the former a junior synonym of the latter.