eng URI http://hdl.handle.net/10795/3279 βιολογία κυτταρολογία We investigated the role of all arrestin-like proteins of Aspergillus nidulans in respect to growth, morphology, sensitivity to drugs and specifically for the endocytosis and turnover of the uric acid-xanthine transporter UapA. A single arrestin-like protein, ArtA, is essential for HulARsp5-dependent ubiquitination and endocytosis of UapA in response to ammonium or substrates. Mutational analysis showed that residues 545–563 of the UapA C-terminal region are required for efficient UapA endocytosis, whereas the N-terminal region (residues 2–123) and both PPxY motives are essential for ArtA function. We further show that ArtA undergoes HulA-dependent ubiquitination at residue Lys-343 and that this modification is critical for UapA ubiquitination and endocytosis. Lastly, we show that ArtA is essential for vacuolar turnover of transporters specific for purines (AzgA) or L-proline (PrnB), but not for an aspartate/glutamate transporter (AgtA). Our results are discussed within the frame of recently proposed mechanisms on how arrestin-like proteins are activated and recruited for ubiquitination of transporters in response to broad range signals, but also put the basis for understanding how arrestin-like proteins, such as ArtA, regulate the turnover of a specific transporter in the presence of its substrates. 15 pp. LOMv1.0 creator LOMv1.0 publisher LOMv1.0 Scientific Coordinator LOMv1.0 Project Executing Organisation 2013-04-12 Digital Library of the Operational Programme "Education and Lifelong Learning" abstract types Text UapA Arresting-like protein Aspergillus nidulans Endocytosis Uric-acid/xanthine trasporter Purines Proteins Μικροβιολογία Μοριακή βιολογία Ενδοκύτωση Πρωτεΐνες Πουρίνες Ουρικό οξύ 7731456 application/pdf http://repository.edulll.gr/edulll/bitstream/10795/3279/2/3279_1.65_%ce%94%ce%97%ce%9c_12_4_13.pdf URI http://hdl.handle.net/10795/3279 LOMv1.0creator 2016-05-19T11:13:36Z LOMv1.0validator 2016-05-19T11:13:36Z LOMv1.0 gre no no Copyright EYD-EPEDBM (Operational Programme "Education and Lifelong Learning")