Open AccessEndocytosis of the Aspartic Acid/Glutamic Acid Transporter Dip5 Is Triggered by Substrate-Dependent Recruitment of the Rsp5 Ubiquitin Ligase via the Arrestin-Like Protein Aly2
Author(s) -
Riko Hatakeyama,
Masao Kamiya,
Taishi Takahara,
Tatsuya Maeda
Publication year - 2010
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.00464-10
Subject(s) - endocytosis , ubiquitin ligase , biology , microbiology and biotechnology , ubiquitin , biochemistry , endosome , receptor , gene
Endocytosis of nutrient transporters is stimulated under various conditions, such as elevated nutrient availability. InSaccharomyces cerevisiae , endocytosis is triggered by ubiquitination of transporters catalyzed by the E3 ubiquitin ligase Rsp5. However, how the ubiquitination is accelerated under certain conditions remains obscure. Here we demonstrate that closely related proteins Aly2/Art3 and Aly1/Art6, which are poorly characterized members of the arrestin-like protein family, mediate endocytosis of the aspartic acid/glutamic acid transporter Dip5. Inaly2Δ cells, Dip5 is stabilized at the plasma membrane and is not endocytosed efficiently. Efficient ubiquitination of Dip5 is dependent on Aly2.aly1Δ cells also show deficiency in Dip5 endocytosis, although less remarkably thanaly2Δ cells. Aly2 physically interactsin vivo with Rsp5 at its PY motif and also with Dip5, thus serving as an adaptor linking Rsp5 with Dip5 to achieve Dip5 ubiquitination. Importantly, the interaction between Aly2 and Dip5 is accelerated in response to elevated aspartic acid availability. This result indicates that the regulation of Dip5 endocytosis is accomplished by dynamic recruitment of Rsp5 via Aly2.