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111.
Nikolaev S Montoya-Burgos JI Margulies EH;NISC Comparative Sequencing Program Rougemont J Nyffeler B Antonarakis SE 《PLoS genetics》2007,3(1):e2
Understanding the early evolution of placental mammals is one of the most challenging issues in mammalian phylogeny. Here, we addressed this question by using the sequence data of the ENCODE consortium, which include 1% of mammalian genomes in 18 species belonging to all main mammalian lineages. Phylogenetic reconstructions based on an unprecedented amount of coding sequences taken from 218 genes resulted in a highly supported tree placing the root of Placentalia between Afrotheria and Exafroplacentalia (Afrotheria hypothesis). This topology was validated by the phylogenetic analysis of a new class of genomic phylogenetic markers, the conserved noncoding sequences. Applying the tests of alternative topologies on the coding sequence dataset resulted in the rejection of the Atlantogenata hypothesis (Xenarthra grouping with Afrotheria), while this test rejected the second alternative scenario, the Epitheria hypothesis (Xenarthra at the base), when using the noncoding sequence dataset. Thus, the two datasets support the Afrotheria hypothesis; however, none can reject both of the remaining topological alternatives. 相似文献
112.
The eukaryotic translation termination factor eRF3 stimulates release of nascent polypeptides from the ribosome in a GTP-dependent manner. In most eukaryotes studied, eRF3 consists of an essential, conserved C-terminal domain and a nonessential, nonconserved N-terminal extension. However, in some species, this extension is required for efficient termination. Our data show that the N-terminal extension of Saccharomyces cerevisiae eRF3 also participates in regulation of termination efficiency, but acts as a negative factor, increasing nonsense suppression efficiency in sup35 mutants containing amino acid substitutions in the C-terminal domain of the protein. 相似文献
113.
114.
Tokalov SV Gutzeit HO 《Journal of experimental zoology. Part B. Molecular and developmental evolution》2007,308(2):127-138
Cell type-specific lectin binding is a useful tool for the analysis of developing systems. We describe the binding pattern of 21 different fluorescein isothiocyanate (FITC)-labelled lectins to the testis of two model teleost species, the medaka (Oryzias latipes) and the tilapia (Oreochromis niloticus). The analysis of the binding pattern was carried out on tissue sections (medaka and tilapia) and using primary culture cells (only tilapia). Lectin binding was studied by confocal microscopy and for histological analysis some sections were, in addition, stained with bodipy to gain additional information concerning the cytological organization of the cystic mode of spermatogenesis in fish. The observed differences in lectin staining of different cell types in primary cultures were quantified by flow cytometry. Only few lectins bound specifically to haploid cells while the reaction to diploid or tetraploid cells was generally stronger. However, the extracellular material around the haploid spermatids and spermatozoa in spermatocysts showed a strong staining reaction with several lectins (e.g., Phaseolus vulgaris Erythro agglutinin). The apparent differences in the cellular lectin-binding pattern can be used to identify particular cell types, to monitor their differentiation in vitro or to enrich particular cell types from heterogeneous cultures using magnetic beads coated with anti-FITC antibodies. Using the latter approach, we show that it is possible to enrich for gonial cells and at the same time deplete the preparation for haploid cells and Sertoli cells. 相似文献
115.
The voltage-gated potassium channel Kv4.3 was coexpressed with its beta-subunit Kv channel-interacting protein 2 and the angiotensin type 1 receptor in HEK-293 cells. Proteomic analysis of proteins coimmunoprecipitated with Kv4.3 revealed that Kv4.3 is associated with Rap guanine nucleotide exchange factors MR-GEF and EPAC-1. Previously, we demonstrated that Kv4.3 interacts with the angiotensin type 1 receptor in HE293 cells and cardiac myocytes. On the basis of this, we investigated the angiotensin type 1 receptor signaling to small G-proteins Ras and Rap-1 in the presence and absence of the Kv4.3-Kv channel-interacting protein 2 macromolecular complex. Ras activation was not significantly affected by coexpression of Kv4.3 and Kv channel-interacting protein 2. Ras exhibited a rapid activation-inactivation pattern with maximum activity at 2.5 min after addition of angiotensin II. In contrast, activation of Rap-1 was affected dramatically by coexpression of Kv4.3 and Kv channel-interacting protein 2 with the angiotensin type 1 receptor. In the absence of Kv4.3 and Kv channel-interacting protein 2, stimulation of the angiotensin type 1 receptor resulted in steady activation of Rap-1 that reached a plateau 25 min after addition of angiotensin II. In the presence of Kv4.3 and Kv channel-interacting protein 2, Rap-1 reaches a maximum activity 2.5 min after addition of angiotensin II and then deactivates rapidly, demonstrating a pattern of activation similar to that of Ras. Our findings show that Kv4.3 regulates angiotensin type 1 receptor signaling to the small G-protein Rap-1. 相似文献
116.
