Abstract：
:The couplons of the cardiomyocyte form nanospaces within the cell that place the L-type calcium channel (Ca(v)1.2), situated on the plasmalemma, in opposition to the type 2 ryanodine receptor (RyR2), situated on the sarcoplasmic reticulum. These two molecules, which form the basis of excitation-contraction coupling, are separated by a very limited space, which allows a few Ca(2+) ions passing through Ca(v)1.2 to activate the RyR2 at concentration levels that would be deleterious to the whole cell. The limited space also allows Ca(2+) inactivation of Ca(v)1.2. We have found that not all couplons are the same and that their properties are likely determined by their molecular partners which, in turn, determine their excitability. In particular, there are a class of couplons that lie outside the RyR2-Ca(v)1.2 dyad; in this case, the RyR2 is close to caveolin-3 rather than Ca(v)1.2. These extra-dyadic couplons are probably controlled by the multitude of molecules associated with caveolin-3 and may modulate contractile force under situations such as stress. It has long been assumed that like the skeletal muscle, the RyR2 in the couplon are arranged in a structured array with the RyR2 interacting with each other via domain 6 of the RyR2 molecule. This arrangement was thought to provide local control of RyR2 excitability. Using 3D electron tomography of the couplon, we show that the RyR2 in the couplon do not form an ordered pattern, but are scattered throughout it. Relatively few are in a checkerboard pattern--many RyR2 sit edge-to-edge, a configuration which might preclude their controlling each other's excitability. The discovery of this structure makes many models of cardiac couplon function moot and is a current avenue of further research.
journal_name
Protoplasmajournal_title
Protoplasmaauthors
Asghari P,Scriven DR,Hoskins J,Fameli N,van Breemen C,Moore EDdoi
10.1007/s00709-011-0347-5subject
Has Abstractpub_date
2012-02-01 00:00:00pages
S31-8eissn
0033-183Xissn
1615-6102journal_volume
249 Suppl 1pub_type
杂志文章,评审相关文献
PROTOPLASMA文献大全abstract：:The subtribe Cajaninae of papilionoid legumes has a pantropical distribution and comprises approximately 490 species. These species have diversified throughout dry environments where there are high temperatures and strong light. The subtribe stands out because all its representatives have vesicular glands. In addition...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-018-1307-0
更新日期：2019-03-01 00:00:00
abstract：:With the goal of evaluating the factors that may be influencing the reproductive success of an endangered, terrestrial orchid Cypripedium japonicum Thunb., the anatomical and morphological characteristics of seed development were assessed, as were the levels of endogenous hormones to investigate the possible relations...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-017-1128-6
更新日期：2017-11-01 00:00:00
abstract：:Single-molecule Förster resonance energy transfer (smFRET) has emerged as a powerful tool for elucidating biological structure and mechanisms on the molecular level. Here, we focus on applications of smFRET to study interactions between DNA and enzymes such as DNA and RNA polymerases. SmFRET, used as a nanoscopic rule...
journal_title：Protoplasma
pub_type： 杂志文章,评审
doi：10.1007/s00709-013-0596-6
更新日期：2014-03-01 00:00:00
abstract：:Proper mitochondrial morphogenesis is crucial for successful development of motile sperm. It was known that recessive Drosophila melanogaster mutation emm caused anomalies in the formation of a mitochondrial derivative--nebenkern and led to male sterility. Here we identified primary mutation effect and showed that emm...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-012-0434-2
更新日期：2013-04-01 00:00:00
abstract：:Turions, which are modified shoot apices, are vegetative, dormant overwintering organs produced by perennial aquatic plants. In this study, the turion cytochemistry and ultrastructure of Aldrovanda vesiculosa, Utricularia vulgaris and U. stygia were compared with particular emphasis placed on storage substances. These...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-014-0646-8
更新日期：2014-11-01 00:00:00
abstract：:Pollen development and germination were adversely affected by the presence of mercury, whereas low-concentrations stimulated the whole procedure. Mercury caused morphological anomalies during the tube growth, characterized by irregularly increasing diameters and swelling tips. The main effect was the anomalous cell wa...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-017-1192-y
更新日期：2018-05-01 00:00:00
abstract：:The LIM domain is an evolutionary conserved double-zinc finger motif found in a variety of proteins exhibiting diverse biological roles. LIM domains have been observed to act as modular protein-binding interfaces mediating protein-protein interactions in the cytoplasm and the nucleus. Interaction of LIM domains with s...
