Cellular coexistence of two high molecular subsets of eEF1B complex

AbstractThe elongation factor eEF1B involved in protein translation was found to contain two isoforms of the eEF1Bδ subunit in sea urchin eggs. The eEF1Bδ2 isoform differs from eEF1Bδ1 by a specific insert of 26 amino acids. Both isoforms are co-expressed in the cell and likely originate from a unique gene. The feature appears universal in metazoans as judged from in silico analysis in EST-databanks. The eEF1B components were co-immunoprecipitated by specific eEF1Bδ2 antibodies. Quantification of the proteins in immunoprecipitates and on immunoblots demonstrates that eEF1Bδ1 and eEF1Bδ2 proteins are present in two subsets of eEF1B complex. We discuss and propose a model for the different subsets of eEF1B complex concomitantly present in the cell

Purification, Cloning, Characterization and Essential Amino Acid Residues Analysis of a New iota-Carrageenase from Cellulophaga sp QY3

ι-Carrageenases belong to family 82 of glycoside hydrolases that degrade sulfated galactans in the red algae known as ι-carrageenans. The catalytic mechanism and some substrate-binding residues of family GH82 have been studied but the substrate recognition and binding mechanism of this family have not been fully elucidated. We report here the purification, cloning and characterization of a new ι-carrageenase CgiA_Ce from the marine bacterium Cellulophaga sp. QY3. CgiA_Ce was the most thermostable carrageenase described so far. It was most active at 50°C and pH 7.0 and retained more than 70% of the original activity after incubation at 50°C for 1 h at pH 7.0 or at pH 5.0–10.6 for 24 h. CgiA_Ce was an endo-type ι-carrageenase; it cleaved ι-carrageenan yielding neo-ι-carrabiose and neo-ι-carratetraose as the main end products, and neo-ι-carrahexaose was the minimum substrate. Sequence analysis and structure modeling showed that CgiA_Ce is indeed a new member of family GH82. Moreover, sequence analysis of ι-carrageenases revealed that the amino acid residues at subsites −1 and +1 were more conserved than those at other subsites. Site-directed mutagenesis followed by kinetic analysis identified three strictly conserved residues at subsites −1 and +1 of ι-carrageenases, G228, Y229 and R254 in CgiA_Ce, which played important roles for substrate binding. Furthermore, our results suggested that Y229 and R254 in CgiA_Ce interacted specifically with the sulfate groups of the sugar moieties located at subsites −1 and +1, shedding light on the mechanism of ι-carrageenan recognition in the family GH82

Influence of cirrhosis on outcomes of patients with advanced intrahepatic cholangiocarcinoma receiving chemotherapy

International audienceBackground: Cirrhosis is a risk factor for intrahepatic cholangiocarcinoma (iCC). However, its exact prevalence is uncertain and its impact on the management of advanced disease is not established.Methods: Retrospective analysis of patients treated with systemic chemotherapy for advanced iCC in the 1st-line setting at 2 tertiary cancer referral centres. Cirrhosis was diagnosed based on at least one element prior to any treatment: pathological diagnosis, baseline platelets <150 × 109/L, portal hypertension and/or dysmorphic liver on imaging.Results: In the cohort of patients (n = 287), 82 (28.6%) had cirrhosis (45 based on pathological diagnosis). Patients with cirrhosis experienced more grade 3/4 haematologic toxicity (44% vs 22%, respectively, P = 0.001), and more grade 3/4 non-haematologic toxicity (34% vs 14%, respectively, P = 0.001) than those without. The overall survival (OS) was significantly shorter in patients with cirrhosis: median 9.1 vs 13.1 months for those without (HR = 1.56 [95% CI: 1.19-2.05]); P = 0.002), confirmed on multivariable analysis (HR = 1.48 [95% CI: 1.04-2.60]; P = 0.028).Conclusion: Cirrhosis was relatively common in patients with advanced iCC and was associated with increased chemotherapy-induced toxicity and shorter OS. Formal assessment and consideration of cirrhosis in therapeutic management is recommended

Bostonia: The Boston University Alumni Magazine. Volume 9

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Fluropyrimidine single agent or doublet chemotherapy as second line treatment in advanced biliary tract cancer

