Tpz1-Ccq1 and Tpz1-Poz1 interactions within fission yeast shelterin modulate Ccq1 Thr93 phosphorylation and telomerase recruitment.

In both fission yeast and humans, the shelterin complex plays central roles in regulation of telomerase recruitment, protection of telomeres against DNA damage response factors, and formation of heterochromatin at telomeres. While shelterin is essential for limiting activation of the DNA damage checkpoint kinases ATR and ATM at telomeres, these kinases are required for stable maintenance of telomeres. In fission yeast, Rad3ATR and Tel1ATM kinases are redundantly required for telomerase recruitment, since Rad3ATR/Tel1ATM-dependent phosphorylation of the shelterin subunit Ccq1 at Thr93 promotes interaction between Ccq1 and the telomerase subunit Est1. However, it remained unclear how protein-protein interactions within the shelterin complex (consisting of Taz1, Rap1, Poz1, Tpz1, Pot1 and Ccq1) contribute to the regulation of Ccq1 Thr93 phosphorylation and telomerase recruitment. In this study, we identify domains and amino acid residues that are critical for mediating Tpz1-Ccq1 and Tpz1-Poz1 interaction within the fission yeast shelterin complex. Using separation of function Tpz1 mutants that maintain Tpz1-Pot1 interaction but specifically disrupt either Tpz1-Ccq1 or Tpz1-Poz1 interaction, we then establish that Tpz1-Ccq1 interaction promotes Ccq1 Thr93 phosphorylation, telomerase recruitment, checkpoint inhibition and telomeric heterochromatin formation. Furthermore, we demonstrate that Tpz1-Poz1 interaction promotes telomere association of Poz1, and loss of Poz1 from telomeres leads to increases in Ccq1 Thr93 phosphorylation and telomerase recruitment, and telomeric heterochromatin formation defect. In addition, our studies establish that Tpz1-Poz1 and Tpz1-Ccq1 interactions redundantly fulfill the essential telomere protection function of the shelterin complex, since simultaneous loss of both interactions caused immediate loss of cell viability for the majority of cells and generation of survivors with circular chromosomes. Based on these findings, we suggest that the negative regulatory function of Tpz1-Poz1 interaction works upstream of Rad3ATR kinase, while Tpz1-Ccq1 interaction works downstream of Rad3ATR kinase to facilitate Ccq1 Thr93 phosphorylation and telomerase recruitment.

SUMOylation regulates telomere length by targeting the shelterin subunit Tpz1(Tpp1) to modulate shelterin-Stn1 interaction in fission yeast.

Telomeres protect DNA ends of linear eukaryotic chromosomes from degradation and fusion, and ensure complete replication of the terminal DNA through recruitment of telomerase. The regulation of telomerase is a critical area of telomere research and includes cis regulation by the shelterin complex in mammals and fission yeast. We have identified a key component of this regulatory pathway as the SUMOylation [the covalent attachment of a small ubiquitin-like modifier (SUMO) to target proteins] of a shelterin subunit in fission yeast. SUMOylation is known to be involved in the negative regulation of telomere extension by telomerase; however, how SUMOylation limits the action of telomerase was unknown until now. We show that SUMOylation of the shelterin subunit TPP1 homolog in Schizosaccharomyces pombe (Tpz1) on lysine 242 is important for telomere length homeostasis. Furthermore, we establish that Tpz1 SUMOylation prevents telomerase accumulation at telomeres by promoting recruitment of Stn1-Ten1 to telomeres. Our findings provide major mechanistic insights into how the SUMOylation pathway collaborates with shelterin and Stn1-Ten1 complexes to regulate telomere length.

Substance use in the emergency department: Screening for risky drug use, using the ASSIST-Lite.

