Motile ghosts of the halophilic archaeon, Haloferax volcanii

Archaea swim using the archaellum (archaeal flagellum), a reversible rotary motor consisting of a torque-generating motor and a helical filament, which acts as a propeller. Unlike the bacterial flagellar motor (BFM), ATP (adenosine-5′-triphosphate) hydrolysis probably drives both motor rotation and filamentous assembly in the archaellum. However, direct evidence is still lacking due to the lack of a versatile model system. Here, we present a membrane-permeabilized ghost system that enables the manipulation of intracellular contents, analogous to the triton model in eukaryotic flagella and gliding Mycoplasma. We observed high nucleotide selectivity for ATP driving motor rotation, negative cooperativity in ATP hydrolysis, and the energetic requirement for at least 12 ATP molecules to be hydrolyzed per revolution of the motor. The response regulator CheY increased motor switching from counterclockwise (CCW) to clockwise (CW) rotation. Finally, we constructed the torque–speed curve at various [ATP]s and discuss rotary models in which the archaellum has characteristics of both the BFM and F1-ATPase. Because archaea share similar cell division and chemotaxis machinery with other domains of life, our ghost model will be an important tool for the exploration of the universality, diversity, and evolution of biomolecular machinery.

Motile ghosts of the halophilic archaeon, Haloferax volcanii

SummaryMotility is seen across all domains of life1. Prokaryotes exhibit various types of motilities, such as gliding, swimming, and twitching, driven by supramolecular motility machinery composed of multiple different proteins2. In archaea only swimming motility is reported, driven by the archaellum (archaeal flagellum), a reversible rotary motor consisting of a torque-generating motor and a helical filament which acts as a propeller3,4. Unlike the bacterial flagellar motor (BFM), adenosine triphosphate (ATP) hydrolysis probably drives both motor rotation and filamentous assembly in the archaellum5,6. However, direct evidence is still lacking due to the lack of a versatile model system. Here we present a membrane-permeabilized ghost system that enables the manipulation of intracellular contents, analogous to the triton model in eukaryotic flagella7 and gliding Mycoplasma8,9. We observed high nucleotide selectivity for ATP driving motor rotation, negative cooperativity in ATP hydrolysis and the energetic requirement for at least 12 ATP molecules to be hydrolyzed per revolution of the motor. The response regulator CheY increased motor switching from counterclockwise (CCW) to clockwise (CW) rotation, which is the opposite of a previous report10. Finally, we constructed the torque-speed curve at various [ATP]s and discuss rotary models in which the archaellum has characteristics of both the BFM and F1-ATPase. Because archaea share similar cell division and chemotaxis machinery with other domains of life11,12, our ghost model will be an important tool for the exploration of the universality, diversity, and evolution of biomolecular machinery.

EFFECTS OF KARMIZOLE DERIVATE ON THE EXPRESSION OF APO A-I GENE IN THE RAT’S HYPERLIPIDEMIA MODEL

Azoles are the main antifungal drug class. The main mechanism of the azoles action is the intercalation in the sterol biosynthesis regulation. At the same time, the effect of the azole derivates on mammals is antiatherogenic. But there were no publication about connection between azole derivates effect on hyperlipidemia and expression of genes with antiatherogenic effects. In our work we used triton model of hyperlipodemia on rats to analyze the effect of carmizole injection on the expression of the main antiatherogenic genes and their regulators Apo A-I, HDL, LDL. We had four groups of rats: intact control group, triton control group, phenophibrate group and carmizole group. During a seven days we gave a per oral injections of carmizole for the carmizole group, phenophibrate (as a comparison drug) for phenophibrate group and 1% starch solution for triton control group. Liver tissue samples were used for RNA extraction and following RT-PCR (Real Time PCR) with primers for Apo A-I mRNA sequence. We have found, that Apo A-I mRNA level decreased in the triton control group to 17%, but restored up to 89% in the carmizole group. Carmizole derivate drug works like stimulator of Apo A-I gene expression. That increasing of the expression of antiatherogenic protein gene could me the base of the antiatherogenic effect of the carmizole derivate.