Pib2-Dependent Feedback Control of the TORC1 Signaling Network by the Npr1 Kinase.

To adjust cell growth and metabolism according to environmental conditions, the conserved TORC1 signaling network controls autophagy, protein synthesis, and turnover. Here, we dissected the signals controlling phosphorylation and activity of the TORC1-effector kinase Npr1, involved in tuning the plasma membrane permeability to nitrogen sources. By evaluating a role of pH as a signal, we show that, although a transient cytosolic acidification accompanies nitrogen source entry and is correlated to a rapid TORC1-dependent phosphorylation of Npr1, a pH drop is not a prerequisite for TORC1 activation.

Waarnemingen.be - Plant occurrences in Flanders and the Brussels Capital Region, Belgium.

Waarnemingen.be - Plant occurrences in Flanders and the Brussels Capital Region, Belgium is a species occurrence dataset published by Natuurpunt. The dataset contains almost 1.

Identification of a Novel Regulatory Mechanism of Nutrient Transport Controlled by TORC1-Npr1-Amu1/Par32.

Fine-tuning the plasma-membrane permeability to essential nutrients is fundamental to cell growth optimization. Nutritional signals including nitrogen availability are integrated by the TORC1 complex which notably regulates arrestin-mediated endocytosis of amino-acid transporters. Ammonium is a ubiquitous compound playing key physiological roles in many, if not all, organisms.

The TORC1 effector kinase Npr1 fine tunes the inherent activity of the Mep2 ammonium transport protein.

The TORC1 complex controls cell growth upon integrating nutritional signals including amino-acid availability. TORC1 notably adapts the plasma membrane protein content by regulating arrestin-mediated endocytosis of amino-acid transporters. Here we demonstrate that TORC1 further fine tunes the inherent activity of the ammonium transport protein, Mep2, a yeast homologue of mammalian Rhesus factors, independently of arrestin-mediated endocytosis.

SNPs altering ammonium transport activity of human Rhesus factors characterized by a yeast-based functional assay.

Proteins of the conserved Mep-Amt-Rh family, including mammalian Rhesus factors, mediate transmembrane ammonium transport. Ammonium is an important nitrogen source for the biosynthesis of amino acids but is also a metabolic waste product. Its disposal in urine plays a critical role in the regulation of the acid/base homeostasis, especially with an acid diet, a trait of Western countries.