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131.
Songhee Jeon Jung-Keug Park Chang-Dae Bae Joobae Park 《Neurochemistry international》2010,56(6-7):810-818
Moesin is a member of ERM family proteins which act as the cross-linkers between plasma membrane and actin-cytoskeleton and is activated by phosphorylation at Thr-558. In neurons, suppression of radixin and moesin alters the growth cone morphology. However, the significance of phosphorylation of ERM proteins in neuronal cells has not been fully investigated. In this study, we studied the signaling pathways responsible for moesin phosphorylation and its functional importance in NGF-treated PC12 cells. NGF rapidly induced the phosphorylation of moesin at Thr-558 in PC12 cells which was dependent on PI3K and Rac1. We found that Akt interacted and phosphorylated with moesin both in vitro and in vivo. Inhibition of PI3K and Rac1 abolished the NGF-induced Akt activation, indicating that Akt is at the downstream of PI3K and Rac1. To examine the functional role of phosphorylated ERM proteins, a dominant negative mutant form of moesin (T558A) was introduced into PC12 cells. The mutant significantly reduced the frequency of cells with neurites following NGF treatment. Our results indicate that PI3K, Rac1 and Akt-dependent phosphorylation of moesin is required for the NGF-induced neurite formation in differentiating PC12 cells. 相似文献
132.
W. Y. Jung J. E. Kim K. C. Jung D. I. Jin C. Moran E. W. Park J. T. Jeon J. H. Lee 《Animal genetics》2010,41(1):89-92
Xenotransplantation from pigs provides a possible solution to the shortage of human organs for allotransplantation. Porcine endogenous retroviruses (PERVs) are a possible obstacle to using porcine organs in addition to the immunological barriers. Three main types of PERVs (A, B and C) have been previously investigated in diverse pig breeds. To examine the copy numbers of PERVs and their genomic locations in the Korean native pig genome, we screened a BAC (Bacterial Artificial Chromosome) library with PERV-specific protease primers for initial recognition of PERV-positive clones and three sets of envelope-specific primers for the identification of PERV types. A total of 45 PERV-positive clones, nine PERV-A and 36 PERV-B, have been identified from the library screening and the BAC contigs were constructed using the primers designed from BAC end sequences (BESs). These primers were also used for SCH (Somatic Cell Hybrid) and RH (Radiation Hybrid) mapping of the PERV-positive clones. The results indicate that 45 PERV-positive BAC clones belong to nine contigs and a singleton. SCH and IMpRH (INRA-Minnesota Porcine Radiation Hybrid) mapping results indicated that there are at least eight separate PERV genomic locations, consisting of three PERV-A and five PERV-B. One contig could not be mapped, and two contigs are closely located on SSC7. Southern blotting indicates there may be up to 15 additional sites. Further investigation of these clones will contribute to a general strategy to generate PERV-free lines of pigs suitable for xenotransplantation. 相似文献
133.
So-Yeon Hong Young-Mi Jeon Hyun-Jung Lee Jong-Ghee Kim Jin-A. Baek Jeong-Chae Lee 《Molecular and cellular biochemistry》2010,335(1-2):263-272
The precise mechanism by which Rho kinase translates the mechanical signals into OPN up-regulation in force-exposed fibroblasts has not been elucidated. Human periodontal ligament fibroblasts (hPLFs) were exposed to mechanical force by centrifuging the culture plates at a magnitude of 50 g/cm2 for 60 min. At various times of the force application, they were processed for analyzing cell viability, trypan blue exclusion, and OPN expression at protein and RNA levels. Cellular mechanism(s) of the force-induced OPN up-regulation was also examined using various kinase inhibitors or antisense oligonucleotides specific to mechanosensitive factors. Centrifugal force up-regulated OPN expression and induced a rapid and transient increase in the phosphorylation of focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), and Elk1. Pharmacological blockade of RhoA/Rho-associated coiled coil-containing kinase (ROCK) signaling markedly reduced force-induced FAK and ERK1/2 phosphorylation. Transfecting hPLFs with FAK antisense oligonucleotide diminished ERK1/2 activation and force-induced OPN expression. Further, ERK inhibitor inhibited significantly OPN expression, Elk1 phosphorylation, and activator protein-1 (AP-1)-DNA binding activation, but not FAK phosphorylation, in the force-applied cells. These results demonstrate that FAK signaling plays critical roles in force-induced OPN expression in hPLFs through interaction with Rho/ROCK as upstream effectors and ERK-Elk1/ERK-c-Fos as downstream effectors. 相似文献
134.
