Three-dimensional model of the yeast genome with each chromosome colored differently.DR. MIRELA ANDRONESCU

1. New anti-malaria target
Many companies are trying to overcome malaria-drug resistance by targeting the malaria parasite’s plant-derived organelle, whose function is unknown but is for the parasite’s survival. Now researchers showed that the organelle produces isopentyle pyrophosphate (IPP), a precursor to a number of molecules vital for the parasite’s success during the blood phase. The study could have major implications for the development of anti-malarial drugs. E. Yeh, J.L Derisi, “Chemical rescue of malaria parasites lacking an apicoplast defines organelle function in blood-stage Plasmodium falciparum,” PLoS Biol, 9(8):e1001138, 2011. Free F1000 Evaluation

2. Yeast genome, now in 3-D
In this breakthrough paper, published in May 2010, researchers unveiled the most detailed three-dimensional model of a eukaryotic genome to date—that of Saccharomyces cerevisiae. The model was achieved through a novel method that coupled...

Z. Duan et al., “A three-dimensional model of the yeast genome,” Nature, 465:363-7, 2010.

3. Septin cages
When intracellular bacteria such as Shigella dysenteriae infect a cell, host proteins known as septins aggregate in thin fibers and corral the pathogen—both thwarting the bacteria’s motility and targeting it for autophagic degradation, researchers found. This is a novel role for septins, which are known to function in cell division and cytoskeletal structure.

M. Mostowy et al., “Entrapment of intracytosolic bacteria by septin cage-like structures,” Cell Host Microbe, 8:433-44, 2010.

4. Bacterial mRNAs make better vaccines
Why live bacterial vaccines, even those with attenuated strains, induce a much stronger immune response than killed whole cell bacterial vaccines has been a puzzle for some time. New research shows that host cells can detect bacterial mRNAs—produced only by live bacteria—and that by acting as pattern recognition molecules, mRNAs can activate both innate and immune responses. Moreover, heat-killed E. coli vaccines were able to induce a stronger antibody response after being spiked with mRNAs.

L.E. Sander et al., “Detection of prokaryotic mRNA signifies microbial viability and promotes immunity,” Nature, 474:385-9, 2011.

5. Ancient mitochondrial protein
A crucial step for the transition of mitochondria from bacterial endosymbionts into true cellular organelles was the development of a system for importing nuclear-encoded proteins. While most eukaryotes rely on the mitochondrial outer membrane protein Tom40, mitochondrial-carrying protozoans called trypanosomes lack this protein. Researchers discovered trypanosomes instead use a protein, which they named the archaic translocase of the outer mitochondrial membrane (ATOM), related to a bacterial protein family involved in transporting proteins across membrane—suggesting it may be a relic of an archaic protein transport system.

M. Pusnik et al., “Mitochondrial preprotein translocase of trypanosomatids has a bacterial origin,” Curr Biol, 21:1738-43, 2011.

6. Gut bacteria aid viral infections
Researchers found that the mouse mammary tumor virus (MMTV) was capable of hijacking the lipopolysaccharide (LPS) of gut bacteria in mice in order to trigger a toll-like receptor 4 (TLR4)-mediated immune response—ultimately resulting in an anti-inflammatory response that enabled viral infection. The finding suggests that interfering with commensal bacteria through the use of antibiotics may thwart viral infection.

M. Kane et al., “Successful transmission of a retrovirus depends on the commensal microbiota,” Science, 334:245-9, 2011.

7. A caspase mix-up
Because Caspase-1 knockout mice are remarkably resistant to toxic shock following exposure to bacterial lipopolysaccharide (LPS), researchers have concluded that the proteolytic enzyme, known to be involved in cytokine activation and apoptosis, is the primary effector in the induction of toxic shock. However, this new study reported that Caspase-1 mutants are also Caspase-11 mutants (due to the physical proximity of the genes), and that it is Caspase-11 that in fact regulates inflammation by promoting Caspase-1 activity.

N. Kayagaki et al., “Non-canonical inflammasome activation targets caspase-11,” Nature, 479:117-21, 2011.

The F1000 Top 7 is a snapshot of the highest ranked articles from a 14-day period on Faculty of 1000 Microbiology, as calculated on November 14, 2011. Faculty Members evaluate and rate the most important papers in their field. To see the latest rankings, search the database, and read daily evaluations, visit

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