14-05-2013 | Fatih Demir; Claudia Horntrich; Jörg O. Blachutzik; Sönke Scherzer; Yvonne Reinders; Sylwia Kierszniowska; Waltraud ..., Proceedings of the National Academy of Sciences current issue, 2013

The phytohormone abscisic acid (ABA) plays a key role in the plant response to drought stress. Hence, ABA-dependent gene transcription and ion transport is regulated by a variety of protein kinases and phosphatases. However, the nature of the membrane-delimited ABA signal transduction steps ...

more

07-05-2013 | Yunlong Du; Ricardo Tejos; Martina Beck; Ellie Himschoot; Hongjiang Li; Silke Robatzek; Steffen Vanneste; Jiří Friml, Proceedings of the National Academy of Sciences current issue, 2013

Removal of cargos from the cell surface via endocytosis is an efficient mechanism to regulate activities of plasma membrane (PM)-resident proteins, such as receptors or transporters. Salicylic acid (SA) is an important plant hormone that is traditionally associated with pathogen defense. ...

more

07-05-2013 | Alessandro Michelucci; Thekla Cordes; Jenny Ghelfi; Arnaud Pailot; Norbert Reiling; Oliver Goldmann; Tina Binz; Andr ..., Proceedings of the National Academy of Sciences current issue, 2013

Immunoresponsive gene 1 (Irg1) is highly expressed in mammalian macrophages during inflammation, but its biological function has not yet been elucidated. Here, we identify Irg1 as the gene coding for an enzyme producing itaconic acid (also known as methylenesuccinic acid) through the ...

more

16-04-2013 | Guodong Zhang; Dipak Panigrahy; Lisa M. Mahakian; Jun Yang; Jun-Yan Liu; Kin Sing Stephen Lee; Hiromi I. Wettersten; ..., Proceedings of the National Academy of Sciences current issue, 2013

Epidemiological and preclinical evidence supports that omega-3 dietary fatty acids (fish oil) reduce the risks of macular degeneration and cancers, but the mechanisms by which these omega-3 lipids inhibit angiogenesis and tumorigenesis are poorly understood. Here we show that ...

more

09-04-2013 | Ming-Feng Tsai; Christopher Miller, Proceedings of the National Academy of Sciences current issue, 2013

To successfully colonize the human gut, enteric bacteria must activate acid resistance systems to survive the extreme acidity (pH 1.5–3.5) of the stomach. The antiporter AdiC is the master orchestrator of the arginine-dependent system. Upon acid shock, it imports extracellular arginine (Arg) ...

more

09-04-2013 | Suping Zhang; Christina C. N. Wu; Jessie-F. Fecteau; Bing Cui; Liguang Chen; Ling Zhang; Rongrong Wu; Laura Rassenti ..., Proceedings of the National Academy of Sciences current issue, 2013

Chronic lymphocytic leukemia (CLL) cells express high levels of CD44, a cell-surface glycoprotein receptor for hyaluronic acid. We found that a humanized mAb specific for CD44 (RG7356) was directly cytotoxic for leukemia B cells, but had little effect on normal B cells. Moreover, RG7356 could ...

more

09-04-2013 | Ming-Feng Tsai; Patrick McCarthy; Christopher Miller, Proceedings of the National Academy of Sciences current issue, 2013

The bacterial antiporter GadC plays a central role in the glutamate (Glu)-dependent acid resistance system, which protects enteric bacteria against the extreme acidity of the human stomach. Upon acid shock, GadC imports Glu into the cytoplasm, where Glu decarboxylases consume a cytoplasmic ...

more

02-04-2013 | Karan S. Hingorani; Lila M. Gierasch, Proceedings of the National Academy of Sciences current issue, 2013

The evolutionary pressure to populate rewarding niches can require organisms to survive high-risk environments. For bacteria that inhabit the nutrient-rich human gut, whether they are our friends or foes, the trip through the stomach requires clever strategies to survive harsh, low-pH ...

more

02-04-2013 | Yuquan Xu; Tong Zhou; Zhengfu Zhou; Shiyou Su; Sue A. Roberts; William R. Montfort; Jia Zeng; Ming Chen; Wei Zhang; ..., Proceedings of the National Academy of Sciences current issue, 2013

Resorcylic acid lactones and dihydroxyphenylacetic acid lactones represent important pharmacophores with heat shock response and immune system modulatory activities. The biosynthesis of these fungal polyketides involves a pair of collaborating iterative polyketide synthases (iPKSs): a highly ...

more

26-03-2013 | Guillaume H. V. Bertrand; Vladimir K. Michaelis; Ta-Chung Ong; Robert G. Griffin; Mircea Dincă, Proceedings of the National Academy of Sciences current issue, 2013

We report the synthesis and characterization of covalent organic frameworks (COFs) incorporating thiophene-based building blocks. We show that these are amenable to reticular synthesis, and that bent ditopic monomers, such as 2,5-thiophenediboronic acid, are defect-prone building blocks that ...

more