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1.
The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –14CO2 fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes. 相似文献
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Tuomas Huovinen Kalle Rytkönen Urpo Lamminmäki Teijo Pellinen 《Biotechnology letters》2013,35(1):47-53
Estrogen receptor (ER) modulators are a serious health issue but estrogenic compounds, especially antagonists of ER function, are widely screened for in search of novel therapeutics against hormonal diseases such as the breast cancer. Here we report a novel and a simple bioassay for estrogenic and anti-estrogenic compounds based on ligand-dependent recruitment of ER co-activator steroid receptor co-activator 1 (SRC-1) to purified Renilla luciferase-tagged ERα. In this assay, in vivo-biotinylated (E. coli) SRC-1, purified Renilla luciferase-ERα, and the analyte sample are mixed and incubated for 2 h in a streptavidin-coated microtiter wells, and after one washing step, luminescence is measured with a simple instrument. The assay does not require chemical labeling of the components and shows good sensitivity (25 pM E2) and wide dynamic range of more than four orders of magnitude. 相似文献
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Pellinen T Tuomi S Arjonen A Wolf M Edgren H Meyer H Grosse R Kitzing T Rantala JK Kallioniemi O Fässler R Kallio M Ivaska J 《Developmental cell》2008,15(3):371-385
Adherent cells undergo remarkable changes in shape during cell division. However, the functional interplay between cell adhesion turnover and the mitotic machinery is poorly understood. The endo/exocytic trafficking of integrins is regulated by the small GTPase Rab21, which associates with several integrin alpha subunits. Here, we show that targeted trafficking of integrins to and from the cleavage furrow is required for successful cytokinesis, and that this is regulated by Rab21. Rab21 activity, integrin-Rab21 association, and integrin endocytosis are all necessary for normal cytokinesis, which becomes impaired when integrin-mediated adhesion at the cleavage furrow fails. We also describe a chromosomal deletion and loss of Rab21 gene expression in human cancer, which leads to the accumulation of multinucleate cells. Importantly, reintroduction of Rab21 rescued this phenotype. In conclusion, Rab21-regulated integrin trafficking is essential for normal cell division, and its defects may contribute to multinucleation and genomic instability, which are hallmarks of cancer. 相似文献
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Anja Mai Stefan Veltel Teijo Pellinen Artur Padzik Eleanor Coffey Varpu Marjom?ki Johanna Ivaska 《The Journal of cell biology》2011,194(2):291-306
Integrin trafficking from and to the plasma membrane controls many aspects of cell behavior including cell motility, invasion, and cytokinesis. Recruitment of integrin cargo to the endocytic machinery is regulated by the small GTPase Rab21, but the detailed molecular mechanisms underlying integrin cargo recruitment are yet unknown. Here we identify an important role for p120RasGAP (RASA1) in the recycling of endocytosed α/β1-integrin heterodimers to the plasma membrane. Silencing of p120RasGAP attenuated integrin recycling and augmented cell motility. Mechanistically, p120RasGAP interacted with the cytoplasmic domain of integrin α-subunits via its GAP domain and competed with Rab21 for binding to endocytosed integrins. This in turn facilitated exit of the integrin from Rab21- and EEA1-positive endosomes to drive recycling. Our results assign an unexpected role for p120RasGAP in the regulation of integrin traffic in cancer cells and reveal a new concept of competitive binding of Rab GTPases and GAP proteins to receptors as a regulatory mechanism in trafficking. 相似文献
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Adult spinal opioid receptor μ1 expression after incision is altered by early life repetitive tactile and noxious procedures in rats
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Nynke J. van den Hoogen Roel RI van Reij Jacob Patijn Dick Tibboel Elbert A. J. Joosten 《Developmental neurobiology》2018,78(4):417-426
Clinical and experimental data suggests that noxious stimulation at critical stages of development results in long‐term changes on nociceptive processing in later life. Here, we use an established, well‐documented rat model of repetitive noxious procedures closely mimicking the clinical situation in the NICU. In order to understand molecular changes underlying the long‐term consequences of repetitive stimulation of the developing nociceptive system the present study aims to analyze the presence of the µ‐opioid‐receptor‐1 (OPRM1). Neonatal rats received either four needle pricks per day in the left hind‐paw from postnatal day 0–7 as a model of procedural pain in infancy. Control pups were handled in the same way but were instead tactile stimulated, or were left undisturbed. At the age of 8 weeks, all animals received an ipsilateral hind‐paw incision as a model for post‐operative pain, and mechanical sensitivity was tested at multiple time‐points. Before, and 1 or 5 days post‐incision, spinal cord tissue was collected for immunostaining of opioid receptor OPRM1. Semi‐quantitative immunocytochemical analysis of superficial laminae in lumbar spinal dorsal horn revealed that: (1) early life repetitive tactile or noxious procedures do not alter baseline levels of OPRM1 staining intensity and (2) early life repetitive tactile or noxious procedures lead to a decrease in OPRM1 staining intensity 5 days after incision in adulthood compared to undisturbed controls. We conclude that early life repetitive tactile or noxious procedures affect the intensity of OPRM1‐immunoreactivity in the lumbar superficial spinal cord dorsal horn after adulthood injury, without affecting baseline intensity. © 2018 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 78: 417–426, 2018 相似文献
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The involvement of mitochondria and the caspase-9 activation pathway in rituximab-induced apoptosis in FL cells 总被引:1,自引:0,他引:1
Jonna Eeva Ulla Nuutinen Antti Ropponen Mikko Mättö Mine Eray Riikka Pellinen Jarmo Wahlfors Jukka Pelkonen 《Apoptosis : an international journal on programmed cell death》2009,14(5):687-698
Despite the wide use of anti-CD20 antibody rituximab in the cancer treatment of B cell malignancies, the signalling pathways
of CD20-induced apoptosis are still not understood. By using dominant negative (DN)-caspase-9 overexpressing follicular lymphoma
cells we demonstrated that the activation of caspase-9 was essential for rituximab-mediated apoptosis. The death receptor
pathway mediated by caspase-8 activation was not involved in rituximab-mediated apoptosis since overexpression of FLIPshort or FLIPlong proteins, inhibitors of caspase-8 activation, could not inhibit rituximab-induced apoptosis. However, the death receptor
pathway activation by anti-Fas antibodies showed an additive effect on rituximab-induced apoptosis. The stabilisation of the
mitochondrial outer membrane by Bcl-xL overexpression inhibited cell death, showing the important role of mitochondria in rituximab-induced apoptosis. Interestingly,
the rituximab-induced release of cytochrome c and collapse of mitochondrial membrane potential were regulated by caspase-9. We suggest that caspase-9 and downstream caspases
may feed back to mitochondria to amplify mitochondrial disruption during intrinsic apoptosis. 相似文献
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Jukka Pellinen Eino Väisänen Mirja Salkinoja-Salonen Gösta Brunow 《Applied microbiology and biotechnology》1984,20(1):77-82
Summary The degradation of dimeric phenylpropanoid lignin model compounds using mixed bacterial cultures was studied. The six model compounds contained the most common linkages of lignin: -O-4, -, -5, and -1. The results indicate that it is possible to enrich bacteria which are able to degrade all these compounds. Bacteria were also able to use these dimers as the sole source of carbon for growth. In view of these results it seems probable that bacterial inability to degrade polymeric lignin is due to the physical properties such as the molecular size of lignin. 相似文献