scholarly journals Nanoarchaeum equitans and Ignicoccus hospitalis: New Insights into a Unique, Intimate Association of Two Archaea

2007 ◽  
Vol 190 (5) ◽  
pp. 1743-1750 ◽  
Author(s):  
Ulrike Jahn ◽  
Martin Gallenberger ◽  
Walter Paper ◽  
Benjamin Junglas ◽  
Wolfgang Eisenreich ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Mutual Influence ◽  
Strong Dependence ◽  
Gas Stripping ◽  
Electron Microscopic ◽  
Intimate Association ◽  
Cell Components ◽  
Ignicoccus Hospitalis ◽  
Nanoarchaeum Equitans ◽  
Structural Connection

ABSTRACT Nanoarchaeum equitans and Ignicoccus hospitalis represent a unique, intimate association of two archaea. Both form a stable coculture which is mandatory for N. equitans but not for the host I. hospitalis. Here, we investigated interactions and mutual influence between these microorganisms. Fermentation studies revealed that during exponential growth only about 25% of I. hospitalis cells are occupied by N. equitans cells (one to three cells). The latter strongly proliferate in the stationary phase of I. hospitalis, until 80 to 90% of the I. hospitalis cells carry around 10 N. equitans cells. Furthermore, the expulsion of H2S, the major metabolic end product of I. hospitalis, by strong gas stripping yields huge amounts of free N. equitans cells. N. equitans had no influence on the doubling times, final cell concentrations, and growth temperature, pH, or salt concentration ranges or optima of I. hospitalis. However, isolation studies using optical tweezers revealed that infection with N. equitans inhibited the proliferation of individual I. hospitalis cells. This inhibition might be caused by deprivation of the host of cell components like amino acids, as demonstrated by 13C-labeling studies. The strong dependence of N. equitans on I. hospitalis was affirmed by live-dead staining and electron microscopic analyses, which indicated a tight physiological and structural connection between the two microorganisms. No alternative hosts, including other Ignicoccus species, were accepted by N. equitans. In summary, the data show a highly specialized association of N. equitans and I. hospitalis which so far cannot be assigned to a classical symbiosis, commensalism, or parasitism.

The interaction of Nanoarchaeum equitans with Ignicoccus hospitalis: proteins in the contact site between two cells

2009 ◽  
Vol 37 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Tillmann Burghardt ◽  
Benjamin Junglas ◽  
Frank Siedler ◽  
Reinhard Wirth ◽  
Harald Huber ◽  
...  
Keyword(s):  
Protein Complex ◽  
Direct Contact ◽  
Cell Surfaces ◽  
Contact Site ◽  
Electron Microscopic ◽  
Intimate Association ◽  
Ignicoccus Hospitalis ◽  
Nanoarchaeum Equitans ◽  
Cell Envelopes ◽  
Microscopic Investigations

The two archaea Ignicoccus hospitalis and Nanoarchaeum equitans form a unique intimate association, the character of which is not yet fully understood. Electron microscopic investigations show that at least two modes of cell–cell interactions exist: (i) the two cells are interconnected via thin fibres; and (ii) the two cell surfaces are in direct contact with each other. In order to shed further light on the molecules involved, we isolated a protein complex, by using detergent-induced solubilization of cell envelopes, followed by a combination of chromatography steps. Analysis by MS and comparison with databases revealed that this fraction contained two dominant proteins, representing the respective major envelope proteins of the two archaea. In addition, a considerable set of membrane proteins is specifically associated with these proteins. They are now the focus of further biochemical and ultrastructural investigations.

scholarly journals Myosin VI: cellular functions and motor properties

2004 ◽  
Vol 359 (1452) ◽  
pp. 1931-1944 ◽  
Author(s):  
K. C. Holmes ◽  
D. R. Trentham ◽  
R. Simmons ◽  
Rhys Roberts ◽  
Ida Lister ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Leading Edge ◽  
Force Transducer ◽  
Myosin Vi ◽  
Cellular Functions ◽  
Electron Microscopic ◽  
Coated Pits ◽  
Microscopic Studies ◽  
Golgi Network

Myosin VI has been localized in membrane ruffles at the leading edge of cells, at the trans–Golgi network compartment of the Golgi complex and in clathrin–coated pits or vesicles, indicating that it functions in a wide variety of intracellular processes. Myosin VI moves along actin filaments towards their minus end, which is the opposite direction to all of the other myosins so far studied (to our knowledge), and is therefore thought to have unique properties and functions. To investigate the cellular roles of myosin VI, we identified various myosin VI binding partners and are currently characterizing their interactions within the cell. As an alternative approach, we have expressed and purified full–length myosin VI and studied its in vitro properties. Previous studies assumed that myosin VI was a dimer, but our biochemical, biophysical and electron microscopic studies reveal that myosin VI can exist as a stable monomer. We observed, using an optical tweezers force transducer, that monomeric myosin VI is a non–processive motor which, despite a relatively short lever arm, generates a large working stroke of 18 nm. Whether monomer and/or dimer forms of myosin VI exist in cells and their possible functions will be discussed.

scholarly journals Proteomic Characterization of Cellular and Molecular Processes that Enable the Nanoarchaeum equitans-Ignicoccus hospitalis Relationship

PLoS ONE ◽  
2011 ◽  
Vol 6 (8) ◽  
pp. e22942 ◽  
Author(s):  
Richard J. Giannone ◽  
Harald Huber ◽  
Tatiana Karpinets ◽  
Thomas Heimerl ◽  
Ulf Küper ◽  
...  
Keyword(s):  
Molecular Processes ◽  
Ignicoccus Hospitalis ◽  
Nanoarchaeum Equitans

scholarly journals Ignicoccus hospitalis sp. nov., the host of ‘Nanoarchaeum equitans’

