Desensitization of signaling by oncostatin M in human vascular cells involves cytoplasmic Tyr residue 759 in gp130 but is not mediated by either Src homology 2 domain-containing tyrosine phosphatase 2 or suppressor of cytokine signaling 3

Oncostatin M (OnM) signals through cell surface receptors, which utilize the gp130 subunit. In cultured human umbilical vein endothelial cells (HUVEC), OnM transiently elevates mRNA encoding for suppressor of cytokine signaling-3 (SOCS-3). By 1 h of OnM treatment, HUVEC become refractory to the restimulation by OnM, measured as failure to reinduce SOCS-3 mRNA. OnM-induced desensitization also prevents responses to other gp130-signaling cytokines (e.g. leukemia inhibitory factor and interleukin 11). OnM treatment does not affect gp130 expression levels and desensitizes signaling mediated by a transduced chimeric receptor containing extracellular domains of platelet-derived growth factor receptor-beta (PDGFRbeta) and the cytoplasmic region of gp130. Interestingly, a chimeric PDGFRbeta-gp130 mutant receptor, in which intracellular Tyr residue 759 of gp130 is replaced by a Phe residue, mediates prolonged signaling and is not cross-desensitized by OnM. Phospho-Tyr759 is the binding site for both SOCS-3 and for Src homology domain 2-containing tyrosine phosphatase 2 (SHP-2). In human aortic smooth muscle cells, neither prevention of SOCS-3 protein induction, using STAT3 or SOCS-3 antisense, nor prevention of SHP-2 expression, also with antisense, ablates desensitization. These data suggest that desensitization of vascular cells to OnM is mediated in trans and involves Tyr residue 759 in gp130 but is not mediated by either SOCS-3 or SHP-2, the only two proteins currently known to bind to gp130 at this site.     

Contrasting levels of genetic diversity between the common, self-compatible Liparis kumokiri and rare, self-incompatible Liparis makinoana (Orchidaceae) in South Korea

Levels of allozyme variation and intrapopulation spatial genetic structure of the two terrestrial clonal orchids Liparis kumokiri , a self-compatible relatively common species, and L. makinoana , a self-incompatible rare species, were examined for 17 ( N  = 1875) and four ( N  = 425) populations, respectively, in South Korea. Populations of L. makinoana harboured high levels of genetic variation ( H _e = 0.319) across 15 loci. In contrast, L. kumokiri exhibited a complete lack of allozyme variation ( H _e = 0.000). Considering the lack of genetic variability, it is suggested that current populations of L. kumokiri in South Korea originated from a genetically depauperate ancestral population. For L. makinoana , a significant deficit of heterozygosity (mean F _IS = 0.198) was found in population samples excluding clonal ramets, suggesting that pollen dispersal is localized, generating biparental inbreeding. The significant fine-scale genetic structuring (≤ 2 m) found in a previous study, in addition to the moderate levels of population differentiation ( F _ST = 0.107) and the significant relationship between genetic and geographical distances ( r  = 0.680) found here, suggests a leptokurtic distribution of seed dispersal for L. makinoana . Although populations of L. makinoana harbour high levels of genetic variation, they are affected by a recent genetic bottleneck. This information suggests that genetic drift and limited gene flow could be the main evolutionary forces for speciation of a species-rich genus such as Liparis .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 41–48.     

内蒙古天然与放牧草原温室气体排放研究

采用静态箱-气相色谱法测定内蒙古典型草原温室气体排放。结果表明,四类天然草原吸收CH4、排放N2O和CO2各自有其相对固定的季节变化形式,四类草原和大气交换温室气体通量的变化形式基本一致,受年度气候变化所控制,而土壤、植被类型、降雨量等天然因素和放牧强度等人为因素仅影响排放强度。与天然羊草草原相比,自由放牧降低了羊草草原对CH4的吸收和N2O排放,增加了CO2的排放。     

Isolation and characterization of microsatellite markers in Perilla frutescens Brit

We isolated and characterized 13 polymorphic microsatellite primers from Perilla frutescens Brit. var. frutescens by using a modified method that involves one‐way PCR amplification with single primer prior to enrichment with an ‘oligo hook’. The efficiency of this procedure for isolating unique microsatellite sequences was approximately 77%. The number of alleles per microsatellite locus ranged from three to 10 with an average of 6.5 alleles per locus while fragment size varied from 156 to 298 bp. The observed and expected heterozygosities ranged from 0.52 to 0.86 and 0.52 to 0.89, respectively. These newly isolated microsatellite markers are expected to provide valuable resources for different genetic studies currently underway in our Perilla genome research program.     

