A new approach, graph-grammars, to encode RNA tertiary structure patterns is introduced and exemplified with the classical sarcin-ricin motif. The sarcin-ricin motif is found in the stem of the crucial ribosomal loop E (also referred to as the sarcin-ricin loop), which is sensitive to the alpha-sarcin and ricin toxins. Here, we generate a graph-grammar for the sarcin-ricin motif and apply it to...

Ricin is a type II ribosome-inactivating protein (RIP) that depurinates A4324 at the sarcin-ricin loop of 28 S ribosomal RNA (rRNA), thus inactivating the ribosome by preventing elongation factors from binding to the GTPase activation centre. Recent studies have disclosed that the conserved C-terminal domain (CTD) of eukaryotic ribosomal P stalk proteins is involved in the process that RIPs tar...

Ključne riječi: osteoartritis, patofiziologija, sinovitis, hrskavica, starenje, mehanički stres Sažetak Osteoartritis je poremećaj na razini organa. Zahvaća sve strukture zgloba. Biomehanički i genetski čimbenici igraju važnu ulogu u nastanku i napredovanju osteoartritisa, dok je upala važna u progresiji bolesti i degradaciji hrskavice uzrokujući bol, oteklinu i zakočenost zgloba. Novije spozna...

Fluoxetine is a commonly prescribed antidepressant compound. Its action is primarily attributed to selective inhibition of the reuptake of serotonin (5-hydroxytryptamine) in the central nervous system. Although this group of antidepressant drugs is generally believed to cause fewer proarrhythmic side effects compared with tricyclic antidepressants, serious concerns have been raised by case repo...

AMPA/kainate (KA) receptors mediate a component of ganglion cell excitatory postsynaptic currents (EPSCs). We investigated whether desensitization at these receptors contribute to the shape of transient EPSCs in ON-OFF ganglion cells. Whole-cell, voltage-clamp recordings were made from ganglion cells in the retinal slice or in isolation. EPSCs were evoked by either stimulating the slice with li...

The Janus-faced atracotoxins are a unique family of excitatory peptide toxins that contain a rare vicinal disulfide bridge. Although lethal to a wide range of invertebrates, their molecular target has remained enigmatic for almost a decade. We demonstrate here that these toxins are selective, high-affinity blockers of invertebrate Ca(2+)-activated K(+) (K(Ca)) channels. Janus-faced atracotoxin ...

In addition to increasing the conductance to sodium, light reduces the maintained voltage-dependent potassium current (iK) in Limulus ventral photoreceptors. We have investigated the mechanism underlying this long-lasting decrease in ik. Intracellular injection of calcium produced a similar reduction of the voltage-dependent outward current. This reduction was not due to an activation of the vo...

We examined the dopamine (DA) modulation of calcium currents (ICa) that could contribute to the plasticity of the pyloric network in the lobster stomatogastric ganglion. Pyloric somata were voltage-clamped under conditions designed to block voltage-gated Na+, K+, and H currents. Depolarizing steps from -60 mV generated voltage-dependent, inward currents that appeared to originate in electrotoni...

ATP increased the cytosolic Ca(2+) concentration ([Ca](i)) in nucleus accumbens neurons acutely dissociated from rat brain. The ATP response was dependent on external Ca(2+) and Na(+), and was blocked by voltage-dependent Ca(2+) channel blockers. The results suggest that the ATP-induced depolarization increases Ca(2+) influx resulting in the increase in [Ca](i).

In addition to their ionotropic role, neuronal nicotinic acetylcholine receptors (nAChRs) can influence second messenger levels, transmitter release and gene transcription. In this study, we show that nAChRs in an insect CNS control cGMP levels by coupling to NO production. In conditions that inhibit spiking, nicotine induced cGMP synthesis. This increase in cGMP was blocked by nicotinic antago...