Crystal structure of a thermophilic GrpE protein: insight into thermosensing function for the DnaK chaperone system.

A homodimeric GrpE protein functions as a nucleotide exchange factor of the eubacterium DnaK molecular chaperone system. The co-chaperone GrpE accelerates ADP dissociation from, and promotes ATP binding to, DnaK, which cooperatively facilitates the DnaK chaperone cycle with another co-chaperone, DnaJ. GrpE characteristically undergoes two-step conformational changes in response to elevation of the environmental temperature. In the first transition at heat-shock temperatures, a fully reversible and functionally deficient structural alteration takes place in GrpE, and then the higher temperatures lead to the irreversible dissociation of the GrpE dimer into monomers as the second transition. GrpE is also thought to be a thermosensor of the DnaK system, since it is the only member of the DnaK system that changes its structure reversibly and loses its function at heat-shock temperatures of various organisms. We here report the crystal structure of GrpE from Thermus thermophilus HB8 (GrpE(Tth)) at 3.23 A resolution. The resolved structure is compared with that of GrpE from mesophilic Escherichia coli (GrpE(Eco)), revealing structural similarities, particularly in the DnaK interaction regions, and structural characteristics for the thermal stability of GrpE(Tth). In addition, the structure analysis raised the possibility that the polypeptide chain in the reported GrpE(Eco) structure was misinterpreted. Comparison of these two GrpE structures combined with the results of limited proteolysis experiments provides insight into the protein dynamics of GrpE(Tth) correlated with the shift of temperature, and also suggests that the localized and partial unfolding at the plausible DnaK interaction sites of GrpE(Tth) causes functional deficiency of nucleotide exchange factor in response to the heat shock

Improvement of Translation Accuracy for the Outlines of Japanese Statutes by Splitting Parenthesized Expressions

To globally share Japanese legal information, we translate the Outlines of Japanese statutes. These outlines are the official summaries of Japanese statutes and are useful to quickly understand their contents. In a previous statistical machine translation system for the outlines, we found that the training corpus consisted of both statutes and their outlines, including many long sentences that reduced the translation quality. To solve this problem, we shortened the length of sentences and focused on parenthesized expressions. In this paper, we propose a translation method that splits off parenthesized expressions from the sentences. Experimental result shows the effectiveness of our method

Inverse Problem of Cosmic-Ray Electron/Positron from Dark Matter

We discuss the possibility of solving the inverse problem of the cosmic-ray electron/positron from decaying/annihilating dark matter, and show simple analytic formulae to reconstruct the source spectrum of the electron/positron from the observed flux. We also illustrate our approach by applying the obtained formula to the just released Fermi data as well as the new HESS data.Comment: 16 pages, 6 figure

Decreased serum phosphate levels are a useful biomarker to predict occurrence and severity of cytokine release syndrome in chimeric antigen receptor T-cell therapy

サイトカイン放出症候群の発症と重症化を予見する新たな指標 --キメラ抗原受容体T細胞療法における血清リン値が鍵--. 京都大学プレスリリース. 2022-10-19

The PennState/Toru\'n Center for Astronomy Search for Planets Around Evolved Stars. Basic parameters of a sample of evolved stars

The objective of the PSU/TCfA Search for Planets Around Evolved Stars is to study evolution of planetary systems in the stellar evolution timescale. For such an analysis precise physical parameters of the hosts of the planetary systems are essential. In this paper we present an attempt to obtain basic physical parameters for a sample of evolved stars observed within our survey with the High Resolution Spectrograph of the Hobby-Eberly Telescope.Comment: 2 pages, to appear in "Extreme Solar Systems", 2007 ASP Conference Series, eds. Debra Fischer, Fred Rasio, Steve Thorsett and Alex Wolszcza

Programs for calculating the statistical powers of detecting susceptibility genes in case–control studies based on multistage designs

Motivation: A two-stage association study is the most commonly used method among multistage designs to efficiently identify disease susceptibility genes. Recently, some SNP studies have utilized more than two stages to detect disease genes. However, there are few available programs for calculating statistical powers and positive predictive values (PPVs) of arbitrary n-stage designs

Ocular Changes --Cataract And Retinal Lesion-- In Spontaneously Diabetic Torii (SDT) Fatty Rats, An Obese Type 2 Diabetic Model

Cataract and retinopathy remain the preventable cause of blindness worldwide, and many pharmacological strategies have been proposed for the treatment of these eye diseases. Animal models play an important role in understanding the pathophysiological features of eye disease and developing for a new therapy. In this study, we investigated the development of cataract and retinal lesion with diabetes using an obese type 2 diabetic models SDT fatty rat. Macroscopic analysis in eyes was performed from 16 to 24 weeks of age and histological analysis was performed at 24 weeks of age. As a result, the lens cloudiness was observed from 19 weeks of age and the degree of the cloudiness was more progressed until 24 weeks of age. Histopathological findings, such as degeneration of lens fiber and shortening and irregular arrangement of cone and rod in retinal tissue, were observed at 24 weeks of age. In conclusion, SDT fatty rats may be useful to understand the pathological features in diabetic cataract and retinopathy develop a new therapy for the disease