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Aeryun Kim Stephanie L. Servetas Jieun Kang Jinmoon Kim Sungil Jang Yun Hui Choi Hanfu Su Yeong-Eui Jeon Youngmin A. Hong Yun-Jung Yoo D. Scott Merrell Jeong-Heon Cha 《Journal of microbiology (Seoul, Korea)》2016,54(12):846-852
The array of outer membrane proteins (OMPs) found in Helicobacter pylori provides a crucial component for persistent colonization within the gastric niche. Not only does H. pylori harbor a wide number of OMPs, but these OMPs often vary across strains; this likely contributes to immune evasion, adaptation during long term colonization, and potentially differential disease progression. Previous work from our group described OMP differences among the Bab family (babA, babB, and babC) and Hom family (homA and homB) from 80 American H. pylori clinical isolates (AH) and 80 South Korean H. pylori clinical isolates (KH). In the current study, we expanded our investigation to include the less well characterized Hom family member, HomC. 相似文献
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Katharina Simon Stephanie Hennen Nicole Merten Stefanie Bl?ttermann Michel Gillard Evi Kostenis Jesus Gomeza 《The Journal of biological chemistry》2016,291(2):705-718
Recent studies have recognized G protein-coupled receptors as important regulators of oligodendrocyte development. GPR17, in particular, is an orphan G protein-coupled receptor that has been identified as oligodendroglial maturation inhibitor because its stimulation arrests primary mouse oligodendrocytes at a less differentiated stage. However, the intracellular signaling effectors transducing its activation remain poorly understood. Here, we use Oli-neu cells, an immortalized cell line derived from primary murine oligodendrocytes, and primary rat oligodendrocyte cultures as model systems to identify molecular targets that link cell surface GPR17 to oligodendrocyte maturation blockade. We demonstrate that stimulation of GPR17 by the small molecule agonist MDL29,951 (2-carboxy-4,6-dichloro-1H-indole-3-propionic acid) decreases myelin basic protein expression levels mainly by triggering the Gαi/o signaling pathway, which in turn leads to reduced activity of the downstream cascade adenylyl cyclase-cAMP-PKA-cAMP response element-binding protein (CREB). In addition, we show that GPR17 activation also diminishes myelin basic protein abundance by lessening stimulation of the exchange protein directly activated by cAMP (EPAC), thus uncovering a previously unrecognized role for EPAC to regulate oligodendrocyte differentiation. Together, our data establish PKA and EPAC as key downstream effectors of GPR17 that inhibit oligodendrocyte maturation. We envisage that treatments augmenting PKA and/or EPAC activity represent a beneficial approach for therapeutic enhancement of remyelination in those demyelinating diseases where GPR17 is highly expressed, such as multiple sclerosis. 相似文献
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David D. Stenehjem Michael Toole Joseph Merriman Kinjal Parikh Stephanie Daignault Sarah Scarlett Peg Esper Katherine Skinner Aaron Udager Srinivas Kiran Tantravahi David Gill Alli M. Straubhar Archana M. Agarwal Kenneth F. Grossmann Wolfram E. Samlowski Bruce Redman Neeraj Agarwal Ajjai Alva 《Cancer immunology, immunotherapy : CII》2016,65(8):941-949
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Jara Radeck Susanne Gebhard Peter Shevlin Orchard Marion Kirchner Stephanie Bauer Thorsten Mascher Georg Fritz 《Molecular microbiology》2016,100(4):607-620
Protection against antimicrobial peptides (AMPs) often involves the parallel production of multiple, well‐characterized resistance determinants. So far, little is known about how these resistance modules interact and how they jointly protect the cell. Here, we studied the interdependence between different layers of the envelope stress response of Bacillus subtilis when challenged with the lipid II cycle‐inhibiting AMP bacitracin. The underlying regulatory network orchestrates the production of the ABC transporter BceAB, the UPP phosphatase BcrC and the phage‐shock proteins LiaIH. Our systems‐level analysis reveals a clear hierarchy, allowing us to discriminate between primary (BceAB) and secondary (BcrC and LiaIH) layers of bacitracin resistance. Deleting the primary layer provokes an enhanced induction of the secondary layer to partially compensate for this loss. This study reveals a direct role of LiaIH in bacitracin resistance, provides novel insights into the feedback regulation of the Lia system, and demonstrates a pivotal role of BcrC in maintaining cell wall homeostasis. The compensatory regulation within the bacitracin network can also explain how gene expression noise propagates between resistance layers. We suggest that this active redundancy in the bacitracin resistance network of B. subtilis is a general principle to be found in many bacterial antibiotic resistance networks. 相似文献