Identification of a Novel Regulatory Mechanism of Nutrient Transport Controlled by @entity7093 - XXXX -Amu1/Par32.

@entity1 @entity1568 @entity3264 @entity13380 @entity7093 @entity3104 @entity375 @entity3689
UNASSIGNED: Fine-tuning the plasma-membrane permeability to essential nutrients is fundamental to cell growth optimization. Nutritional signals including @entity1568 availability are integrated by the @entity7093 complex which notably regulates arrestin-mediated endocytosis of @entity3689 transporters. @entity3104 is a ubiquitous compound playing key physiological roles in many, if not all, organisms. In @entity375 , it is a preferred @entity1568 source transported by three Mep proteins which are orthologues of the @entity1 Rhesus factors. By combining genetic, kinetic, biochemical and cell microscopy analyses, the current study reveals a novel mechanism enabling @entity7093 to regulate the inherent activity of @entity3104 transport proteins, independently of arrestin-mediated endocytosis, identifying the still functional orphan Amu1/Par32 as a selective regulator intermediate. We show that, under poor @entity1568 supply, the @entity7093 effector kinase' @entity13380 ' promotes phosphorylation of Amu1/Par32 which appears mainly cytosolic while @entity3104 transport proteins are active. Upon preferred @entity1568 supplementation, like @entity3264 or @entity3104 addition, @entity7093 upregulation enables @entity13380 inhibition and Amu1/Par32 dephosphorylation. In these conditions, as in @entity13380 -lacking cells, hypophosphorylated Amu1/Par32 accumulates at the cell surface and mediates the inhibition of specific @entity3104 transport proteins. We show that the integrity of a conserved repeated motif of Amu1/Par32 is required for the interaction with these transport proteins. This study underscores the diversity of strategies enabling @entity7093 - @entity13380 to selectively monitor cell permeability to nutrients by discriminating between transporters to be degraded or transiently inactivated and kept stable at the plasma membrane. This study further identifies the function of Amu1/Par32 in acute control of @entity3104 transport in response to variations in @entity1568 availability.
