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Cell

Title:		Ubiquitination of a yeast plasma membrane receptor signals its ligand-stimulated endocytosis
Author(s):		Hicke L; Riezman H;
Address:		"Department of Biochemistry, Biozentrum, University of Basel, Switzerland"
Journal Title:		Cell
Year:		1996
Volume:		84
Issue:		2
Page Number:		277 - 287
DOI:		10.1016/s0092-8674(00)80982-4
ISSN/ISBN:		0092-8674 (Print) 0092-8674 (Linking)
Abstract:		"Binding of alpha factor to Ste2p, a G protein-coupled plasma membrane receptor, activates a signal transduction pathway and stimulates endocytosis of the receptor-ligand complex. Ligand binding also induces ubiquitination of the Ste2p cytoplasmic tail. Protein ubiquitination is required for stimulated endocytosis of Ste2p, as internalization is 5- to 15-fold slower in ubc mutants that lack multiple ubiquitin-conjugating enzymes. In a C-terminal truncated form of Ste2p that is rapidly ubiquitinated and endocytosed in response to ligand binding, a single lysine to arginine substitution in its cytoplasmic tail eliminates both ubiquitination and internalization. Thus, ubiquitination of Ste2p itself is required for ligand-stimulated endocytosis. We propose that ubiquitination mediates degradation of receptor-ligand complexes, not via the proteasome, but by acting as a signal for endocytosis leading to subsequent degradation in the lysosome/vacuole"
Keywords:		Amino Acid Sequence Biological Transport Carboxypeptidases/metabolism Cathepsin A Cysteine Endopeptidases/metabolism Endocytosis/*physiology Hydrolases/physiology Ligands Ligases/genetics/physiology Lysine/metabolism Mating Factor Molecular Sequence Data;
Notes:		"MedlineHicke, L Riezman, H eng Research Support, Non-U.S. Gov't 1996/01/26 Cell. 1996 Jan 26; 84(2):277-87. doi: 10.1016/s0092-8674(00)80982-4"