2007 ◽  
Vol 57 (4) ◽  
pp. 803-808 ◽  
Author(s):  
Walter Paper ◽  
Ulrike Jahn ◽  
Michael J. Hohn ◽  
Michaela Kronner ◽  
Daniela J. Näther ◽  
...  
Keyword(s):  
Type Strain ◽  
Novel Species ◽  
Protein Composition ◽  
High Similarity ◽  
The North ◽  
Physiological Properties ◽  
Cell Architecture ◽  
Ignicoccus Hospitalis ◽  
Nanoarchaeum Equitans ◽  
Unique Cell

A novel chemolithoautotrophic and hyperthermophilic member of the genus Ignicoccus was isolated from a submarine hydrothermal system at the Kolbeinsey Ridge, to the north of Iceland. The new isolate showed high similarity to the two species described to date, Ignicoccus islandicus and Ignicoccus pacificus, in its physiological properties as well as in its unique cell architecture. However, phylogenetic analysis and investigations on the protein composition of the outer membrane demonstrated that the new isolate was clearly distinct from I. islandicus and I. pacificus. Furthermore, it is the only organism known so far which is able to serve as a host for ‘Nanoarchaeum equitans’, the only cultivated member of the ‘Nanoarchaeota’. Therefore, the new isolate represents a novel species of the genus Ignicoccus, which we name Ignicoccus hospitalis sp. nov. (type strain KIN4/IT=DSM 18386T=JCM 14125T).

Feline Cystic Thymoma: A Clinicopathologic, Immunohistologic, and Electron Microscopic Study of 14 Cases

2003 ◽  
Vol 5 (1) ◽  
pp. 27-35 ◽  
Author(s):  
AK Patnaik ◽  
PH Lieberman ◽  
RA Erlandson ◽  
C Antonescu
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Epithelial Cells ◽  
Smooth Muscle Actin ◽  
Muscle Actin ◽  
Electron Microscopic ◽  
Germinal Centres ◽  
Factor Viii Antigen ◽  
Cell Components ◽  
Microscopic Features

Cystic thymoma was diagnosed in 14 cats in a period of 6 years. The most common clinical sign was laboured breathing. The tumours were characterized by various-sized cystic spaces with central vessels. The epithelial cells varied from oval to spindle to polygonal cells enclosing cystic spaces or in pure epithelial cell components. The nuclei of the neoplastic cells had scattered chromatin and small nucleoli. The cytoplasm was pale eosinophilic. The concentration of mature lymphocytes varied from area to area with rare germinal centres. Immunohistochemically, the epithelial cells stained only with AE1/AE3. The central vessels were positive for vimentin, smooth muscle actin, and factor VIII antigen. Electron microscopy revealed that the cyst walls were lined by epithelial cells that were joined by desmosomes, and the walls were well separated from the cystic spaces by a well-defined basement membrane. The neoplastic epithelial cells contained scattered tonofilaments. Three of the cats had metastasis to the lymph nodes and lungs. Two novel cases of ectopic cystic thymoma have also been described. Results of this study reveal that cystic thymoma is uncommon in cats, and that the histomorphologic, immunohistochemical, and electron microscopic features are similar to those of cystic thymoma in humans.

Insights into the Structures of Superoxide Reductases from the Symbionts Ignicoccus hospitalis and Nanoarchaeum equitans

Biochemistry ◽  
2018 ◽  
Vol 57 (36) ◽  
pp. 5271-5281 ◽  
Author(s):  
Célia V. Romão ◽  
Pedro M. Matias ◽  
Cristiana M. Sousa ◽  
Filipa G. Pinho ◽  
Ana F. Pinto ◽  
...  
Keyword(s):  
Ignicoccus Hospitalis ◽  
Nanoarchaeum Equitans

scholarly journals Life on the edge: functional genomic response of Ignicoccus hospitalis to the presence of Nanoarchaeum equitans

2014 ◽  
Vol 9 (1) ◽  
pp. 101-114 ◽  
Author(s):  
Richard J Giannone ◽  
Louie L Wurch ◽  
Thomas Heimerl ◽  
Stanton Martin ◽  
Zamin Yang ◽  
...  
Keyword(s):  
Functional Genomic ◽  
Ignicoccus Hospitalis ◽  
Nanoarchaeum Equitans ◽  
Genomic Response

OBSERVATIONS ON THE LOCALIZATION OF LABELLED AMINO ACID IN MOUSE ADRENAL CHROMAFFIN CELLS AFTER THE INJECTION OF l-[4,5-3H]LEUCINE

1978 ◽  
Vol 78 (1) ◽  
pp. 21-29 ◽  
Author(s):  
S. KOBAYASHI ◽  
CHRISTINE KENT ◽  
R. E. COUPLAND
Keyword(s):  
Amino Acid ◽  
Golgi Complex ◽  
Chromaffin Cells ◽  
Intracellular Localization ◽  
Cell Organelles ◽  
Electron Microscopic ◽  
Cortical Cells ◽  
Electron Microscopic Autoradiography ◽  
Cell Components ◽  
Adrenal Chromaffin

The intracellular localization of l-[4,5-3H]leucine in chromaffin cells has been observed using light and electron microscopic autoradiography and the association of the labelled amino acid with particular cell components confirmed by statistical analysis. By making observations at short intervals after a single intravenous pulse of [3H]leucine it has been possible to follow the movement of the isotope from the endoplasmic reticulum through the Golgi complex to the chromaffin granules. No evidence for movement of the label through the Golgi complex was observed in adjacent cortical cells. The time sequence of transport of the amino acid through the various cell organelles was very similar to that observed by previous workers in protein-secreting exocrine cells.

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