Yra1p and Sub2p are components of the TREX complex, which couples transcription elongation with nuclear export of mRNAs. Here, we report a genetic interaction between Yra1p and a conserved protein Sac3p, which previously was found to interact with Sub2p. In vivo , Sac3p forms a stable complex with Thp1p, which was reported to function in transcription elongation. In addition, Sac3p binds to the mRNA exporter Mex67p–Mtr2p and requires the nucleoporin Nup1p to dock at the nuclear side of the nuclear pore complex (NPC). Significantly, mutations in Sac3p or Thp1p lead to strong mRNA export defects. Taken together, our data suggest that the novel Sac3p–Thp1p complex functions by docking the mRNP to specific nucleoporins at the nuclear entrance of the NPC.
In vivo function of the molecular chaperone Hsp90 is ATP-dependent and requires the full-length protein. Our earlier studies predicted a second C-terminal ATP-binding site in Hsp90. By applying direct biochemical approaches, we mapped two ATP-binding sites and unveiled the C-terminal ATP-binding site as the first example of a cryptic chaperone nucleotide-binding site, which is opened by occupancy of the N-terminal site. We identified an N-terminal gamma-phosphate-binding motif in the middle domain of Hsp90 similar to other GHKL family members. This motif is adjacent to the phosphate-binding region of the C-terminal ATP-binding site. Whereas novobiocin disrupts both C- and N-terminal nucleotide binding, we found a selective C-terminal nucleotide competitor, cisplatin, that strengthens the Hsp90-Hsp70 complex leaving the Hsp90-p23 complex intact. Cisplatin may provide a pharmacological tool to dissect C- and N-terminal nucleotide binding of Hsp90. A model is proposed on the interactions of the two nucleotide-binding domains and the charged region of Hsp90.
Objective Resective surgery is effective in treating drug-resistant focal epilepsy, but it remains unclear whether improved diagnostics influence postsurgical outcomes. Here, we compared practice and outcomes over 2 periods 15 years apart. Methods Sixteen European centers retrospectively identified 2 cohorts of children and adults who underwent epilepsy surgery in the period of 1997 to 1998 (n = 562) or 2012 to 2013 (n = 736). Data collected included patient (sex, age) and disease (duration, localization and diagnosis) characteristics, type of surgery, histopathology, Engel postsurgical outcome, and complications, as well as imaging and electrophysiologic tests performed for each case. Postsurgical outcome predictors were included in a multivariate logistic regression to assess the strength of date of surgery as an independent predictor. Results Over time, the number of operated cases per center increased from a median of 31 to 50 per 2-year period (p = 0.02). Mean disease duration at surgery decreased by 5.2 years (p < 0.001). Overall seizure freedom (Engel class 1) increased from 66.7% to 70.9% (adjusted p = 0.04), despite an increase in complex surgeries (extratemporal and/or MRI negative). Surgeries performed during the later period were 1.34 times (adjusted odds ratio; 95% confidence interval 1.02–1.77) more likely to yield a favorable outcome (Engel class I) than earlier surgeries, and improvement was more marked in extratemporal and MRI-negative temporal epilepsy. The rate of persistent neurologic complications remained stable (4.6%–5.3%, p = 0.7). Conclusion Improvements in European epilepsy surgery over time are modest but significant, including higher surgical volume, shorter disease duration, and improved postsurgical seizure outcomes. Early referral for evaluation is required to continue on this encouraging trend.
Summary: Objective: To pool observational data on the routine use of perampanel to obtain information on real‐world outcomes and data in populations typically underrepresented in clinical trials.Methods: Individual‐level data of people with epilepsy treated with perampanel at 45 European centers were merged into a single dataset. Prespecified outcomes were: 1‐year retention rate, 1‐year seizure freedom rate (duration ≥6 months), and incidence of treatment‐emergent adverse events (TEAEs). In addition, relationships were explored with logistic regression analyses.Results: The full analysis set comprised 2396 people: 95% had focal seizures; median epilepsy duration was 27 years; median number of concomitant antiepileptic drugs (AEDs) was 2; and median prior AEDs was 6. One‐year retention rate was 48% (1117/2332; 95% confidence interval [CI] 46‐50%), and 1‐year seizure‐free rate (≥6‐month duration) was 9.2% (74/803; 95% CI 7‐11%). Median treatment duration was 11.3 months (1832 patient‐years); median dose was 8 mg. In 388 individuals with available data at 3, 6, and 12 months, responder rates were 42%, 46%, and 39%, respectively. During the first year, TEAEs were reported in 68% of participants (1317/1497; 95% CI 66‐70%). Logistic regression found higher age at perampanel initiation was associated with higher seizure‐free rate, and higher number of prior AEDs with lower seizure‐free rate and lower rates of somatic TEAEs. In 135 individuals aged ≥65 years, 1‐year retention rate was 48% and seizure‐free rate was 28%.Significance: Across a large, treatment‐resistant population, add‐on perampanel was retained for ≥1 year by 48% of individuals, and 9% were seizure‐free for ≥6 months. TEAEs were in line with previous reports in routine clinical use, and less frequent than in the clinical trial setting. No new or unexpected TEAEs were seen. Despite the limitations of observational studies, our data indicate that some individuals may derive a marked benefit from the use of perampanel.