Ubiquitination differentially regulates clathrin-dependent internalization of protease-activated receptor-1. J Cell Biol 2007 Jun 04;177(5):905-16
Date
05/31/2007Pubmed ID
17535965Pubmed Central ID
PMC2064289DOI
10.1083/jcb.200610154Scopus ID
2-s2.0-34249905192 83 CitationsAbstract
Protease-activated receptor-1 (PAR1), a G protein-coupled receptor (GPCR) for thrombin, is irreversibly activated by proteolysis. Consequently, PAR1 trafficking is critical for the fidelity of thrombin signaling. PAR1 displays constitutive and agonist-induced internalization, which are clathrin and dynamin dependent but are independent of arrestins. The clathrin adaptor AP2 (adaptor protein complex-2) is critical for constitutive but not for activated PAR1 internalization. In this study, we show that ubiquitination negatively regulates PAR1 constitutive internalization and specifies a distinct clathrin adaptor requirement for activated receptor internalization. PAR1 is basally ubiquitinated and deubiquitinated after activation. A PAR1 lysineless mutant signaled normally but was not ubiquitinated. Constitutive internalization of ubiquitin (Ub)-deficient PAR1 was markedly increased and inhibited by the fusion of Ub to the cytoplasmic tail. Ub-deficient PAR1 constitutive internalization was AP2 dependent like the wild-type receptor. However, unlike wild-type PAR1, AP2 was required for the internalization of activated Ub-deficient receptor, suggesting that the internalization of ubiquitinated PAR1 requires different endocytic machinery. These studies reveal a novel function for ubiquitination in the regulation of GPCR internalization.
Author List
Wolfe BL, Marchese A, Trejo JAuthor
Adriano Marchese PhD Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adaptor Protein Complex 2Amino Acid Sequence
Animals
Cell Line
Clathrin
Dynamins
Humans
Molecular Sequence Data
Mutation
Protein Transport
Rats
Receptor, PAR-1
Ubiquitin
