University of Liverpool

About: University of Liverpool is a education organization based out in Liverpool, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 40406 authors who have published 94388 publications receiving 3188970 citations. The organization is also known as: Liverpool University & The University of Liverpool.

AMSH is an endosome-associated ubiquitin isopeptidase

Abstract: The JAMM (JAB1/MPN/Mov34 metalloenzyme) motif has been proposed to provide the active site for isopeptidase activity associated with the Rpn11/POH1 subunit of the 19S-proteasome and the Csn5-subunit of the signalosome. We have looked for similar activity in associated molecule with the SH3 domain of STAM (AMSH), a JAMM domain–containing protein that associates with the SH3-domain of STAM, a protein, which regulates receptor sorting at the endosome. We demonstrate isopeptidase activity against K48-linked tetraubiquitin and K63-linked polyubiquitin chains to generate di-ubiquitin and free ubiquitin, respectively. An inactivating mutation (D348A) in AMSH leads to accumulation of ubiquitin on endosomes and the concomitant stabilization of a ubiquitinated form of STAM, which requires an intact ubiquitin interaction motif (UIM) within STAM. Short interfering RNA knockdown of AMSH enhances the degradation rate of EGF receptor (EGFR) following acute stimulation and ubiquitinated EGFR provides a substrate for AMSH in vitro. We propose that AMSH is a deubiquitinating enzyme with functions at the endosome, which oppose the ubiquitin-dependent sorting of receptors to lysosomes.

Multiplexed absolute quantification for proteomics using concatenated signature peptides encoded by QconCAT genes

Abstract: An important area of proteomics involves the need for quantification, whether relative or absolute. Many methods now exist for relative quantification, but to support biomarker proteomics and systems biology, absolute quantification rather than relative quantification is required. Absolute quantification usually involves the concomitant mass spectrometric determination of signature proteotypic peptides and stable isotope-labeled analogs. However, the availability of standard labeled signature peptides in accurately known amounts is a limitation to the widespread adoption of this approach. We describe the design and synthesis of artificial QconCAT proteins that are concatamers of tryptic peptides for several proteins. This protocol details the methods for the design, expression, labeling, purification, characterization and use of the QconCATs in the absolute quantification of complex protein mixtures. The total time required to complete this protocol (from the receipt of the QconCAT expression plasmid to the absolute quantification of the set of proteins encoded by the QconCAT protein in an analyte sample) is approximately 29 d.

PD-1 + and follicular helper T cells are responsible for persistent HIV-1 transcription in treated aviremic individuals

Abstract: Matthieu Perreau and colleagues show that HIV-infected lymph node PD-1+ and follicular helper T cells account for the major source of replication-competent HIV-1 in individuals who have been treated with antiretroviral drugs.

Neural Correlates of Processing Valence and Arousal in Affective Words

Abstract: Psychological frameworks conceptualize emotion along 2 dimensions, "valence" and "arousal" Arousal invokes a single axis of intensity increasing from neutral to maximally arousing Valence can be described variously as a bipolar continuum, as independent positive and negative dimensions, or as hedonic value (distance from neutral) In this study, we used functional magnetic resonance imaging to characterize neural activity correlating with arousal and with distinct models of valence during presentation of affective word stimuli Our results extend observations in the chemosensory domain suggesting a double dissociation in which subregions of orbitofrontal cortex process valence, whereas amygdala preferentially processes arousal In addition, our data support the physiological validity of descriptions of valence along independent axes or as absolute distance from neutral but fail to support the validity of descriptions of valence along a bipolar continuum

The factor structure of "schizotypal' traits: a large replication study.

Abstract: The heterogeneity of schizotypal traits, suggested in previous research, was further investigated in a sample of subjects (N = 1095) administered a composite questionnaire consisting of a large number of published scales the majority of which were designed to measure psychotic characteristics. Factor analysis confirmed the four components previously indicated in our work with the same instrument; namely, ‘aberrant perceptions and beliefs’, ‘cognitive disorganization’, ‘introvertive anhedonia’ and ‘asocial behaviour’. This structure was maintained regardless of whether or not the analysis included scales from the Eysenck Personality Questionnaire, which might otherwise have been held to explain the variance. ‘Aberrant perceptions and beliefs’—reminiscent of the positive symptoms of schizophrenia was the strongest component; but, given the multidimensional nature of the data, together with the pattern of factor loadings and intercorrelations for the scales involved, it was concluded that the broader term ‘psychosis-proneness’ or ‘psychoticism’ (in a non-Eysenckian sense) might be a better descriptor of the clinical and personality domain sampled.