An evolutionary analysis of the reaction mechanisms of photosystem I reduction by cytochrome c(6) and plastocyanin

8 pages, 4 figures, 1 table.-- PMID: 11786337 [PubMed].-- Available online Nov 29, 2001.Photosystem I reduction by the soluble metalloproteins cytochrome c6 and plastocyanin, which are alternatively synthesized by some photosynthetic organisms depending on the relative availability of copper and iron, has been investigated in cyanobacteria, green algae and plants. The reaction mechanism is classified in three different types on the basis of the affinity of the membrane complex towards its electron donor protein. The role of electrostatic interactions in forming an intermediate transient complex, as well as the structural and functional similarities of cytochrome c6 and plastocyanin are analysed from an evolutionary point of view. The proposal made is that the heme protein was first “discovered” by nature, when iron was much more abundant on the Earth's surface, and replaced by plastocyanin when copper became available because of the oxidizing conditions of the new atmosphere.The research was supported by the European Union (Networks ERB-FMRX-CT98-0218 and HPRN-CT1999-00095), Spanish Ministry of Science and Technology (MCYT, Grant BMC2000-0444), and Andalusian Government (PAI, CVI-0198).Peer reviewe

Ultrasensitive Detection of Aβ42 Seeds in Cerebrospinal Fluid with a Nanopipette-Based Real-Time Fast Amyloid Seeding and Translocation Assay

International audienceIn this work, early-stage Aβ42 aggregates were detected using a real-time Fast Amyloid Seeding and Translocation (RT-FAST) assay. Specifically, Aβ42 monomers were incubated in buffer solution with and without preformed Aβ42 seeds in a quartz nanopipette coated with L-DOPA. Then, formed Aβ42 aggregates were analysed on flyby resistive pulse sensing at various incubation time points. Aβ42 aggregates were detected only in the sample with Aβ42 seeds after 180 minutes of incubation, giving an on/off readout of the presence of preformed seeds. Moreover, this RT-FAST assay could detect preformed seeds spiked in 4% cerebrospinal fluid/buffer solution. However, in this condition, the time to detect the aggregates and the nanopipette lifetime were increased. Analysis of Cy3-labelled Aβ42 monomer adsorption on a quartz substrate after L-DOPA coating by confocal fluorescence spectroscopy and molecular dynamic simulation showed the huge influence of Aβ42 adsorption on the aggregation process

Plasticity of Mature B Cells Between Follicular and Classic Hodgkin Lymphomas: A Series of 22 Cases Expanding the Spectrum of Transdifferentiation

International audienceFollicular lymphoma and classic Hodgkin lymphoma can be associated in composite and/or sequential lymphomas. Common IGH and BCL2 rearrangements have already been identified between both contingents of these entities, but mutation profiles have not yet been investigated. The main objective of this study was to analyze the transdifferentiation process that may occur between Hodgkin and follicular contingents in sequential and composite lymphomas to better characterize these entities. From 2004 to 2020, a retrospective multicentric study was performed, including 9 composite and 13 sequential lymphomas. Clinical data were retrospectively collected. Fluorescent in situ hybridization of BCL2 and BCL6 rearrangements, polymerase chain reaction of IGH and IGK rearrangements, next-generation sequencing of IGK rearrangement, and targeted next-generation sequencing (TNGS) on a panel of genes frequently mutated in lymphomas were performed on each contingent of composite and sequential lymphomas. For TNGS, each contingent was isolated by laser capture microdissection. Clinical presentation and evolution were more aggressive in sequential than composite lymphomas. By fluorescent in situ hybridization, common rearrangements of BCL6 and BCL2 were identified between both contingents. Similarly, a common clonal relationship was established by evaluating IGH and IGK rearrangement by polymerase chain reaction or next-generation sequencing. By TNGS, the same pathogenic variants were identified in both contingents in the following genes: CREBBP , KMT2D , BCL2 , EP300 , SF3B1 , SOCS1 , ARID1A , and BCOR . Specific pathogenic variants for each contingent were also identified: XPO1 for Hodgkin lymphoma contingent and FOXO1 , TNFRSF14 for follicular lymphoma contingent. This study reinforces the hypothesis of a transdifferentiation process between Hodgkin and follicular contingent of sequential/composite lymphomas

Reimagining Caribbean Time and Space: Speculative Fiction

peer reviewe

Dialogic Connections in Caribbean Literature and Visual Art

This essay discusses a series of links connecting Caribbean literature and the visual arts, paying particular attention to shared conceptual, critical preoccupations and visual vocabularies, as well as rhetorical strategies and aesthetic across art forms. It traces important stages in the ongoing dialogue between literature and art, including the foundational role of interdisciplinary movements, journals, art spaces and collaborations among writers and artists

Life writing, gender and Caribbean narrative 1970-2015: itinerant self-making in the postcolonial Caribbean

This chapter argues that contemporary Caribbean women exploit the malleability of life-writing as a genre in a variety of ways that recognize the precariousness of life-making and self-making in the post-plantation Caribbean. While each of the writers discussed here critically refashions life-narrative for their own distinct purposes, they frequently share an interest in filtering personal life experiences through familiar familial and regional histories to emphasize the imbrication of the personal and political. Narrating life-stories is presented in these texts as inextricably linked to the difficult cultural politics of self-making that is so powerfully evidenced from The History of Mary Prince through to the present. While life-writing remains haunted by the region’s violent history, Caribbean women writers continue to excavate that history in order to record, affirm, rescue, restore and celebrate self and life-making possibilities, however fragmented, precarious or itinerant

Digital Yards: Caribbean Writing on Social Media and Other Digital Platforms

The globalizing and interconnecting effects of technology in the twenty-first century have had a crucial impact on the development of Caribbean literary culture and the reconfiguration of its audiences. Caribbean writing and literary criticism are reaching wider audiences within the region and beyond via myriad digital platforms. Through social media, blogs, online journals, digital archives and the websites of publishing houses and festivals, the news and content of Caribbean literary work has become more accessible. Examining networks of ‘digital yards’, a concept built on Edward Kamau Brathwaite’s work, this essay surveys twenty-first century forms of digital Caribbean literary production while considering the continuities that remain between earlier forms of representation and Caribbean literary culture online today

The Caribbean and Britain

Although characterized by generational shifts in terms of articulating cultural affiliations and attachments to both the Caribbean and Britain, Caribbean British writing remains deeply marked by issues of un/belonging. This essay explores this embedded thematic across changing political contexts and reads the transitions in Caribbean British literature that have brought different revisionary perspectives on literary forms and languages, post-Windrush British history and the much deeper historical connections between the Caribbean presence and the UK. As well as contesting racism, these works articulate intersectional identities informed by class, gender and sexuality as it is experienced within and across the UK and the Caribbean. Given that contemporary Caribbean British literature is very much connected with Caribbean literature and that of the larger diaspora, this essay considers the modes of critical attention necessary to engage with its new forms and platforms