We explored how a simple retrovirus, Mason-Pfizer monkey virus (M-PMV) to facilitate its replication process, utilizes DHX15, a cellular RNA helicase, typically engaged in RNA processing. Through advanced genetic engineering techniques, we showed that M-PMV recruits DHX15 by mimicking cellular mechanisms, relocating it from the nucleus to the cytoplasm to aid in viral assembly. This interaction is essential for the correct packaging of the viral genome and critical for its infectivity. Our findings offer unique insights into the mechanisms of viral manipulation of host cellular processes, highlighting a sophisticated strategy that viruses employ to leverage cellular machinery for their replication. This study adds valuable knowledge to the understanding of viral-host interactions but also suggests a common evolutionary history between cellular processes and viral mechanisms. This finding opens a unique perspective on the export mechanism of intron-retaining mRNAs in the packaging of viral genetic information and potentially develop ways to stop it.

• MeSH
• buněčné jádro metabolismus   virologie   MeSH
• DEAD-box RNA-helikasy metabolismus   genetika   MeSH
• genom virový MeSH
• HEK293 buňky MeSH
• lidé MeSH
• Masonův-Pfizerův opičí virus * genetika   metabolismus   fyziologie   MeSH
• replikace viru genetika   fyziologie   MeSH
• RNA virová * metabolismus   genetika   MeSH
• RNA-helikasy metabolismus   genetika   MeSH
• sestavení viru * genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Mason-Pfizer monkey virus (M-PMV), like some other betaretroviruses, encodes a G-patch domain (GPD). This glycine-rich domain, which has been predicted to be an RNA binding module, is invariably localized at the 3' end of the pro gene upstream of the pro-pol ribosomal frameshift sequence of genomic RNAs of betaretroviruses. Following two ribosomal frameshift events and the translation of viral mRNA, the GPD is present in both Gag-Pro and Gag-Pro-Pol polyproteins. During the maturation of the Gag-Pro polyprotein, the GPD transiently remains a C-terminal part of the protease (PR), from which it is then detached by PR itself. The destiny of the Gag-Pro-Pol-encoded GPD remains to be determined. The function of the GPD in the retroviral life cycle is unknown. To elucidate the role of the GPD in the M-PMV replication cycle, alanine-scanning mutational analysis of its most highly conserved residues was performed. A series of individual mutations as well as the deletion of the entire GPD had no effect on M-PMV assembly, polyprotein processing, and RNA incorporation. However, a reduction of the reverse transcriptase (RT) activity, resulting in a drop in M-PMV infectivity, was determined for all GPD mutants. Immunoprecipitation experiments suggested that the GPD is a part of RT and participates in its function. These data indicate that the M-PMV GPD functions as a part of reverse transcriptase rather than protease.

• MeSH
• buněčné linie MeSH
• lidé MeSH
• Masonův-Pfizerův opičí virus chemie   enzymologie   genetika   MeSH
• polyproteiny chemie   genetika   metabolismus   MeSH
• reverzní transkriptasa chemie   genetika   metabolismus   MeSH
• terciární struktura proteinů MeSH
• virové proteiny chemie   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