Fluoropyrimidine (FP) plus platinum chemotherapy has been recently established as a second-line (L2) preferred option in advanced biliary tract cancer (aBTC) (ABC-06 phase III trial). However, the overall survival (OS) benefit was limited and comparison with FP monotherapy was not available. Our aim was to assess the OS of patients treated with a FP monotherapy compared to a doublet with irinotecan or platinum in L2. We performed a retrospective analysis of two large multicenter prospective cohorts: a French cohort (28 centers) and an Italian cohort (9 centers). All consecutive patients with aBTC receiving FP-based L2 after gemcitabine plus cisplatin/gemcitabine plus oxaliplatin L1 between 2003 and 2016 were included. A subgroup analysis according to performance status (PS) and an exploratory analysis according to platinum sensitivity in L1 were planned. In the French cohort (n = 351), no significant OS difference was observed between the FP monotherapy and doublet groups (median OS: 5.6 vs 6.8 months, P =.65). Stratification on Eastern Cooperative Oncology Group (ECOG) PS showed similar results in PS 0-1 and 2. Median OS was not different between FP monotherapy, platinum- and irinotecan-based doublets (5.6 vs 7.1 vs 6.7 months, P =.68). Similar findings were observed in the Italian cohort (n = 174) and in the sensitivity analysis in pooled cohorts (n = 525). No L2 regimen seemed superior over others in the platinum resistant/refractory or sensitive subgroups. Our results suggest that FP monotherapy is as active as FP doublets in aBTC in L2, regardless of the patient PS and country, and could be a therapeutic option in this setting

Shank2 Mutant Mice Display Hyperactivity Insensitive to Methylphenidate and Reduced Flexibility in Social Motivation, but Normal Social Recognition

Mouse models of autism can be used to study evolutionarily conserved mechanisms underlying behavioral abnormalities in social communication and repetitive behaviors. SHANK genes code for synaptic scaffolding proteins at excitatory synapses and mutations in all SHANK genes have been associated with autism. Here, we present three behavioral aspects of the mutant mice deleted for exon 16 in Shank2. First, we treated Shank2 mutant mice with methylphenidate to rescue the hyperactivity. Our failure to do so suggests that the hyperactivity displayed by Shank2 mutant mice is not related to the one displayed by the typical mouse models of hyperactivity, and might be more closely related to manic-like behaviors. Second, by testing the effect of group housing and social isolation on social interest, we highlighted that Shank2 mutant mice lack the typical flexibility to modulate social interest, in comparison with wild-type littermates. Finally, we established a new protocol to test for social recognition in a social context. We used this protocol to show that Shank2 mutant mice were able to discriminate familiar and unknown conspecifics in free interactions. Altogether, these studies shed some light on specific aspects of the behavioral defects displayed by the Shank2 mouse model. Such information could be used to orient therapeutic strategies and to design more specific tests to characterize the complex behavior of mouse models of autism

Agreement with the internal possessor in Chimane

The paper examines a type of clausal construction in Chimane (or Tsimane’, unclassified, Bolivia) in which possessors which are apparently internal to patient- or recipient-like possessive phrases can control object agreement on the verb. Various aspects of the construction point to an analysis in which the internal possessor is doubled by an external representation or ‘proxy’ in the clause which mediates the agreement relation between the possessor and the verb. The construction bears some resemblance to external possessor constructions, albeit with the added complication that the possessor itself remains internal to the possessive phrase while its argument function is borne by the external proxy. The paper examines features of the construction and contrasts it with similar or related phenomena which have been identified in other languages

The eEF1γ Subunit Contacts RNA Polymerase II and Binds Vimentin Promoter Region

Here, we show that the eukaryotic translation elongation factor 1 gamma (eEF1γ) physically interacts with the RNA polymerase II (pol II) core subunit 3 (RPB3), both in isolation and in the context of the holo-enzyme. Importantly, eEF1γ has been recently shown to bind Vimentin mRNA. By chromatin immunoprecipitation experiments, we demonstrate, for the first time, that eEF1γ is also physically present on the genomic locus corresponding to the promoter region of human Vimentin gene. The eEF1γ depletion causes the Vimentin protein to be incorrectly compartmentalised and to severely compromise cellular shape and mitochondria localisation. We demonstrate that eEF1γ partially colocalises with the mitochondrial marker Tom20 and that eEF1γ depletion increases mitochondrial superoxide generation as well as the total levels of carbonylated proteins. Finally, we hypothesise that eEF1γ, in addition to its role in translation elongation complex, is involved in regulating Vimentin gene by contacting both pol II and the Vimentin promoter region and then shuttling/nursing the Vimentin mRNA from its gene locus to its appropriate cellular compartment for translation