Four Key Steps Control Glycolytic Flux in Mammalian Cells.

Altered glycolysis is a hallmark of diseases including diabetes and cancer. Despite intensive study of the contributions of individual glycolytic enzymes, systems-level analyses of flux control through glycolysis remain limited. Here, we overexpress in two mammalian cell lines the individual enzymes catalyzing each of the 12 steps linking extracellular glucose to excreted lactate, and find substantial flux control at four steps: glucose import, hexokinase, phosphofructokinase, and lactate export (and not at any steps of lower glycolysis).

Lipidomics identifies a requirement for peroxisomal function during influenza virus replication.

Influenza virus acquires a host-derived lipid envelope during budding, yet a convergent view on the role of host lipid metabolism during infection is lacking. Using a mass spectrometry-based lipidomics approach, we provide a systems-scale perspective on membrane lipid dynamics of infected human lung epithelial cells and purified influenza virions. We reveal enrichment of the minor peroxisome-derived ether-linked phosphatidylcholines relative to bulk ester-linked phosphatidylcholines in virions as a unique pathogenicity-dependent signature for influenza not found in other enveloped viruses.

Sialic acid linkage in glycosphingolipids is a molecular correlate for trafficking and delivery of extracellular cargo.

Gangliosides, glycosphingolipids containing sialic acid moieties, are well known mediators of transmembrane signaling and endocytosis at the plasma membrane. However, little is known about their precise regulatory role at the cell periphery for intracellular sorting of extracellular cargo. Here we inspected published scientific literature for two types of cargoes, namely bacterial toxins and viruses, regarding their usage of gangliosides.

The greasy response to virus infections.

Virus replication requires lipid metabolism, but how lipids mediate virus infection remains obscure. In this issue, Amini-Bavil-Olyaee et al. (2013) reveal that IFITM proteins disturb cholesterol homeostasis to block virus entry.

The stem region of premembrane protein plays an important role in the virus surface protein rearrangement during dengue maturation.

Background: Dengue virus surface proteins, envelope (E) and pre-membrane (prM), undergo rearrangement during the maturation process at acidic condition.

Results: prM-stem region binds tighter to both E protein and lipid membrane when environment becomes acidic.

Conclusion: At acidic condition, E proteins are attracted to the membrane-associated prM-stem.