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101.
Delta-like 1 homolog (Dlk1) is important in myogenesis. However, the roles of different Dlk1 isoforms have not been investigated. In C2C12 cell lines producing different Dlk1 isoforms, membrane-bound Dlk1 promoted the hypertrophic phenotype and a higher fusion rate, whereas soluble Dlk1 inhibited myotube formation. Inversed expression patterns of genes related to myogenic differentiation further support these phenotypic changes. In addition, temporal expression and balance between the Dlk1 isoforms have a regulatory role in myogenesis in vivo. Collectively, Dlk1 isoforms have distinctive effects on myogenesis, and its regulation during myogenesis is critical for normal muscle development. 相似文献
102.
Dongxue Shao Meimi Zhao Jianjun Xu Rui Feng Feng Guo Huiyuan Hu Xuefei Sun Qinghua Gao Guilin He Wei Sun Hongmei Wang Lifeng Yu Suyuan Liu Yaonan Zhu Etsuko Minobe Tong Zhu Masaki Kameyama Liying Hao 《FEBS letters》2014
The present study examined the binding of the individual N- and C-lobes of calmodulin (CaM) to Cav1.2 at different Ca2+ concentration ([Ca2+]) from ≈ free to 2 mM, and found that they may bind to Cav1.2 Ca2+-dependently. In particular, using the patch-clamp technique, we confirmed that the N- or C-lobes can rescue the basal activity of Cav1.2 from run-down, demonstrating the functional relevance of the individual lobes. The data imply that at resting [Ca2+], CaM may tether to the channel with its single lobe, leading to multiple CaM molecule binding to increase the grade of Ca2+-dependent regulation of Cav1.2. 相似文献
103.
Keita Nagasawa Takeshi Tarui Shigeru Yoshida† Fumiko Sekiguchi Maho Matsunami Ai Ohi Kazuki Fukami Seiji Ichida‡ Hiroyuki Nishikawa§ Atsufumi Kawabata 《Journal of neurochemistry》2009,108(3):676-684
We investigated if stimulation of T-type Ca2+ channels with sodium hydrosulfide (NaHS), a donor of hydrogen sulfide (H2 S), could cause neuronal differentiation of NG108-15 cells. Like dibutyryl cyclic AMP (db-cAMP), treatment with NaHS at 1.5–13.5 mM for 16 h enhanced neurite outgrowth in a concentration-dependent manner. Synergistic neuritogenic effect was obtained in the cells stimulated with NaHS in combination with db-cAMP at subeffective concentrations. Exposure to NaHS or db-cAMP for 2 days resulted in enhancement of expression of high-voltage-activated currents consisting of N-, P/Q-, L- and also other types, but not of T-type currents. Mibefradil, a pan-T-type channel blocker, abolished the neuritogenesis induced by NaHS, but not by db-cAMP. The NaHS-evoked neuritogenesis was also completely blocked by pretreatment with BAPTA/AM, a chelator of intracellular Ca2+ , and by zinc chloride at a concentration known to selectively inhibit Cav 3.2 isoform of T-type Ca2+ channels, but not Cav 3.1 or Cav 3.3. Further, l -ascorbate, recently proven to selectively inhibit Cav 3.2, abolished the neuritogenic effect of NaHS, but not db-cAMP. Our data thus demonstrate that NaHS/H2 S is a novel inducer of neuronal differentiation in NG108-15 cells, as characterized by neuritogenesis and expression of high-voltage-activated currents, and suggest the involvement of T-type Ca2+ channels, especially Cav 3.2. 相似文献
104.
WU Su-Kung 《植物分类学报:英文版》2002,40(6):530-538
Tectaria Cav. is a large fern genus of ca. 150 species distributed in the tropic and subtropic regions of the world, of which 27 species and two varieties occur in China. These species are
mostly distributed in the southern part to the Yangtze River, mainly concentrated in Yunnan, only
two species spreading northwards to Sichuan located in the northern part to the Yangtze River. Based
on examination of specimens deposited in KUN and PE, many of which are recent collections, a new
species is described, one species and one variety are recognized as new records for China, one species as new record for Yunnan, one species as new record for Guizhou, and four specific names, i.
e., T. cosimilis Ching et C. H. Wang, T. decurrenti-alata Ching et C. H. Wang, T. fengii
Ching et C. H. Wang, T. simaoensis Ching et C. H. Wang are reduced to synonymies. As a re-suit, 22 species and two varieties are recognized in the genus Tectaria from Yunnan. 相似文献
105.
Molecular mapping of the blast resistance gene, Pi44(t), in a line derived from a durably resistant rice cultivar 总被引:12,自引:0,他引:12
D.-H. Chen M. dela Viña T. Inukai D. J. Mackill P. C. Ronald R. J. Nelson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(6-7):1046-1053
A recombinant inbred line derived from a cross between CO39 and ‘Moroberekan’, RIL276, was found to be resistant to lineage
44 isolates of Pyricularia grisea in the Philippines. One hundred F2 individuals were obtained from a backcross of RIL276 and CO39. Phenotypic analysis showed that RIL276 carries a single locus,
tentatively named Pi44(t), conferring complete resistance to lineage 44 isolates of P. grisea. RFLP probes, STS primers and AFLP markers were applied to identify DNA markers linked to Pi44(t). Neither RFLP nor STS-PCR analysis gave rise to DNA markers linked to the locus. Using bulk segregant AFLP analysis, however,
two dominant AFLP markers (AF348 and AF349) linked to Pi44(t) were identified. AF349 and AF348 were located at 3.3±1.5 cM and 11±3.5 cM from Pi44(t), respectively. These markers were mapped on chromosome 11 using an F2 population derived from a cross between ‘Labelle’ and ‘Black Gora’. The location of AF348 on chromosome 11 was confirmed using another F2 mapping population derived from IR40931-26-3-3-5/ PI543851. DNA products at the loci linked to Pi44(t) were amplified from RIL276, ‘Labelle’ and PI543851 using the same primer pairs used to amplify AF349 and AF348. Sequence analysis of these bands showed 100% identity between lines. This result indicates that these AFLP markers could
be used for the comparison of maps or assignment of linkage groups to chromosomes.