journal_title：Protoplasma
pub_type： 杂志文章,评审
doi：10.1007/s007090200000
更新日期：2002-02-01 00:00:00
abstract：:Tradescantia virginiana leaf epidermal cells were plasmolysed by sequential treatment with 0.8 M and 0.3 M sucrose. Plasmolysis revealed adhesion of the plasma membrane to the cell wall at sites coinciding with cytoskeletal arrays involved in the polarisation of cells undergoing asymmetric divisions--cortical actin pa...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/BF01280301
更新日期：2001-01-01 00:00:00
abstract：:Along the past recent years, two-photon excitation (TPE) microscopy has moved from the realms of technical curiosity to be a standard application in many advanced cell biology laboratories. The growing body of literature covered in this review points out the obvious advantages of TPE over any other imaging method base...
journal_title：Protoplasma
pub_type： 杂志文章,评审
doi：10.1007/s00709-003-0026-2
更新日期：2004-03-01 00:00:00
abstract：:Previous complementation of a chitin synthase class Vb null mutant (Colletotrichum graminicola chsA) indicated that the encoded protein is responsible for approximately 30% of the conidial chitin, is essential for conidial wall strength in media with high water potential, and contributes to strength of hyphal tips. We...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-005-0126-2
更新日期：2006-05-01 00:00:00
abstract：:Superoxide dismutase (SOD) activities of the oomycete Phytophthora cinnamomi were examined. Five polypeptides with manganese superoxide dismutase (MnSOD) activity were found in mycelium growing in liquid culture with relative molecular weights ranging from approximately 25 to 100 kDa. Comparison with characterized avo...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-012-0464-9
更新日期：2013-06-01 00:00:00
abstract：:19F nuclear magnetic resonance (NMR) imaging and 19F NMR chemical-shift imaging (19F CSI) have been used to localize fluorinated compounds administered to stems of Ancistrocladus heyneanus and A. abbreviatus for the elucidation of biosynthetic pathways in living plants. This first application of 19F CSI on plants prov...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/BF01306603
更新日期：2001-01-01 00:00:00
abstract：:Intracellular molecular transport and localization are crucial for cells (plant cells as much as mammalian cells) to proliferate and to adapt to diverse environmental conditions. Here, some aspects of the microscopy-based method of fluorescence recovery after photobleaching (FRAP) are introduced. In the course of the ...
journal_title：Protoplasma
pub_type： 杂志文章,评审
doi：10.1007/s00709-013-0604-x
更新日期：2014-03-01 00:00:00
abstract：:Marcetia taxifolia (A. St.-Hil.) DC. hosts two gall morphotypes, a pistil-shaped gall induced by a Cecidomyiidae (Diptera) and a fusiform stem gall induced by a Lepidoptera. The cytological study of these galls aimed to answer how the difference in nutritive tissues of Diptera and Lepidoptera galls could be explained ...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-015-0759-8
更新日期：2015-09-01 00:00:00
abstract：:The directional elongation of root hairs, "tip growth", depends on the coordinated and highly regulated trafficking of vesicles which fill the tip cytoplasm and are active in secretion of cell wall material. So far, little is known about the dynamics of endocytosis in living root hairs. We analyzed the motile behaviou...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-005-0103-9
更新日期：2005-10-01 00:00:00
abstract：:In this paper, we investigated whether nitric oxide (NO) participated in the regulation of the ascorbate-glutathione (AsA-GSH) cycle by exogenous jasmonic acid (JA) in the leaves of wheat seedlings under drought stress. The findings of our study showed that drought stress significantly enhanced the AsA-GSH cycle by up...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-015-0756-y
更新日期：2015-09-01 00:00:00
abstract：:Mastigonemes, tripartite tubular hairs on the anterior flagellum of Phytophthora zoospores, are instrumental for disease dissemination to new host plants. A previous study showed that PnMas2 was part of the tubular shaft of Phytophthora parasitica mastigonemes. In the current study, genes encoding two related proteins...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-018-1314-1
更新日期：2019-03-01 00:00:00
abstract：:The distribution and development of secretory cells and crystal cells in young shoot apexes of water hyacinth were investigated through morphological and cytological analysis. The density of secretory cells and crystal cells were high in parenchyma tissues around the vascular bundles of shoot apexes. Three development...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-010-0157-1
更新日期：2011-04-01 00:00:00
