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Full-Text Articles in Life Sciences
Dissection Of Nodule Development By Supplementation Of Rhizobium Leguminosarum Biovar Phaseoli Purine Auxotrophs With 4-Aminoimidazole-5-Carboxamide Riboside, Jeffrey D. Newman, Bruce W. Schultz, K. Dale Noel
Dissection Of Nodule Development By Supplementation Of Rhizobium Leguminosarum Biovar Phaseoli Purine Auxotrophs With 4-Aminoimidazole-5-Carboxamide Riboside, Jeffrey D. Newman, Bruce W. Schultz, K. Dale Noel
Biological Sciences Faculty Research and Publications
Purine auxotrophs of Rhizobium leguminosarum biovar phaseoli CFN42 elicit uninfected pseudonodules on bean (Phaseolus vulgaris L.). Addition of 4-aminoimidazole-5-carboxamide (AICA) riboside to the root medium during incubation of the plant with these mutants leads to enhanced nodule development, although nitrogenase activity is not detected. Nodules elicited in this manner had infection threads and anatomical features characteristic of normal nodules, such as peripheral vasculature rather than the central vasculature of the pseudonodules that were elicited without AICA riboside supplementation. Although 105 to 106 bacteria could be recovered from these nodules after full development, bacteria were not observed in …
Heterogeneous Nuclear Ribonucleoprotein A1 Catalyzes Rna.Rna Annealing, Stephen Munroe, Xiaofan Dong
Heterogeneous Nuclear Ribonucleoprotein A1 Catalyzes Rna.Rna Annealing, Stephen Munroe, Xiaofan Dong
Biological Sciences Faculty Research and Publications
Within the nucleus, pre-mRNA molecules are complexed with a set of proteins to form heterogeneous nuclear ribonucleoprotein complexes. A1, an abundant RNA binding protein present in these complexes, has been shown to bind selectively to single-stranded RNAs and destabilize base-pairing interactions. In this study.A1 is shown to promote the rate of annealing of complementary RNA strands greater than 300-fold under a wide range of salt concentration and temperature. Maximal annealing is observed under saturating or near saturating concentrations of protein, but annealing decreases sharply at both higher and lower concentrations of A1. Kinetic analysis shows that the rate of annealing …
Modulation By Camp Of A Slowly Activating Potassium Channel Expressed In Xenopus Oocytes, Edward M. Blumenthal, Leonard K. Kaczmarek
Modulation By Camp Of A Slowly Activating Potassium Channel Expressed In Xenopus Oocytes, Edward M. Blumenthal, Leonard K. Kaczmarek
Biological Sciences Faculty Research and Publications
When expressed in the Xenopus oocyte, the minK protein induces a slowly activating voltage-dependent potassium current (Isk). We studied the modulation of this current by altering intracellular cAMP levels and found that the amplitude of Isk is dramatically increased by treatments that raise cAMP levels and decreased by agents that lower cAMP levels. Preinjection of a protein inhibitor of the cAMP-dependent protein kinase blocked the effects of increased cAMP levels. There were no changes in the voltage dependence or kinetics of Isk. Mutations that eliminate a potential phosphorylation site on the minK protein did …