Han-Ok Cho Chak-Sum Ho Yu-Joo Lee In-Cheol Cho Sung-Soo Lee Moon-Suck Ko Chankyu Park Douglas M. Smith Jin-Tae Jeon Jun-Heon Lee 《Molecules and cells》2010,29(5):493-499
The highly polymorphic porcine major histocompatibility complex (MHC), or the swine leukocyte antigens (SLA), has been repeatedly
associated with variations in swine immune response to pathogens and vaccines as well as with production traits. The SLA antigens
are also important targets for immunological recognition of foreign tissue grafts. We recently established a resource population
of Korean native pigs as models for human transplantation and xenotransplantation research. In this study, 115 animals derived
from three generations of the Korean native pigs were genotyped for three SLA class I (SLA-2, SLA-3 and SLA-1) and three SLA
class II loci (DRB1, DQB1, DQA) using PCR with sequence-specific primers (PCR-SSP) at the allele group resolution. A total
of seven SLA haplotypes (Lr-5.34, Lr-7.23, Lr-31.13, Lr-56.23, Lr-56.30, Lr-59.1, Lr-65.34), comprising six unique class I
and five unique class II haplotypes, were characterized in the founding animals. Class I haplotype Lr-65.0 and class II haplotype
Lr-0.34 were novel; and together with Lr-56.0 these haplotypes appeared to be breed-specific. In the progeny population, Lr-7.23
and Lr-56.30 appeared to be the most prevalent haplotypes with frequencies of 34.7% and 31.6%, respectively; the overall homozygosity
was 27.4%. This resource population of SLA-defined Korean native pigs will be useful as large animal models for various transplantation
and xenotransplantation experiments, as well as for dissecting the roles of SLA proteins in swine disease resistance and production
traits. 相似文献
135.
Rap1 is rapidly activated upon chemoattractant stimulation and plays an important role in cell adhesion and cytoskeletal reorganization
during chemotaxis. Here, we demonstrate that G-protein coupled receptors and G-proteins are essential for chemoattractant-mediated
Rap1 activation in Dictyostelium. The rapid Rap1 activation upon cAMP chemoattractant stimulation was absent in cells lacking chemoattractant cAMP receptors
cAR1/cAR3 or a subunit of the heterotrimeric G-protein complex Gα2. Loss of guanylyl cyclases GCA/SGC or a cGMP-binding protein
GbpC exhibited no effect on Rap1 activation kinetics. These results suggest that Rap1, a key regulator for the regulation
of cytoskeletal reorganization during cell movement, is activated through the G-protein coupled receptors cAR1/cAR3 and Gα2
proteins in a way independent of the cGMP signaling pathway. 相似文献
136.
137.
Jin Woo Park Sang Kyoon Kim Taslim Ahmed Al-Hilal Ok Cheol Jeon Hyun Tae Moon Youngro Byun 《Biotechnology and Bioprocess Engineering》2010,15(1):66-75
Advances in biotechnology, gene manipulation, and protein engineering for macromolecule drugs, such as insulin, parathyroid
hormone (PTH), calcitonin, human growth hormone, erythropoietin (EPO), and peptide YY (PYY) allow commercial production in
large scale for diverse therapeutic uses. Other macromolecules, such as mucopolysaccharide heparin, have expanded markets
through improvements in their pharmacokinetic and pharmacological effects. However, most products are available only as injectable
forms and are limited to patients with no alternative therapeutic choices. Orally available macromolecule formulations are
still unmet needs for improving patient compliance and expanding administration paradigms and indications. Oral delivery technologies
including carrier systems, absorption enhancers, protease inhibitors, and modification by conjugating transporter or receptor
recognition molecules have been developed and some are undergoing clinical studies. In this review, we discuss major obstacles
for oral absorption of macromolecule drugs and summarize recent strategies to overcome the huddles related to enhancing intestinal
permeation. 相似文献
138.
