The yeast multidrug transporter Pdr5 of the plasma membrane is ubiquitinated prior to endocytosis and degradation in the vacuole

FEBS Letters

Egner, Ralf¹  Kuchler, Karl¹ 

[1] Department of Molecular Genetics, University and Biocenter Vienna, Dr. Bohr-Gasse 9/2, A-1030 Vienna, Austria

关键词: Yeast;    ABC transporter;    Proteolysis;    Ubiquitin;    Endocytosis;    Vacuole;   

DOI  :  10.1016/0014-5793(95)01450-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have recently demonstrated that the Pdr5 ATP binding cassette multidrug transporter is a short-lived protein, whose biogenesis involves cell surface targeting followed by endocytosis and delivery to the vacuole for proteolytic turnover [Egner, R., Mahé, Y., Pandjaitan, R., and Kuchler, K. (1995) Mol. Cell. Biol. 15, 5879–5887]. Using c-myc epitope-tagged ubiquitin, we now have shown that Pdr5 is a ubiquitinated plasma membrane protein in vivo. Ubiquitination of Pdr5 was detected in both wild type and conditional end4 mutants defective in endocytic vesicle formation. Likewise, the Ste6 a-factor pheromone transporter, which represents another short-lived ABC transporter whose turnover requires vacuolar proteolysis, was also found to be ubiquitinated, and ubiquitin-modified Ste6 massively accumulated in end4 mutants at the restrictive temperature. By contrast, the plasma membrane ATPase Pma1, a long-lived and metabolically very stable protein, was found not to be ubiquitinated. Our results imply a novel function for ubiquitin in protein trafficking and suggest that ubiquitination of certain short-lived plasma membrane proteins may trigger their endocytic delivery to the vacuole for proteolytic turnover.

【 授权许可】

Unknown