Kyungpook National University

About: Kyungpook National University is a education organization based out in Daegu, South Korea. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 20497 authors who have published 42107 publications receiving 834608 citations.

Observation of a χc2′ candidate in γγ→DD̄ production at belle

Abstract: We report on a search for new resonant states in the process gamma gamma -> D (D) over bar. A candidate C-even charmonium state is observed in the vicinity of 3.93 GeV/c(2). The production rate and the angular distribution in the gamma gamma center-of-mass frame suggest that this state is the previously unobserved chi(')(c2), the 2(3)P(2) charmonium state.

Control of plant germline proliferation by SCF FBL17 degradation of cell cycle inhibitors

Abstract: Double fertilization is a biologically unique reproduction system considered a key innovation in the evolution of flowering plants. Unlike fertilization in animals, double fertilization involves the production of a pair of sperm cells by the selective division of unequal daughter cells. Now a novel F-box protein, FBL17, has been found to promote twin sperm cell production in Arabidopsis. FBL17 targets KRP7, an inhibitor of cyclin-dependent kinases, in the male germ cells. The cell cycle regulation mechanism used by flowering plants is evolutionarily conserved between yeast and animal cells, and this new work shows how regulatory mechanisms have evolved to tailor it to special circumstances. A newly discovered F-box protein of Arabidopsis thaliana that promotes twin sperm cell production is identified. The protein, FBL17, targets KRP7, an Arabidopsis inhibitor of CDKA1, for proteasome-dependent degradation, allowing germ cell division and twin sperm cell production. Flowering plants possess a unique reproductive strategy, involving double fertilization by twin sperm cells1. Unlike animal germ lines, the male germ cell lineage in plants only forms after meiosis and involves asymmetric division of haploid microspores, to produce a large, non-germline vegetative cell and a germ cell that undergoes one further division to produce the twin sperm cells2. Although this switch in cell cycle control is critical for sperm cell production and delivery, the underlying molecular mechanisms are unknown. Here we identify a novel F-box protein of Arabidopsis thaliana, designated FBL17 (F-box-like 17), that enables this switch by targeting the degradation of cyclin-dependent kinase A;1 inhibitors specifically in male germ cells. We show that FBL17 is transiently expressed in the male germ line after asymmetric division and forms an SKP1–Cullin1–F-box protein (SCF) E3 ubiquitin ligase complex (SCFFBL17) that targets the cyclin-dependent kinase inhibitors KRP6 and KRP7 for proteasome-dependent degradation. Accordingly, the loss of FBL17 function leads to the stabilization of KRP6 and inhibition of germ cell cycle progression. Our results identify SCFFBL17 as an essential male germ cell proliferation complex that promotes twin sperm cell production and double fertilization in flowering plants.

Oxidative Stress and Insulin Resistance: The Coronary Artery Risk Development in Young Adults study

Abstract: OBJECTIVE Although cumulative evidence suggests that increased oxidative stress may lead to insulin resistance in vivo or in vitro, community-based studies are scarce. This study examined the longitudinal relationships of oxidative stress biomarkers with the development of insulin resistance and whether these relationships were independent of obesity in nondiabetic young adults. RESEARCH DESIGN AND METHODS Biomarkers of oxidative stress (F2-isoprostanes [F2Isop] and oxidized LDL [oxLDL]), insulin resistance (the homeostasis model assessment of insulin resistance [HOMA-IR]), and various fatness measures (BMI, waist circumference, and estimated percent fat) were obtained in a population-based observational study (Coronary Artery Risk Development in Young Adults) and its ancillary study (Young Adult Longitudinal Trends in Antioxidants) during 2000–2006. RESULTS There were substantial increases in estimated mean HOMA-IR over time. OxLDL and F2Isop showed little association with each other. Mean evolving HOMA-IR increased with increasing levels of oxidative stress markers (P CONCLUSIONS We observed positive associations between each of two oxidative stress markers and insulin resistance. The association with oxidized LDL was independent of obesity, but that with F2Isop was not.