Molecular Mechanisms of the DYRK1A-regulated DNA Repair

Molecular Mechanisms of the DYRK1A-regulated DNA Repair Polina Bukina, Dept. of Biology, with Dr. Sarah Golding, Dept. of Biology The functions of human Dual-specificity tyrosine (Y)-Regulated Kinase 1A, or DYRK1A, include cell cycle control and differentiation. DYRK1A is required for assembly of the DREAM complex and repression of the cell cycle-dependent genes, such as BRCA1 and RAD51, in quiescence. Our lab previously reported that overexpression of DYRK1A inhibits the accumulation of a DNA repair protein 53BP1, at the DNA double-stranded breaks (DSB). Accumulation of 53BP1 is attributed to repair by non-homologous end joining (NHEJ) over homologous recombination (HRR). The function of 53BP1 is opposed by RNF169, a ubiquitin-binding protein that also accumulates at the DSB sites and promotes HRR. It was found that DYRK1A interacts with RNF169 to regulate the displacement of 53BP1 from the DSB sites. This study focuses on RNF169 in order to understand the role of DYRK1A in DNA damage response. We used the Multi-Dimensional Protein Identification Technology (MudPIT) proteomic analysis to identify RNF169-interacting proteins. Human cancer U-2 OS cells stably expressing HA-tagged RNF169, as well as control cells were used for immunoprecipitation. The samples were sent to Stowers Institute for Medical Research for MudPIT proteomic analysis. In order to understand the regulation of DNA repair by DYRK1A, the RNA sequencing dataset was analyzed as part of other studies in the lab. The expression of the mRNA for repair factors RAD51 and BRCA1 was found to be regulated by DYRK1A. To determine the significance of this finding, an experiment was designed to assess BRCA1 and RAD51 protein levels in the normal U-2 OS cells and in the cells lacking DYRK1A (U-2 OS DYRK1A knockout cells) after inducing DNA damage by gamma irradiation. It was found that the levels of RAD51, BRCA1 and 53BP1 levels were increased with DYRK1A KO. These results were consistent with the finding that DNA repair efficiency is increased with DYRK1A KO. Further studies can help to understand if these effects are mediated by DYRK1A-regulated DREAM complex.https://scholarscompass.vcu.edu/uresposters/1357/thumbnail.jp

The Semiotics of Art and Its Abilities to be Used in the Process of Teaching

При финансовой поддержке Российского гуманитарного научного фонда, проект № 08-06-14134

Arts and Educasion in arts: the Problem of Interaction

При финансовой поддержке Российского гуманитарного научного фонда, проект № 07-06-14162

Long-term succession and loss of foundation species in a temperate broadleaved forest in southern Sweden

Dalby Söderskog is an old-growth temperate forest dominated by pedunculate oak (Querus robur), wych elm (Ulmus glabra), European ash (Fraxinus excelsior), and beech (Fagus sylvatica). After being released from a historical management regime of livestock grazing, autogenic succession began in the forest. This allowed for shade tolerant species to prevail. A steady state forest community dominated by elm was affected by Dutch elm disease (DED), while ash dieback negatively impacted on the ash population at the end of the 20th century. In this study, we report on 95 years of secondary succession in Dalby Söderskog with emphasis on the effects of DED and ash dieback on forest compositional dynamics. Additionally, future trends in forest succession were discussed in response to changing environmental conditions. In 2012, an inventory of trees > 10 cm in diameter at breast height was carried out. This was done across 74 systematically distributed plots which were reconstructed from a survey of herb layer vegetation conducted in 2010. The results were compared with similar investigations completed in 1909, 1916, 1935 and 1970. The new inventory data representing species composition and forest structure were analyzed and discussed in relation to DED, ash dieback and oak decline. For each sample tree vitality was also recorded in order to explain compositional dynamics and succession trends. The results show that oak has been retreating from the stand for a long time, while elm is declining in abundance only recently after a period of dominance. Ash has become a dominant species in 2012 due to its ability to regenerate vigorously in gaps created where elms have fallen because of DED. However, a large amount of infected ash were observed in 2012. For beech, increased recruitment was found in Dalby Söderskog during the last sampling period. Despite dramatical changes in compositional dynamics, overall structural dynamics look more stable than species level diameter structure indicates. I conclude that oak will disappear in the long run if no actions are taken in the future, as historically its presence was a result of a wood pasture regime in Dalby Söderskog. DED had a significant impact on the tree species composition and will continue to affect young elm trees, resulting in an understory population with high turnover. Ash and beech will probably increase and maintain a dominant position in the canopy. Although, changes in composional dynamics occured, the forest still proved to be relatively resistant as an ecological system as seen in its consistency pertaining to structural dynamics

Octet Magnetic Moments with Null Instantons and Semibosonized Nambu-Jona-Lasinio Model

It is shown that the difference between the magnetic moment results in the quark model with null instantons and semibosonized Nambu-Jona-Lasinio model lies in the description of the magnetic moment of the $\Lambda$-hyperon.Comment: RevTex, 6 pages, submitted to Progr.Theor.Phy