GABAB receptors are the G-protein coupled receptors for the main inhibitory neurotransmitter in the brain, GABA. GABAB receptors were shown to associate with homo-oligomers of auxiliary KCTD8, KCTD12, KCTD12b, and KCTD16 subunits (named after their T1 K(+)-channel tetramerization domain) that regulate G-protein signaling of the receptor. Here we provide evidence that GABAB receptors also associate with hetero-oligomers of KCTD subunits. Coimmunoprecipitation experiments indicate that two-thirds of the KCTD16 proteins in the hippocampus of adult mice associate with KCTD12. We show that the KCTD proteins hetero-oligomerize through self-interacting T1 and H1 homology domains. Bioluminescence resonance energy transfer measurements in live cells reveal that KCTD12/KCTD16 hetero-oligomers associate with both the receptor and the G-protein. Electrophysiological experiments demonstrate that KCTD12/KCTD16 hetero-oligomers impart unique kinetic properties on G-protein-activated Kir3 currents. During prolonged receptor activation (one min) KCTD12/KCTD16 hetero-oligomers produce moderately desensitizing fast deactivating K(+) currents, whereas KCTD12 and KCTD16 homo-oligomers produce strongly desensitizing fast deactivating currents and nondesensitizing slowly deactivating currents, respectively. During short activation (2 s) KCTD12/KCTD16 hetero-oligomers produce nondesensitizing slowly deactivating currents. Electrophysiological recordings from hippocampal neurons of KCTD knock-out mice are consistent with these findings and indicate that KCTD12/KCTD16 hetero-oligomers increase the duration of slow IPSCs. In summary, our data demonstrate that simultaneous assembly of distinct KCTDs at the receptor increases the molecular and functional repertoire of native GABAB receptors and modulates physiologically induced K(+) current responses in the hippocampus. SIGNIFICANCE STATEMENT: The KCTD proteins 8, 12, and 16 are auxiliary subunits of GABAB receptors that differentially regulate G-protein signaling of the receptor. The KCTD proteins are generally assumed to function as homo-oligomers. Here we show that the KCTD proteins also assemble hetero-oligomers in all possible dual combinations. Experiments in live cells demonstrate that KCTD hetero-oligomers form at least tetramers and that these tetramers directly interact with the receptor and the G-protein. KCTD12/KCTD16 hetero-oligomers impart unique kinetic properties to GABAB receptor-induced Kir3 currents in heterologous cells. KCTD12/KCTD16 hetero-oligomers are abundant in the hippocampus, where they prolong the duration of slow IPSCs in pyramidal cells. Our data therefore support that KCTD hetero-oligomers modulate physiologically induced K(+) current responses in the brain.

• MeSH
• CHO buňky MeSH
• Cricetulus MeSH
• draslíkové kanály genetika   metabolismus   MeSH
• elektrofyziologické jevy genetika   MeSH
• excitační postsynaptické potenciály genetika   MeSH
• kinetika MeSH
• křečci praví MeSH
• metoda terčíkového zámku MeSH
• mozek - chemie genetika   MeSH
• myši knockoutované MeSH
• myši MeSH
• receptory GABA-B genetika   metabolismus   MeSH
• receptory KIR metabolismus   MeSH
• receptory spřažené s G-proteiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

GABAB receptors assemble from GABAB1 and GABAB2 subunits. GABAB2 additionally associates with auxiliary KCTD subunits (named after their K(+) channel tetramerization-domain). GABAB receptors couple to heterotrimeric G-proteins and activate inwardly-rectifying K(+) channels through the βγ subunits released from the G-protein. Receptor-activated K(+) currents desensitize in the sustained presence of agonist to avoid excessive effects on neuronal activity. Desensitization of K(+) currents integrates distinct mechanistic underpinnings. GABAB receptor activity reduces protein kinase-A activity, which reduces phosphorylation of serine-892 in GABAB2 and promotes receptor degradation. This form of desensitization operates on the time scale of several minutes to hours. A faster form of desensitization is induced by the auxiliary subunit KCTD12, which interferes with channel activation by binding to the G-protein βγ subunits. Here we show that the two mechanisms of desensitization influence each other. Serine-892 phosphorylation in heterologous cells rearranges KCTD12 at the receptor and slows KCTD12-induced desensitization. Likewise, protein kinase-A activation in hippocampal neurons slows fast desensitization of GABAB receptor-activated K(+) currents while protein kinase-A inhibition accelerates fast desensitization. Protein kinase-A fails to regulate fast desensitization in KCTD12 knock-out mice or knock-in mice with a serine-892 to alanine mutation, thus demonstrating that serine-892 phosphorylation regulates KCTD12-induced desensitization in vivo. Fast current desensitization is accelerated in hippocampal neurons carrying the serine-892 to alanine mutation, showing that tonic serine-892 phosphorylation normally limits KCTD12-induced desensitization. Tonic serine-892 phosphorylation is in turn promoted by assembly of receptors with KCTD12. This cross-regulation of serine-892 phosphorylation and KCTD12 activity sharpens the response during repeated receptor activation.