The ADP-ribosyltransferase PARP10/ARTD10 Interacts with Proliferating Cell Nuclear Antigen (PCNA) and Is Required for DNA Damage Tolerance

All cells rely on genomic stability mechanisms to protect against DNA alterations. PCNA is a master regulator of DNA replication and S-phase-coupled repair. PCNA post-translational modifications by ubiquitination and SUMOylation dictate how cells stabilize and re-start replication forks stalled at sites of damaged DNA. PCNA mono-ubiquitination recruits low fidelity DNA polymerases to promote error-prone replication across DNA lesions. Here, we identify the mono-ADP-ribosyltransferase PARP10/ARTD10 as a novel PCNA binding partner. PARP10 knockdown results in genomic instability and DNA damage hypersensitivity. Importantly, we show that PARP10 binding to PCNA is required for translesion DNA synthesis. Our work identifies a novel PCNA-linked mechanism for genome protection, centered on post-translational modification by mono-ADP-ribosylation.     

The usage of marker traits in plants for evaluation of resistance of the winter wheat to pest insects

A new method of selection of the winter wheat varieties has been tested for resistance to the pest insects' complex by the traits of plants that are the markers of plant resistance. It makes it possible to use this method from year to year independently of the pests' density.     

A preferential role for STAT5, not constitutively active STAT3, in promoting survival of a human lymphoid tumor

STATs are believed to play key roles in normal and abnormal cell function. In the present work, we investigated the role of STATs in an IL-2-responsive human lymphoblastic lymphoma-derived cell line, YT. Only STAT3 was found constitutively tyrosine phosphorylated, but not other STATs. Hyperactive STAT3 was not attributable to a pre-existing intermediate affinity IL-2R complex and/or hyperactive Jak activity. Depletion of STAT3 protein expression reduced tumor cell viability with protracted kinetics (72-96 h), while TUNEL assays demonstrated cell death occurred via apoptosis. Interestingly, depletion of STAT5 in this same tumor induced more pronounced cell death compared with STAT3 depletion (24 h). Although IL-2 was able to rescue STAT3-depleted cells from death, it could not compensate for the loss of STAT5. To determine the prosurvival function of STAT3 vs STAT5 within the same tumor model, genes were profiled in STAT3- or STAT5-depleted YT cells by apoptosis-specific microarrays. Several differentially expressed genes were identified. Interestingly, those genes involved in NF-kappaB regulation, such as TNFR-associated factors 2 and 5 and B cell leukemia/lymphoma 10, were readily decreased upon STAT5, but not STAT3, depletion as validated by quantitative RT-PCR. These results suggest that STAT5 and, to a lesser extent, hyperactive STAT3 provide preferential and critical cell survival signals for certain human lymphoid tumors, indicating that nonhyperactive STATs should be considered as therapeutic targets for abrogating tumorigenesis.     

Characterization of new microsatellite markers in mung bean,Vigna radiata (L.)

The present work reports the isolation and characterization of new polymorphic microsatellites in mung bean (Vigna radiata L.). Of 93 designed primer pairs, seven were found to amplify polymorphic microsatellite loci, which were then characterized using 34 mung bean accessions. The number of alleles ranged from two to five alleles per locus with an average of three alleles. Observed and expected heterozygosity values ranged from 0 to 0.088 and from 0.275 to 0.683, respectively. All seven loci showed significant deviations from Hardy–Weinberg equilibrium, whereas only one pairwise combination (GBssr‐MB77 and GBssr‐MB91) exhibited significant departure from linkage disequilibrium. These newly developed markers are currently being utilized for diversity assessment within the mung bean germplasm collection of the Korean Gene Bank.