Proteolytic cleavage of pertussis toxin S1 subunit is not essential for its activity in mammalian cells

Background  

Pertussis toxin (PT) is an exotoxin virulence factor produced by Bordetella pertussis, the causative agent of whooping cough. PT consists of an active subunit (S1) that ADP-ribosylates the alpha subunit of several mammalian G proteins, and a B oligomer (S2–S5) that binds glycoconjugate receptors on cells. PT appears to enter cells by endocytosis, and retrograde transport through the Golgi apparatus may be important for its cytotoxicity. A previous study demonstrated that proteolytic processing of S1 occurs after PT enters mammalian cells. We sought to determine whether this proteolytic processing of S1 is necessary for PT cytotoxicity.     

Identification and expression analysis of microRNAs and targets in the biofuel crop sugarcane

Background  

MicroRNAs (miRNAs) are small regulatory RNAs, some of which are conserved in diverse plant genomes. Therefore, computational identification and further experimental validation of miRNAs from non-model organisms is both feasible and instrumental for addressing miRNA-based gene regulation and evolution. Sugarcane (Saccharum spp.) is an important biofuel crop with publicly available expressed sequence tag and genomic survey sequence databases, but little is known about miRNAs and their targets in this highly polyploid species.     

Effect of bradykinin and morphine on rat sensomotor cortex neurons]

As revealed in acute experiments on rats bradykinin applied microiontophoretically produced neuronal activation in the sensory-motor region of the rat brain cortex. Morphine applied iontophoretically prevented bradykinin effect. It is suggested that bradykinin interacts with opiate receptors in the cortical neurones.     

Delta-sleep-inducing peptide (DSIP) as a factor facilitating animals' resistance to acute emotional stress

Delta-sleep-inducing peptide (DSIP) effects on resistance to acute emotional stress induced by electric stimulation of the ventromedial hypothalamus and skin of immobilized rats have been investigated. On the basis of the pattern of cardiovascular reactions, three groups of rats were distinguished: resistant, adapted, and predisposed to the experimental emotional stress. It is shown that DSIP injections increase animals' resistance to acute emotional stress. DSIP also changes the vascular reactivity to episodic emotiogenic stimulations. It is revealed that, after DSIP application, the absence of vascular reactions to emotiogenic ventromedial hypothalamic and electro-skin stimulations significantly increased.     

Delta sleep-inducing peptide in the blood and hypothalamus of rats with various resistance to emotional stress

Enzyme immunoassay was used to study delta-sleep peptide content in blood and hypothalamus in rats of Wistar lines under acute emotional stress. It was found that the content of delta-sleep peptide in blood and hypothalamus of stable rats was higher as compared with rats predisposed to emotional stress. After 1.5-hour emotional stress the content of delta-sleep peptide increased in blood and hypothalamus both in stable rats and predisposed ones. After 3-hour stress there was an increase in delta-sleep peptide content in hypothalamus, and contrary to its decrease in blood in both stable and predisposed animals. It is supposed that delta-sleep peptide along with other oligopeptides is one of the factors determining individual animal resistance to emotional stress, which is supported by significant delta-sleep peptide increase in hypothalamus in stable rats.