Received: 12 May 1998 / Accepted: 13 November 1998 相似文献
106.
《Channels (Austin, Tex.)》2013,7(4):370-375
Voltage-gated calcium channels (VGCCs), calmodulin (CaM), and calmodulin kinase II (CaMKII) are essential for various nervous system functions. CaM and CaMKII differentially regulate calcium dependent facilitation (CDF) and calcium dependent inactivation (CDI) of the Cav1 and Cav2 families of VGCCs. It is generally accepted that conserved structures in the C-terminus of these channels regulate CDF and CDI, and yet recent evidence indicates that other intracellular regions may be involved. We recently discovered that N-terminal sequences in Cav1.2 bind CaM and CaMKII, and function to regulate CDI as well as surface expression and open probability, respectively. Cav1 and Cav2 share significant portions of N-terminal sequence and therefore we explored whether homologous binding sites might exist in Cav2.1. Here, we show that like the proximal N-terminus of Cav1.2, the homologous region of Cav2.1 contains sequences which interact either directly or indirectly with CaM. 相似文献
107.
Carlos Gonzalez Gustavo F. Contreras Alexander Peyser Peter Larsson Alan Neely Ramón Latorre 《Biophysical reviews》2012,4(1):1-15
Placed in the cell membrane (a two-dimensional environment), ion channels and enzymes are able to sense voltage. How these proteins are able to detect the difference in the voltage across membranes has attracted much attention, and at times, heated debate during the last few years. Sodium, Ca2+ and K+ voltage-dependent channels have a conserved positively charged transmembrane (S4) segment that moves in response to changes in membrane voltage. In voltage-dependent channels, S4 forms part of a domain that crystallizes as a well-defined structure consisting of the first four transmembrane (S1–S4) segments of the channel-forming protein, which is defined as the voltage sensor domain (VSD). The VSD is tied to a pore domain and VSD movements are allosterically coupled to the pore opening to various degrees, depending on the type of channel. How many charges are moved during channel activation, how much they move, and which are the molecular determinants that mediate the electromechanical coupling between the VSD and the pore domains are some of the questions that we discuss here. The VSD can function, however, as a bona fide proton channel itself, and, furthermore, the VSD can also be a functional part of a voltage-dependent phosphatase. 相似文献
108.
109.
Regulation of L-type CaV1.3 channel activity and insulin secretion by the cGMP-PKG signaling pathway
《Cell calcium》2017
cGMP is a second messenger widely used in the nervous system and other tissues. One of the major effectors for cGMP is the serine/threonine protein kinase, cGMP-dependent protein kinase (PKG), which catalyzes the phosphorylation of a variety of proteins including ion channels. Previously, it has been shown that the cGMP-PKG signaling pathway inhibits Ca2+ currents in rat vestibular hair cells and chromaffin cells. This current allegedly flow through voltage-gated CaV1.3L-type Ca2+ channels, and is important for controlling vestibular hair cell sensory function and catecholamine secretion, respectively. Here, we show that native L-type channels in the insulin-secreting RIN-m5F cell line, and recombinant CaV1.3 channels heterologously expressed in HEK-293 cells, are regulatory targets of the cGMP-PKG signaling cascade. Our results indicate that the CaVα1 ion-conducting subunit of the CaV1.3 channels is highly expressed in RIN-m5F cells and that the application of 8-Br-cGMP, a membrane-permeable analogue of cGMP, significantly inhibits Ca2+ macroscopic currents and impair insulin release stimulated with high K+. In addition, KT-5823, a specific inhibitor of PKG, prevents the current inhibition generated by 8-Br-cGMP in the heterologous expression system. Interestingly, mutating the putative phosphorylation sites to residues resistant to phosphorylation showed that the relevant PKG sites for CaV1.3 L-type channel regulation centers on two amino acid residues, Ser793 and Ser860, located in the intracellular loop connecting the II and III repeats of the CaVα1 pore-forming subunit of the channel. These findings unveil a novel mechanism for how the cGMP-PKG signaling pathway may regulate CaV1.3 channels and contribute to regulate insulin secretion. 相似文献
110.
Andrew P Braun 《Channels (Austin, Tex.)》2013,7(4):229-230
It is well recognized clinically that fever in young children (< 6 y of age) may lead to seizure activity in a small, but significant percentage of these individuals, which may have negative consequences for the developing brain and progressive cognitive function. In rodent models, exposure of acute brain slices to hyperthermic temperatures (i.e., 38–41°C) is reported to evoke membrane depolarization and increased neuronal firing, although the underlying molecular/cellular events responsible for these phenomena are not fully understood. Elevated temperature may alter membrane excitability by influencing individual ion channels within a given neuron, or alter the behavior and connectivity of neurons and glia that operate within a local network. In the present study, Radzicki and colleagues have examined the possibility that modest increases in tissue/body temperature (up to 40.5°C) may enhance the activity of voltage-gated Ca2+ channels, which could then promote spontaneous firing of individual neurons and greater network discharge. The results of this work indicate that fever-like temperatures positively and reversibly influence the gating properties of L-type Ca2+ channels, and that the L-type blocker nimodipine reduces both temperature-induced increases in spontaneous neuronal firing and the incidence/duration of discharge activity in a whole animal model of febrile seizure. 相似文献