The New Frontier, From Dicty to Nano
From~Kathryn’s Corner~Have We been raked over a Nanobarrel
by Slime? Seems these scientists are one up on us, or they think so.
Dictyostelium seems to arise everywhere!
Nanotubes and Cells at Max Planck
interactions of carbon nanotubes and the amoeba Dictyostelium at the Max Planck Institute for Dynamics and Self-Organization in 2006.
Is this nanomachine both natural and artificial, producing novel and synthetic products in the body?
To show these scientists have lost their mind: They are going to kill dicty with vibrio cholerae. Now, this is total genius. It tells us here that gene products are delivered by D. discoideum. They say: “Despite an increasing understanding of the components that make up the T6SS apparatus, little is known about the regulation of these genes and the gene products delivered by this nanomachine.”…………..So we know what we are looking for, but cholorae to kill it. Is that the best that can be done?
Vibrio cholerae Requires the Type VI Secretion System Virulence Factor VasX To Kill Dictyostelium discoideum
The type VI secretion system (T6SS) is recognized as an important virulence mechanism in several Gram-negative pathogens. In Vibrio cholerae, the causative agent of the diarrheal disease cholera, a minimum of three gene clusters—one main cluster and two auxiliary clusters—are required to form a functional T6SS apparatus capable of conferring virulence toward eukaryotic and prokaryotic hosts. Despite an increasing understanding of the components that make up the T6SS apparatus, little is known about the regulation of these genes and the gene products delivered by this nanomachine. VasH is an important regulator of the V. cholerae T6SS. Here, we present evidence that VasH regulates the production of a newly identified protein, VasX, which in turn requires a functional T6SS for secretion. Deletion of vasX does not affect export or enzymatic function of the structural T6SS proteins Hcp and VgrG-1, suggesting that VasX is dispensable for the assembly of the physical translocon complex. VasX localizes to the bacterial membrane and interacts with membrane lipids. We present VasX as a novel virulence factor of the T6SS, as a V. cholerae mutant lacking vasX exhibits a phenotype of attenuated virulence toward Dictyostelium discoideum.….
” In 1968, the O37 serogroup strain V52 was responsible for an outbreak of cholera-like diarrheal illness in Sudan, with 460 cases leading to 125 deaths (42). The genome of V52 carries both CT and TCP genes, but whether this strain produces CT and TCP in vivo has not yet been determined. V52 possesses a constitutively active type VI secretion system (T6SS) that confers virulence toward phagocytic cells, including the social amoeba Dictyostelium discoideum and murine macrophages (34). Pandemic strains of V. cholerae also possess the full complement of T6SS genes, but it is currently unclear how the T6SS is activated and how this system contributes to human disease. “
. The recently discovered T6SS is predicted to structurally resemble the cell-puncturing device of T4 bacteriophage and to function similarly to the T3SS and T4SS, which transfer proteins directly from the microbe into host cells . Recent work has demonstrated that the T6SS can target prokaryotic as well as eukaryotic organisms .
This would tell us that the T3SS and T4SS are affiliated with the dicty. So now since we know the ribosomes were constructed over 40 years ago, the phage comes in handy to do the dirty work, of vectoring in these apparatuses. the T6SS resembles the T4phage. So, we know these were used. Below is where the agrobacterium comes in.
“The T6SS gene clusters include several conserved genes that encode needle apparatus components (4, 20, 28, 33), inner and outer membrane proteins (2, 24, 29, 34), and transcriptional regulators (3, 6, 28). V. cholerae utilizes the transcriptional activator VasH to control the expression of T6SS genes, such as hcp, for which there are two alleles (VCA0017 and VC1415) in the Vibrio genome (34). VasH is encoded by the large T6SS cluster (VCA0107 to VCA0123) and is predicted to activate sigma factor σ54-dependent transcription (6, 34). Another noteworthy protein is virulence-associated secretion protein K (VasK). VasK is a T6SS inner membrane protein that, in Agrobacterium tumefaciens, has a role in hydrolyzing nucleoside triphosphates for the T6SS machine assembly or secretion of T6SS substrates (24).
So the agrobacterium strain is part of the machine. the gall or biofilm, has to be there. It appears that agrobacterium does the hydrolyzing. More can be found at this link explaining how these scientists went from the frying pan into the fire. But, at least are trying to fix the error.Before dicty involvement, came the re constructed ribosome. That will be in another paper. but, Dicty is part of this machine. good comparisons Microscopy:
T3SS systems and what they do:
Type III Secretion Systems
In the 1980s and 1990s researchers studying Yersinia, a genus that causes human diseases ranging from bubonic plague to gastrointestinal disease, found that the bacteria produced proteins that were thought to be associated with the outer membrane called Yops. Yops lacked classical signal sequences and were not secreted via a sec-dependent pathway and thus were assumed to be delivered by a new type of secretion system, which later became known as a T3SS, representing its order of discovery in secretion systems.In the last 10 years T3SS have been identified in more than 20 bacterial pathogens that infect plants and animals (Table I). Although there is a high degree of conservation among the components of the type III apparatus in different bacterial species, the pathogens often carry a distinct set of virulence factors with a variety of functions that can be translocated into either animal or plant cells. The overall theme of these T3SS is the direct delivery of proteins that alter and in effect “hijack” the infected host cell for the pathogen
The following information gives us an idea how inorganic substances can work with organics.
Nanotomography is a technique of growing importance in the investigation of the shape, size, distribution and elemental composition of a wide variety of materials that are of central interest to investigators in the physical and biological sciences. Nanospatial factors often hold the key to a deeper understanding of the properties of matter at the nanoscale level. With recent advances in tomography, it is possible to achieve experimental resolution in the nanometre range, and to determine with elemental specificity the three-dimensional distribution of materials. This critical reviewdeals principally with electron tomography, but it also outlines the power and future potential of transmission X-ray tomography, and alludes to other related techniques.http://www.rsc.org/ej/CS/2007/b701569k/b701569k-f18.gif