Alexander M. Matyushenko Daniil V. Shchepkin Denis S. Susorov Victoria V. Nefedova Galina V. Kopylova Valentina Y. Berg Sergey Y. Kleymenov Dmitrii I. Levitsky 《Biochemical and biophysical research communications》2019,508(3):934-939
Tropomyosin (Tpm) is an α-helical coiled-coil actin-binding protein that plays a key role in the Ca2+-regulated contraction of striated muscles. Two Tpm isoforms, α (Tpm 1.1) and β (Tpm 2.2), are expressed in fast skeletal muscles. These Tpm isoforms can form either αα and ββ homodimers, or αβ heterodimers. However, only αα-Tpm and αβ-Tpm dimers are usually present in most of fast skeletal muscles, because ββ-homodimers are relatively unstable and cannot exist under physiologic conditions. Nevertheless, the most of previous studies of myopathy-causing mutations in the Tpm β-chains were performed on the ββ-homodimers. In the present work, we applied different methods to investigate the effects of two myopathic mutations in the β-chain, Q147P and K49del (i.e. deletion of Lys49), on structural and functional properties of Tpm αβ-heterodimers and to compare them with the properties of ββ-homodimers carrying these mutations in both β-chains. The results show that the properties of αβ-Tpm heterodimers with these mutations in the β-chain differ significantly from the properties of ββ-homodimers with the same substitutions in both β-chains. This indicates that the αβ-heterodimer is a more appropriate model for studying the effects of myopathic mutations in the β-chain of Tpm than the ββ-homodimer which virtually does not exist in human skeletal muscles. 相似文献
117.
Sergey A. Samsonov Emilia A. Lubecka Krzysztof K. Bojarski Robert Ganzynkowicz Adam Liwo 《Biopolymers》2019,110(8):e23269
Heparin belongs to glycosaminoglycans (GAGs), a class of periodic linear anionic polysaccharides, which are functionally important components of the extracellular matrix owing to their interactions with various protein targets. Heparin is known to be involved in many cell signaling processes, while the experimental data available for heparin are significantly more abundant than for other GAGs. At the same time, the length and conformational flexibility of the heparin represent major challenges for its theoretical analysis. Coarse-grained (CG) approaches, which enable us to extend the size- and time-scale by orders of magnitude owing to reduction of system representation, appear, therefore, to be useful in simulating these systems. In this work, by using umbrella-sampling molecular dynamics simulations, we derived and parameterized the CG backbone-local potentials of heparin chains and the orientational potentials for the interactions of heparin with amino acid side chains to be further included in the physics-based Unified Coarse-Grained Model of biological macromolecules. With these potentials, simulations of extracellular matrix processes where both heparin and multiple proteins participate will be possible. 相似文献
118.
Hadiseh Dadras Sergey Boryshpolets Amin Golpour Tomas Policar Miroslav Blecha Borys Dzyuba 《Journal of fish biology》2019,95(4):1137-1144
Several factors regulating activation of spermatozoon motility in Eurasian burbot, Lota lota, including osmolality, calcium (Ca2+) ions, and temperature were investigated. Spermatozoon motility in Eurasian burbot, Lota lota was assessed at 4 and 30°C in seminal fluid, isotonic media (with and without Ca2+) and hypotonic media (with and without Ca2+). Spermatozoa were spontaneously activated in seminal fluid at 20°C and the maximum motility was recorded at 30°C, which is out of the spawning temperature range, indicating that no risk of activation occurs during routine semen handling in artificial insemination. Initiation of spermatozoon motility in L. lota is mediated by Ca2+ and sensitivity to Ca2+ is dependent on temperature. 相似文献
119.
Taras Antal Ivan Konyukhov Alena Volgusheva Tatyana Plyusnina Sergei Khruschev Galina Kukarskikh Sergey Goryachev Andrey Rubin 《Physiologia plantarum》2019,165(3):476-486
The development of high‐performance photobioreactors equipped with automatic systems for non‐invasive real‐time monitoring of cultivation conditions and photosynthetic parameters is a challenge in algae biotechnology. Therefore, we developed a chlorophyll (Chl) fluorescence measuring system for the online recording of the light‐induced fluorescence rise and the dark relaxation of the flash‐induced fluorescence yield (Qa? ? re‐oxidation kinetics) in photobioreactors. This system provides automatic measurements in a broad range of Chl concentrations at high frequency of gas‐tight sampling, and advanced data analysis. The performance of this new technique was tested on the green microalgae Chlamydomonas reinhardtii subjected to a sulfur deficiency stress and to long‐term dark anaerobic conditions. More than thousand fluorescence kinetic curves were recorded and analyzed during aerobic and anaerobic stages of incubation. Lifetime and amplitude values of kinetic components were determined, and their dynamics plotted on heatmaps. Out of these data, stress‐sensitive kinetic parameters were specified. This implemented apparatus can therefore be useful for the continuous real‐time monitoring of algal photosynthesis in photobioreactors. 相似文献
120.
Shtyrlin Valery G. Borissenok Valery A. Serov Nikita Yu. Simakov Vladimir G. Bragunets Vyacheslav A. Trunin Ivan R. Tereshkina Irina A. Koshkin Sergey A. Bukharov Mikhail S. Gilyazetdinov Edward M. Shestakov Evgeny E. Sirotkina Anna G. Zakharov Alexey V. 《Origins of life and evolution of the biosphere》2019,49(1-2):1-18
Origins of Life and Evolution of Biospheres - Syntheses under shock in nitrogen bubbled samples of the water – formamide – bicarbonate – sodium hydroxide system at... 相似文献