INTRODUCTION: Substance use is a common contributing factor to emergency department (ED) presentations. While screening, brief intervention, and referral to treatment for alcohol and tobacco is common in ED settings, it is not routinely conducted for illicit substances. This study aimed to deploy the ASSIST-Lite to screen for risky use of alcohol and other drugs in the ED, to identify differences in risk based on between demographic characteristics. METHOD: All ED attenders, aged 18 years or older, deemed well enough to participate were approached. Recruitment occurred at the Royal Adelaide Hospital ED between May and June 2017. Participants were asked to self-complete the ASSIST-Lite in the ED waiting room. Overall, 632 people were approached, of which 479 (75.8%) agreed to participate. RESULTS: Alcohol (72.2%), tobacco (27.1%) and cannabis (15.2%) were most commonly reported. Eighty-nine participants reported moderate- or high-risk use of two substances, and a further 49 individuals reported moderate- or high-risk use of three or more substances. Across most substances, age, gender and employment status was associated with risky substance use, with higher likelihood of risk reported by males, unemployed and younger participants. Unemployment was also significantly associated with increased risk severity for both moderate and high-risk illicit use. DISCUSSIONS AND CONCLUSIONS: The rate of risky illicit and polysubstance use found here highlight the need more focused research in ED settings. The findings also provide support for more routine screening, and early intervention approaches; and suggest the need for active referral pathways through an alcohol and other drug consultation liaison service.

Peptide mass fingerprinting of preserved collagen in archaeological fish bones for the identification of flatfish in European waters.

Bones of Pleuronectiformes (flatfish) are often not identified to species due to the lack of diagnostic features on bones that allow adequate distinction between taxa. This hinders in-depth understanding of archaeological fish assemblages and particularly flatfish fisheries throughout history. This is especially true for the North Sea region, where several commercially significant species have been exploited for centuries, yet their archaeological remains continue to be understudied. In this research, eight peptide biomarkers for 18 different species of Pleuronectiformes from European waters are described using MALDI-TOF MS and liquid chromatography tandem mass spectrometry data obtained from modern reference specimens. Bone samples (n = 202) from three archaeological sites in the UK and France dating to the medieval period (ca seventh-sixteenth century CE) were analysed using zooarchaeology by mass spectrometry (ZooMS). Of the 201 that produced good quality spectra, 196 were identified as flatfish species, revealing a switch in targeted species through time and indicating that ZooMS offers a more reliable and informative approach for species identification than osteological methods alone. We recommend this approach for future studies of archaeological flatfish remains as the precise species uncovered from a site can tell much about the origin of the fish, where people fished and whether they traded between regions.

Acceptability and suitability of alcohol, smoking and substance involvement screening test for older people in the community.

Background: Alcohol use is a common phenomenon within Australian culture. While there has been significant focus on alcohol use among young Australians, there has been little on health promotion or early interventions focussing on older Australians.Methods: This paper presents the findings of an explorative study that used four interactive focus group workshops to ask the question: Is an existing World Health Organisation alcohol and drug screening tool called the Alcohol, Smoking and Substance Involvement Screening Test (originally developed for young people) acceptable and suitable for older people? The data were analysed based on the question using thematic coding.Results: Participants generally considered that they would be more comfortable talking with their health providers about their alcohol and drug use rather than filling out the Alcohol, Smoking and Substance Involvement Screening Test themselves. This suggests that the tool should be modified to accommodate the differences in health status that reflect life events of the different older age groups.Conclusion: Due to potential complex medical and diverse range of pharmacotherapies common among this age group, it is recommended that, if the tool is used, it be administered by health practitioners such as nurses.

Stable isotope evidence for late medieval (14th-15th C) origins of the eastern Baltic cod (Gadus morhua) fishery.

Although recent historical ecology studies have extended quantitative knowledge of eastern Baltic cod (Gadus morhua) exploitation back as far as the 16th century, the historical origin of the modern fishery remains obscure. Widespread archaeological evidence for cod consumption around the eastern Baltic littoral emerges around the 13th century, three centuries before systematic documentation, but it is not clear whether this represents (1) development of a substantial eastern Baltic cod fishery, or (2) large-scale importation of preserved cod from elsewhere. To distinguish between these hypotheses we use stable carbon and nitrogen isotope analysis to determine likely catch regions of 74 cod vertebrae and cleithra from 19 Baltic archaeological sites dated from the 8th to the 16th centuries. δ(13)C and δ(15)N signatures for six possible catch regions were established using a larger sample of archaeological cod cranial bones (n = 249). The data strongly support the second hypothesis, revealing widespread importation of cod during the 13th to 14th centuries, most of it probably from Arctic Norway. By the 15th century, however, eastern Baltic cod dominate within our sample, indicating the development of a substantial late medieval fishery. Potential human impact on cod stocks in the eastern Baltic must thus be taken into account for at least the last 600 years.