A novel membrane structure called CUPS is assembled during the secretion of unconventional cargo such as Acb1.

SummaryA short motif termed Plasmodium export element (PEXEL) or vacuolar targeting signal (VTS) characterizes Plasmodium proteins exported into the host cell. These proteins mediate host cell modifications essential for parasite survival and virulence. However, several PEXEL-negative exported proteins indicate that the currently predicted malaria exportome is not complete and it is unknown whether and how these proteins relate to PEXEL-positive export. Here we show that the N-terminal 10 amino acids of the PEXEL-negative exported protein REX2 (ringexported protein 2) are necessary for its targeting and that a single-point mutation in this region abolishes export. Furthermore we show that the REX2 transmembrane domain is also essential for export and that together with the N-terminal region it is sufficient to promote export of another protein. An N-terminal region and the transmembrane domain of the unrelated PEXEL-negative exported protein SBP1 (skeleton-binding protein 1) can functionally replace the corresponding regions in REX2, suggesting that these sequence features are also present in other PEXEL-negative exported proteins. Similar to PEXEL proteins we find that REX2 is processed, but in contrast, detect no evidence for N-terminal acetylation.

Starvation triggers relocation of membranes of the secretory compartments and endosomes to create a compartment called CUPS, which may be involved in processing and secretion of proteins that cannot enter the ER–Golgi pathway.

Aorto-caval fistulas are an uncommon complication of infrarenal aortic aneurysms, being found in 0.22% to 6.04% of all cases. Operating on 1231 patients with abdominal aortic aneurysm in the last 30 years we saw 17 patients with an aortocaval fistula. While 5 patients showed an isolated fistula, 12 had an additional rupture of the aneurysm into the retroperitoneal space or the abdominal cavity. Only in four patients was the aorto-caval fistula diagnosed preoperatively. In 16 patients the fistula was closed from within the aorta. One patient needed ligation of the vena cava and the iliac veins. Mortality rate was 40% in the group with isolated fistula and 66.7% in the group with concomitant rupture. Aorto-caval fistula is a severe complication of abdominal aortic aneurysms, which may be fatal and demands early diagnosis and prompt treatment.

Africa, although not unique in this context, is a favourable environment for fungal infections, given the high burden of risk factors. An online survey was developed asking about laboratory infrastructure and antifungal drug availability. We received 40 responses (24•4% response rate) of 164 researchers contacted from 21 African countries. Only five institutions (12•5%) of 40 located in Cameroon, Kenya, Nigeria, Sudan, and Uganda potentially fulfilled the minimum laboratory requirements for European Confederation of Medical Mycology Excellence Centre blue status. Difficulties included low access to susceptibility testing for both yeasts and moulds (available in only 30% of institutions) and Aspergillus spp antigen detection (available in only 47•5% of institutions as an in-house or outsourced test), as well as access to mould-active antifungal drugs such as amphotericin B deoxycholate (available for 52•5% of institutions), itraconazole (52•5%), voriconazole (35•0%), and posaconazole (5•0%). United and targeted efforts are crucial to face the growing challenges in clinical mycology.

The intraerythrocytic developmental cycle of Plasmodium falciparum is completed with the release of up to 32 invasive daughter cells, the merozoites, into the blood stream. Before release, the final step of merozoite development is the assembly of the cortical pellicle, a multi-layered membrane structure. This unique apicomplexan feature includes the inner membrane complex (IMC) and the parasite's plasma membrane. A dynamic ring structure, referred to as the basal complex, is part of the IMC and helps to divide organelles and abscises in the maturing daughter cells. Here, we analyze the dynamics of the basal complex of P. falciparum. We report on a novel transmembrane protein of the basal complex termed BTP1, which is specific to the genus Plasmodium. It colocalizes with the known basal complex marker protein MORN1 and shows distinct dynamics as well as localization when compared to other IMC proteins during schizogony. Using a parasite plasma membrane marker cell line, we correlate dynamics of the basal complex with the acquisition of the maternal membrane. We show that plasma membrane invagination and IMC propagation are interlinked during the final steps of cell division.

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SummaryThe Golgi apparatus forms the heart of the secretory pathway in eukaryotic cells where proteins are modified, processed and sorted. The transport of proteins from the endoplasmic reticulum (ER) to the cis-side of the Golgi complex takes place at specialized ER subdomains known as transitional ER (tER). We used the Plasmodium falciparum orthologue of Sec13p to analyse tER organization. We show that the distribution of PfSec13p is restricted to defined areas of the ER membrane. These foci are juxtaposed to the Golgi apparatus and might represent tER sites. To further analyse cis-to trans-Golgi architecture, we generated a double transfectant parasite line that expresses the Golgi marker Golgi reassembly stacking protein (GRASP) as a green fluorescent protein fusion and the trans-Golgi marker Rab6 as a DsRed fusion protein. Our data demonstrate that Golgi multiplication is closely linked to tER multiplication, and that parasite maturation is accompanied by the spatial separation of the cis-and trans-face of this organelle.