• MeSH
• alanin genetika   metabolismus   MeSH
• CHO buňky MeSH
• Cricetulus MeSH
• draslík metabolismus   MeSH
• fosforylace MeSH
• hipokampus cytologie   metabolismus   MeSH
• kultivované buňky MeSH
• metoda terčíkového zámku MeSH
• myši knockoutované MeSH
• myši MeSH
• neurony metabolismus   MeSH
• proteinkinasy závislé na cyklickém AMP metabolismus   MeSH
• proteiny vázající GTP metabolismus   MeSH
• receptory GABA-B genetika   metabolismus   MeSH
• receptory GABA genetika   metabolismus   MeSH
• serin genetika   metabolismus   MeSH
• substituce aminokyselin MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Protease-activated receptors 2 (PAR2) and transient receptor potential vanilloid 1 (TRPV1) receptors in the peripheral nerve endings are implicated in the development of increased sensitivity to mechanical and thermal stimuli, especially during inflammatory states. Both PAR2 and TRPV1 receptors are co-expressed in nociceptive dorsal root ganglion (DRG) neurons on their peripheral endings and also on presynaptic endings in the spinal cord dorsal horn. However, the modulation of nociceptive synaptic transmission in the superficial dorsal horn after activation of PAR2 and their functional coupling with TRPV1 is not clear. To investigate the role of spinal PAR2 activation on nociceptive modulation, intrathecal drug application was used in behavioural experiments and patch-clamp recordings of spontaneous, miniature and dorsal root stimulation-evoked excitatory postsynaptic currents (sEPSCs, mEPSCs, eEPSCs) were performed on superficial dorsal horn neurons in acute rat spinal cord slices. Intrathecal application of PAR2 activating peptide SLIGKV-NH2 induced thermal hyperalgesia, which was prevented by pretreatment with TRPV1 antagonist SB 366791 and was reduced by protein kinases inhibitor staurosporine. Patch-clamp experiments revealed robust decrease of mEPSC frequency (62.8 ± 4.9%), increase of sEPSC frequency (127.0 ± 5.9%) and eEPSC amplitude (126.9 ± 12.0%) in dorsal horn neurons after acute SLIGKV-NH2 application. All these EPSC changes, induced by PAR2 activation, were prevented by SB 366791 and staurosporine pretreatment. Our results demonstrate an important role of spinal PAR2 receptors in modulation of nociceptive transmission in the spinal cord dorsal horn at least partially mediated by activation of presynaptic TRPV1 receptors. The functional coupling between the PAR2 and TRPV1 receptors on the central branches of DRG neurons may be important especially during different pathological states when it may enhance pain perception.

• MeSH
• alergie metabolismus   patologie   MeSH
• anilidy farmakologie   MeSH
• buňky zadních rohů míšních účinky léků   fyziologie   MeSH
• chování zvířat účinky léků   MeSH
• cinnamáty farmakologie   MeSH
• excitační postsynaptické potenciály účinky léků   MeSH
• hyperalgezie etiologie   prevence a kontrola   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• kationtové kanály TRPV antagonisté a inhibitory   metabolismus   MeSH
• krysa rodu rattus MeSH
• metoda terčíkového zámku MeSH
• mícha metabolismus   MeSH
• nervový přenos fyziologie   MeSH
• oligopeptidy farmakologie   MeSH
• potkani Wistar MeSH
• receptor PAR-2 agonisté   metabolismus   MeSH
• staurosporin farmakologie   MeSH
• techniky in vitro MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

