Synergistic action of actinoporin isoforms from the same sea anemone species assembled into functionally active heteropores

Among the toxic polypeptides secreted in the venom of sea anemones, actinoporins are pore forming toxins whose toxic activity relies on the formation of oligomeric pores within biological membranes. Intriguingly, actinoporins appear as multigene families which give rise to many protein isoforms in the same individual displaying high sequence identities but large functional differences. However, the evolutionary advantage of producing such similar isotoxins is not fully understood. Here, using sticholysins I and II (StnI and StnII) from the sea anemone Stichodactyla helianthus, it is shown that actinoporin isoforms can potentiate each other’s activity. Through hemolysis and calcein releasing assays, it is revealed that mixtures of StnI and StnII are more lytic than equivalent preparations of the corresponding isolated isoforms. It is then proposed that this synergy is due to the assembly of heteropores since (i) StnI and StnII can be chemically cross-linked at the membrane and (ii) the affinity of sticholysin mixtures for the membrane is increased with respect to any of them acting in isolation, as revealed by isothermal titration calorimetry experiments. These results help to understand the multigene nature of actinoporins and may be extended to other families of toxins that require oligomerization to exert toxicity.

Synergistic Action of Actinoporin Isoforms from the Same Sea Anemone Species Assembled into Functionally Active Heteropores

Among the toxic polypeptides secreted in the venom of sea anemones, actinoporins are the pore-forming toxins whose toxic activity relies on the formation of oligomeric pores within biological membranes. Intriguingly, actinoporins appear as multigene families that give rise to many protein isoforms in the same individual displaying high sequence identities but large functional differences. However, the evolutionary advantage of producing such similar isotoxins is not fully understood. Here,using sticholysins I and II (StnI and StnII) from the sea anemone Stichodactyla helianthus, it is shown that actinoporin isoforms can potentiate each other’s activity. Through hemolysis and calcein releasing assays, it is revealed that mixtures of StnI and StnII are more lytic than equivalent preparations of the corresponding isolated isoforms. It is then proposed that this synergy is due to the assembly of heteropores because (i) StnI and StnII can be chemically cross-linked at the membrane and (ii) the affinity of sticholysin mixtures for the membrane is increased with respect to any of them acting in isolation, as revealed by isothermal titration calorimetry experiments. These results help us understand the multigene nature of actinoporins and may be extended to other families of toxins that require oligomerization to exert toxicity.

Extractive text summarization: can we use the same techniques for any text?

In this paper we address two issues. The first one analyzes whether the performance of a text summarization method depends on the topic of a document. The second one is concerned with how certain linguistic properties of a text may affect the performance of a number of automatic text summarization methods. For this we consider semantic analysis methods, such as textual entailment and anaphora resolution, and we study how they are related to proper noun, pronoun and noun ratios calculated over original documents that are grouped into related topics. Given the obtained results, we can conclude that although our first hypothesis is not supported, since it has been found no evident relationship between the topic of a document and the performance of the methods employed, adapting summarization systems to the linguistic properties of input documents benefits the process of summarization.

An act for granting to His Majesty the sum of fifty-five thousand pounds, and for striking the same in bills of credit, in the manner herein after directed..., 1764

Contains an act for collection of taxes to pay the debt by establishing a set fee of fifteen shillings per head and household.

First Account of Administration on C. Gannett's Estate & Papers relating to the same, [1818]

Long paper notebook with a handwritten inventory of Gannett's estate arranged by house location with price estimates. The inventory appears to correspond with the "Sales at auction" document. The verso of the last page contains the note: "Inventory of Personal Estate (copy)."

Early Parliamentary Elections in Macedonia: More of the same or new beginnings? CEPS Commentaries, 21 March 2014

There is no doubt that the prospect of EU accession has had a major impact in promoting much-needed reforms and building stable institutions in the countries of former Yugoslavia. Yet, as reflected in all the internationally recognised indicators, the goal of achieving effective democracy throughout the region remains very much a 'work in progress', especially in Macedonia. In this Commentary, Erwan Fouéré considers whether the main governing party in Macedonia will change its behaviour to enable the country to move forward.

Sharing the same vision – The cornerstone of a new industrial policy for Europe. EPC Discussion Paper, 20 March 2014

Claire Dhéret argues in this discussion paper that Member States should seize the opportunity offered by the 2014 March European Council to pave the way for an EU industrial policy providing the industry with what it needs most: an unambiguous and well-defined strategic plan for the decades to come. To this end, the author set the contours of three possible policy scenarios for the future of EU industrial policy in view to fostering a debate about what form a coherent strategic framework should take.