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Ubiquitination differentially regulates clathrin-dependent internalization of protease-activated receptor-1. J Cell Biol 2007 Jun 04;177(5):905-16

Date

05/31/2007

Pubmed ID

17535965

Pubmed Central ID

PMC2064289

DOI

10.1083/jcb.200610154

Scopus ID

2-s2.0-34249905192   83 Citations

Abstract

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 J

Author

Adriano Marchese PhD Professor in the Biochemistry department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Adaptor Protein Complex 2
Amino Acid Sequence
Animals
Cell Line
Clathrin
Dynamins
Humans
Molecular Sequence Data
Mutation
Protein Transport
Rats
Receptor, PAR-1
Ubiquitin