D6 is a promoter/enhancer of the mDach1 gene that is involved in the development of the neocortex and hippocampus. It is expressed by proliferating neural stem/progenitor cells (NSPCs) of the cortex at early stages of neurogenesis. The differentiation potential of NSPCs isolated from embryonic day 12 mouse embryos, in which the expression of green fluorescent protein (GFP) is driven by the D6 promoter/enhancer, has been studied in vitro and after transplantation into the intact adult rat brain as well as into the site of a photochemical lesion. The electrophysiological properties of D6/GFP-derived cells were studied using the whole-cell patch-clamp technique, and immunohistochemical analyses were carried out. D6/GFP-derived neurospheres expressed markers of radial glia and gave rise predominantly to immature neurons and GFAP-positive cells during in vitro differentiation. One week after transplantation into the intact brain or into the site of a photochemical lesion, transplanted cells expressed only neuronal markers. D6/GFP-derived neurons were characterised by the expression of tetrodotoxin-sensitive Na(+)-currents and K (A)- and K (DR) currents sensitive to 4-aminopyridine. They were able to fire repetitive action potentials and responded to the application of GABA. Our results indicate that after transplantation into the site of a photochemical lesion, D6/GFP-derived NSPCs survive and differentiate into neurons, and their membrane properties are comparable to those transplanted into the non-injured cortex. Therefore, region-specific D6/GFP-derived NSPCs represent a promising tool for studying neurogenesis and cell replacement in a damaged cellular environment.

• MeSH
• bikukulin metabolismus   MeSH
• biologické markery metabolismus   MeSH
• blokátory draslíkových kanálů metabolismus   MeSH
• buněčná diferenciace fyziologie   MeSH
• embryo savčí anatomie a histologie   fyziologie   MeSH
• GABA antagonisté metabolismus   MeSH
• GABA metabolismus   MeSH
• kmenové buňky cytologie   fyziologie   MeSH
• krysa rodu rattus MeSH
• metoda terčíkového zámku MeSH
• myši MeSH
• neurony cytologie   fyziologie   MeSH
• promotorové oblasti (genetika) MeSH
• rekombinantní fúzní proteiny genetika   metabolismus   MeSH
• telencefalon cytologie   patologie   fyziologie   MeSH
• transplantace kmenových buněk MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The Slack (KCNT1) gene encodes sodium-activated potassium channels that are abundantly expressed in the central nervous system. Human mutations alter the function of Slack channels, resulting in epilepsy and intellectual disability. Most of the disease-causing mutations are located in the extended cytoplasmic C-terminus of Slack channels and result in increased Slack current. Previous experiments have shown that the C-terminus of Slack channels binds a number of cytoplasmic signaling proteins. One of these is Phactr1, an actin-binding protein that recruits protein phosphatase 1 (PP1) to certain phosphoprotein substrates. Using co-immunoprecipitation, we found that Phactr1 is required to link the channels to actin. Using patch clamp recordings, we found that co-expression of Phactr1 with wild-type Slack channels reduces the current amplitude but has no effect on Slack channels in which a conserved PKC phosphorylation site (S407) that regulates the current amplitude has been mutated. Furthermore, a Phactr1 mutant that disrupts the binding of PP1 but not that of actin fails to alter Slack currents. Our data suggest that Phactr1 regulates the Slack by linking PP1 to the channel. Targeting Slack-Phactr1 interactions may therefore be helpful in developing the novel therapies for brain disorders associated with the malfunction of Slack channels.

• MeSH
• aktiny metabolismus   MeSH
• buněčné linie MeSH
• draslíkové kanály aktivované sodíkem metabolismus   MeSH
• HEK293 buňky MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• membránové potenciály fyziologie   MeSH
• metoda terčíkového zámku metody   MeSH
• mutace genetika   MeSH
• myši MeSH
• neurony metabolismus   MeSH
• proteinfosfatasa 1 metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Cíl práce: Zhodnocení přínosu transdermální formy kombinované hormonální antikoncepce, uvolňujídenně 150 g norelgestrominu a 20 g ethinylestradiolu.Typ práce: Souhrnný přehled.Název a sídlo pracoviště: Gynekologicko-porodnická klinika VFN a 1. LF UK v Praze.Výsledky: Transdermální antikoncepční systém má příznivý farmakokinetický profil, účinné koncentracejsou v průběhu dne stabilní (narozdíl od