abstract：:Capitate glandular trichomes (CGT) of sunflower, Helianthus annuus, synthesize bioactive sesquiterpene lactones (STLs) within a short period of only a few days during trichome development. In the current project, the subcellular localization of H. annuus germacrene A monooxygenase (HaGAO), a key enzyme of the STL bios...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-015-0823-4
更新日期：2016-03-01 00:00:00
abstract：:Interactive effects of two heavy metal pollutants Cd and Pb in the growth medium were examined on their uptake, production of reactive oxygen species (ROS), induction of oxidative stress and antioxidative defence responses in Indica rice (Oryza sativa L.) seedlings. When rice seedlings in sand culture were exposed to ...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-014-0614-3
更新日期：2014-09-01 00:00:00
abstract：:Earwigs (Dermaptera) use different strategies to increase their reproductive success. Most species lay eggs; however, viviparity of the matrotrophic type has been reported in two groups: Hemimeridae and Arixeniidae. In Arixeniidae, offspring develop in two separate places: inside an ovary (the intraovarian phase) and ...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-019-01402-1
更新日期：2019-11-01 00:00:00
abstract：:Salinity and drought are important abiotic stresses limiting plant growth and development. Late embryogenesis abundant (LEA) proteins are a group of proteins associated with tolerance to water-related stress. We previously cloned an LEA gene, SmLEA, from Salvia miltiorrhiza Bunge. Phylogenetic analysis indicated that ...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-014-0626-z
更新日期：2014-09-01 00:00:00
abstract：:Ripening which leads to fruit senescence is an inimitable process characterized by vivid changes in color, texture, flavor, and aroma of the fleshy fruits. Our understanding of the mechanisms underlying the regulation of fruit ripening and senescence is far from complete. Molecular and biochemical studies on tomato (S...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-015-0836-z
更新日期：2016-03-01 00:00:00
abstract：:We used an ultraviolet microbeam to cut individual kinetochore spindle fibres in metaphase crane-fly spermatocytes. We then followed the growth of the "kinetochore stubs", the remnants of kinetochore fibres that remain attached to kinetochores. Kinetochore stubs elongate with constant velocity by adding tubulin subuni...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-007-0265-8
更新日期：2007-01-01 00:00:00
abstract：:Understanding the mechanisms that microbes exploit to invade host cells and cause disease is crucial if we are to eliminate their threat. Although pathogens use a variety of microbial factors to trigger entry into non-phagocytic cells, their targeting of the host cell process of endocytosis has emerged as a common the...
journal_title：Protoplasma
pub_type： 杂志文章,评审
doi：10.1007/s00709-010-0164-2
更新日期：2010-08-01 00:00:00
abstract：:Present communication reports laboratory and pot experiments conducted to study the influence of water and osmotic stress on nitrogen uptake and metabolism in two wheat (Triticum aestivum L) cultivars with and without potassium supplementation. Polyethylene glycol 6000-induced osmotic stress/restricted irrigation caus...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-017-1086-z
更新日期：2017-09-01 00:00:00
abstract：:The original version of this article unfortunately contains a mistake. ...
journal_title：Protoplasma
pub_type： 杂志文章,已发布勘误
doi：10.1007/s00709-019-01348-4
更新日期：2019-05-01 00:00:00
abstract：:Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and is characterized by multistage formation. The presence of ductular reaction, cytokeratin 7 positivity (PCK7), and increased levels of gamma glutamyltransferase (γGT) has been observed during liver carcinogenesis and contribute to tum...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-016-1000-0
更新日期：2017-03-01 00:00:00
abstract：:Podophyllum species (Podophyllum hexandrum Royle and Podophyllum peltatum) are a major source of deriving anticancer drugs from their major chemical constituent, podophyllotoxin. However, information lacks on regulatory components of podophyllotoxin biosynthesis; therefore, different classes of transcription factors w...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-015-0938-7
更新日期：2017-01-01 00:00:00
abstract：:The cryptomonad nucleomorph is a vestigial nucleus of a eukaryotic red alga engulfed by a phagotrophic protist and retained as a photosynthetic endosymbiont. This review recounts the initial discovery and subsequent characterisation of the cryptomonad nucleomorph focusing on the key role of Peter Sitte and his protégé...
journal_title：Protoplasma
pub_type： 杂志文章
doi：10.1007/s00709-017-1153-5
更新日期：2017-09-01 00:00:00
