GLN1 GLN2 | GS1 GS2 glutamine synthetase global antibody

Brachypodium distachyon, Brassica napus, Camellia sinensis, Citrus clementina, Cucumis melo, Daphnia magna, Datisca glomerata, Emiliania huxleyi, Eucalyptus grandis, Gazania splendens, Genlisea aurea, Glycine max, Helianthus annuus, Hordeum vulgare, Oryza sativa, Panax quinquefolius, Phaseolus angularis, Phytophthora cinnamomi, Populus trichocarpa, Saccharum officinarum, Securigera parviflora, Solanum lycopersicum, Solanum tuberosum, Stevia rebaudiana, Theobroma cacao, Zea mays, Vitis labrusca

GLN1 dicots including: Brassica napus, Phaseolus vulgaris, monocots including: Hordeum vulgare, Oryza sativa, trees: Pinus sylvestris, Populus sp., Zosteria marina

GLN2 dicots including: Brassica napus, Glycine max, Phaseolus vulgaris, monocots including: Triticum aestivum, Oryza sativa

GLN3: Zea mays,

GLN1 in algae: Chlamydomonas reinhardii

The detection of GS1 and GS2 proteins was performed using the crude extract of soluble proteins from Oryza sativa plants: Ref: Reference (control); D: Drought; CO₂: High CO₂ D+CO₂: Drought + High CO₂. Fresh leaves samples were ground until obtaining a fine powder in presence of liquid N₂, ice-cold 100 mM K-phosphate buffer (pH 7.0) containing 1 mM EDTA and 2 mM ascorbic acid. After centrifugation at 14,000 x g for 30 min, the supernatant was collected and used as protein extract. All extraction stages were carried out at 4°C. The total soluble protein was measured according to the Bradford’s method. Leaf protein extracts were first separated by SDS-PAGE (Laemmli 1970). Equal amounts of protein (20 µg) were electrophoretically transferred to a nitrocellulose membrane (Towbin et al. 1979). Polypeptide detection was performed using specific polyclonal antibodies against GS1 and GS2 (AS08 295, Agrisera, Sweden). Membranes were blocked for 3 hours with 5% non-fat milk in saline Tris-HCl buffer (100 mM Tris-HCl, pH 7.6, 150 mM NaCl), incubated with GS antibody overnight and after with alkaline phosphatase-conjugated secondary antibody by 6 hours. The protein detection was developed using NBT/BCIP (Sigma-Aldrich©, USA) by adding 1 tablet to 10 mL dH₂O, until bands were visualized.

Courtesy of Dr. Ana Karla Lobo, Laboratory of Plant Metabolism, Federal University of Ceara, Brazil

Glutamine synthetase (GLN or GS) is one of the key enzymes involved in nitrogen metabolism of plants. It catalyses the synthesis of glutamine from glutamate and ammonia in an ATP-dependent reaction. There are two general classes of glutamine synthetase in plants: GLN1, a cytosolic form and GLN2, a chloroplastic form. GLN1 is highly abundant in the vascular elements of roots nodules, flowers and fruits, functioning in the assimilation of ammonium and the biosynthesis of glutamine for nitrogen transport. GLN2 is encoded by a single gene and is highly abundant in leaf mesophyll chloroplasts. Here GLN functions in the assimilation of ammonia produced from photorespiration and the reduction of nitrate in the chloroplasts