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111.
Blasig IE Winkler L Lassowski B Mueller SL Zuleger N Krause E Krause G Gast K Kolbe M Piontek J 《Cellular and molecular life sciences : CMLS》2006,63(4):505-514
Tight junctions seal intercellular clefts via membrane-related strands, hence, maintaining important organ functions. We investigated
the self-association of strand-forming transmembrane tight junction proteins. The regulatory tight junction protein occludin
was differently tagged and cotransfected in eucaryotic cells. These occludins colocalized within the plasma membrane of the
same cell, coprecipitated and exhibited fluorescence resonance energy transfer. Differently tagged strand-forming claudin-5
also colocalized in the plasma membrane of the same cell and showed fluorescence resonance energy transfer. This demonstrates
self-association in intact cells both of occludin and claudin-5 in one plasma membrane. In search of dimerizing regions of
occludin, dimerization of its cytosolic C-terminal coiledcoil domain was identified. In claudin-5, the second extracellular
loop was detected as a dimer. Since the transmembrane junctional adhesion molecule also is known to dimerize, the assumption
that homodimerization of transmembrane tight junction proteins may serve as a common structural feature in tight junction
assembly is supported.
Received 6 October 2005; received after revision 14 December 2005; accepted 27 December 2005
†These authors contributed equally to this work. 相似文献
112.
The serine/threonine protein phosphatase 2A (PP2A) represents a large family of highly conserved heterotrimeric enzymes. Their
critical importance in cell homeostasis is underlined by the fact that they are targets of natural toxins like the tumor promoter
okadaic acid, and of simian virus 40 small tumor antigen (SV40 small t), a viral protein known to promote cell transformation.
Furthermore, mutated or lower expression levels of PP2A subunits have been found in certain cancers. One major known event
in PP2A-dependent cell transformation is the alteration of key signaling pathways that control cell growth and survival. In
this review, we focus on how PP2A enzymes also affect cell adhesion and cytoskeletal dynamics, the disruption of which is
linked to loss of cell polarity, increased cell motility and invasiveness. We also examine how those various pathways participate
in the transforming activity of SV40 small t.
Received 29 June 2006; received after revision 3 August 2006; accepted 20 September 2006 相似文献
113.
In human patients, blood coagulation disorders often associate with cancer, even in its early stages. Recently, in vitro and in vivo experimental models have shown that oncogene expression, or inactivation of tumour suppressor genes, upregulate genes that
control blood coagulation. These studies suggest that activation of blood clotting, leading to peritumoral fibrin deposition,
is instrumental in cancer development. Fibrin can indeed build up a provisional matrix, supporting the invasive growth of
neoplastic tissues and blood vessels. Interference with blood coagulation can thus be considered as part of a multifaceted
therapeutic approach to cancer.
Received 30 November 2005; received after revision 7 February 2005; accepted 8 February 2006 相似文献
114.
On the basis of evidence collected from the literature, we propose a general model by which protein kinase (PK) A and the
different PKC isoforms can inversely affect cell growth. Molecular switches, which are able to direct the signal towards antiproliferative
or mitogenic pathways, are the different isoforms of Raf and PKC. Conflicting data are also reported and discussed in an attempt
to reconcile them.
Received 10 November 2005; received after revision 28 December 2005; accepted 3 January 2006 相似文献
115.
Relation between total and exchangeable sodium in the body 总被引:1,自引:0,他引:1
116.
主要讨论带参数微分方程边值问题的逼近值及渐近值解法,并且利用基础解系、边值函数等概念,解决了带参数的微分方程中参数充分小的范围内解的变化趋势. 相似文献
117.
<正> This paper shows how the so called von Karman model can be obtained as a singular limitof a modified Mindlin-Timoshenko system when the modulus of elasticity in shear k tends to infinity,provided a regularizing term through a fourth order dispersive operator is added.Introducing dampingmechanisms,the authors also show that the energy of solutions for this modified Mindlin-Timoshenkosystem decays exponentially,uniformly with respect to the parameter k.As k→∞,the authors obtainthe damped von Karman model with associated energy exponentially decaying to zero as well. 相似文献
118.
Model-set is utilized in state estimation for maneuvering target tracking.Two minimal symmetric model-subsets are designed and investigated by moment matching method,which include hypersphere-symmetric model-subset and axis-symmetric model-subset,if system mode is a random variable and obeys certain probability distribution.They can be used as the fundamental model-subset for multiple models estimation with fixed structure,variable structure and moving bank.The model-groups constructed by above designed subsets are given,which give the practical guidance for use of model-set in multiple models approach with a variable structure.Simulation results show that the performances of two minimal model-set significantly outperform the corresponding model-sets with fixed spacing. 相似文献
119.
120.
This paper argues that Venezuelan community organizations (COs) are playing a substantial role in the building of a new social order in which elements such as rights, equity, and justice are being displaced from a universal narrative toward more local narratives. This displacement is enwrapped in a discourse on the political participation of citizens in the running of public affairs, which implies a redefinition of the role of COs and the state beyond the usually accepted sphere of COs. The need to unfold the sense of COs thus becomes paramount for understanding our present and its current manifestations of an epochal change. 相似文献