139.
Kyung Sook Chung So Yeon Yoo Seong Jeon Yoo Jong Seob Lee Ji Hoon Ahn 《Plant signaling & behavior》2010,5(9):1102-1104
Transition to the flowering stage is precisely controlled by a few classes of regulatory molecules. BROTHER OF FT AND TFL1 (BFT) is a member of FLOWERING LOCUS T (FT)/TERMINAL FLOWER 1 (TFL1) family, an important class of flower development regulators with unidentified biochemical function. BFT has a TFL1-like activity and plays a role in axillary inflorescence development. To elucidate the expression pattern of BFT, we analyzed the subcellular localization and conditional expression of BFT in this study. We generated 35S::BFT:GFP plants to investigate the subcellular localization of BFT protein. 35S::BFT:GFP plants showed late flowering, similarly as did 35S::BFT plants. BFT:GFP fusion protein was localized in the nucleus and the plasma membrane, which was different from the localization pattern of FT and TFL1. BFT expression was induced by abiotic stress conditions. ABA, drought, and osmotic stress treatments induced BFT expression, whereas cold, salt, and heat stress conditions did not, suggesting that BFT plays a role in regulating flowering time and inflorescence structure under drought conditions. The induction pattern of BFT was different from those of other FT/TFL1 family genes. Our studies indicated that BFT showed a distinct expression pattern from its homologous genes during the vegetative growth in Arabidopsis.Key words: flowering time, flowering locus T, terminal flower 1, brother of FT and TFL1, abiotic stress, subcellullar localizationThe FLOWERING LOCUS T (FT)/TERMINAL FLOWER 1 (TFL1) family is a small gene family whose members play a pivotal role in flower development in Arabidopsis. The family includes FT, TFL1, TWIN SISTER OF FT (TSF), Arabidopsis thaliana CENTRORADIALIS homologue (ATC), MOTHER OF FT AND TFL1 (MFT) and BROTHER OF FT AND TFL1 (BFT).3,5,6,9,15,17 FT is a floral promoter that integrates signal inputs from various pathways that regulate flowering time in Arabidopsis.5,6 TFL1 plays an antagonistic role to that of FT, functioning as a floral inhibitor. Unlike FT, TFL1 also plays an important role in controlling plant architecture by regulating the expression of LEAFY (LFY) and APETALA1 (AP1), two important floral meristem identity genes in the shoot apical meristem (SAM).3,7 TSF regulates flowering by a mechanism similar to that of FT, although a lesion in TSF does not have an apparent effect on the determination of flowering time. MFT has a weak FT-like activity.17 ATC acts as a floral repressor, and its role is similar to that of TFL1.9 Finally, BFT has a TFL1-like activity, in spite of its amino acid homology to FT,2,4,16 and functions redundantly with TFL1 in inflorescence meristem development in Arabidopsis.16 Although genetic studies elucidated an intricate role of the FT/TFL1 family genes, not much is known about the expression pattern of the remaining members except FT and TFL1. Here, we report that BFT expression showed a distinct pattern from its homologous genes during the vegetative phase. BFT:GFP fusion protein was detected in the nucleus and the plasma membrane. BFT expression was induced by abiotic stress conditions, distinct from other FT/TFL1 family genes, raising the possibility that BFT plays a role in regulating flowering time and inflorescence structure under drought conditions. 相似文献
140.
A single-compartmented microbial fuel cell composed of a graphite felt anode modified with Neutral Red (NR-anode) and a porous
Fe(II)-carbon cathode (FeC-cathode) were compared for electricity generation from Microbacterium sp. and Pseudomonas sp. under identical conditions. Pseudomonas sp. was more than four times the size of Microbacterium sp. based on SEM images. In cyclic voltammetry, the redox reaction between Microbacterium sp and electrode was three times the rate observed between Pseudomonas sp. and the electrode based on the Y-axis (current) variation of cyclic voltammogram. The electric power generated by Microbacterium sp. was approx 3–4 times higher than that with Pseudomonas sp. during incubation for more than 150 days in the fuel cell. 相似文献