Objective: To present a review of a novel transdermal contraceptive patch containing norelgestromin(150 g/d) and ethinylestradiol (20 g/d).Design: Review article.Setting: Department of Gynecology and Obstetric, 1st Medical Faculty and General Faculty Hospital,Prague.Results: The contraceptive patch exhibits favourable pharmakokinetic profile, maintaining efficaciousserum hormone concentrations u

• Klíčová slova
• EVRA,
• MeSH
• antikoncepce metody   využití   MeSH
• aplikace kožní MeSH
• ethinylestradiol aplikace a dávkování   MeSH
• kombinace léků ethinylestradiol a norgestrel aplikace a dávkování   MeSH
• norgestrel aplikace a dávkování   MeSH
• Publikační typ
• přehledy MeSH

Orexins (orexin A and B) are initially known to be a hypothalamic peptide critical for feeding and normal wakefulness. In addition, emerging evidence from behavioral tests suggests that orexins are also involved in the regulation of nociceptive processing, suggesting a novel potential therapeutic approach for pain treatment. Both spinal and supraspinal mechanisms appear to contribute to the role of orexin in nociception. In the spinal cord, dorsal root ganglion (DRG) neurons are primary afferent neurons that transmit peripheral stimuli to the pain-processing areas. Morphological results show that both orexin A and orexin- 1 receptor are distributed in DRG neurons. Moreover, by using whole-cell patch-clamp recordings and calcium imaging measurements we found that orexin A induced excitability and intracellular calcium concentration elevation in the isolated rat DRG neurons, which was mainly dependent on the activation of spinal orexin-1 receptor. Based on these findings, we propose a hypothesis that the direct effect of orexin A on DRG neurons would represent a possible mechanism for the orexinergic modulation of spinal nociceptive transmission.

• Klíčová slova
• Orexins, Nociceptive transmission, Dorsal root ganglion neurons, Spinal cord, Orexin-1 receptor, Patch clamp, Calcium imaging,
• MeSH
• akční potenciály MeSH
• benzoxazoly farmakologie   MeSH
• bolest metabolismus   MeSH
• intracelulární signální peptidy a proteiny metabolismus   MeSH
• krysa rodu rattus MeSH
• močovina analogy a deriváty   farmakologie   MeSH
• nervový přenos účinky léků   MeSH
• neurony metabolismus   účinky léků   MeSH
• neuropeptidy metabolismus   MeSH
• potkani Sprague-Dawley MeSH
• receptory neuropeptidů antagonisté a inhibitory   metabolismus   MeSH
• receptory spřažené s G-proteiny antagonisté a inhibitory   metabolismus   MeSH
• spinální ganglia cytologie   metabolismus   účinky léků   MeSH
• vápníková signalizace MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

We identified breast cancer-associated protein (BCA3) as a novel binding partner of Mason-Pfizer monkey virus (MPMV) protease (PR). The interaction was confirmed by co-immunoprecipitation and immunocolocalization of MPMV PR and BCA3. Full-length but not C-terminally truncated BCA3 was incorporated into MPMV virions. We ruled out the potential role of the G-patch domain, a glycine-rich domain located at the C terminus of MPMV PR, in BCA3 interaction and virion incorporation. Expression of BCA3 did not affect MPMV particle release and proteolytic processing; however, it slightly increased MPMV infectivity.

• MeSH
• adaptorové proteiny signální transdukční chemie   genetika   metabolismus   MeSH
• druhová specificita MeSH
• endopeptidasy chemie   genetika   metabolismus   MeSH
• HEK293 buňky MeSH
• interakční proteinové domény a motivy MeSH
• jaderné proteiny chemie   genetika   metabolismus   MeSH
• lidé MeSH
• Masonův-Pfizerův opičí virus enzymologie   genetika   MeSH
• molekulární sekvence - údaje MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH