title: beta-arrestin1 interacts with the catalytic domain of the tyrosine kinase c-SRC. Role of beta-arrestin1-dependent targeting of c-SRC in receptor endocytosis.
abstract: beta-Arrestins can act as adapter molecules, coupling G-protein-coupled receptors to proteins involved in mitogenic as well as endocytic pathways. We have previously identified c-SRC as a molecule that is rapidly recruited to the beta2-adrenergic receptor in a beta-arrestin1-dependent manner. Recruitment of c-SRC to the receptor appears to be involved in pathways leading to receptor internalization and mitogen-activated protein kinase activation. This recruitment of c-SRC to the receptor involves an interaction between the amino-terminal proline-rich region of beta-arrestin1 and the Src homology 3 (SH3) domain of c-SRC, but deletion of the proline-rich domain does not totally ablate the interaction. We have found that a major interaction also exists between beta-arrestin1 and the catalytic or kinase domain (SH1) of c-SRC. We therefore hypothesized that a catalytically inactive mutant of the isolated catalytic subunit, SH1(kinase dead) (SH1(KD)), would specifically block those cellular actions of c-SRC that are mediated by beta-arrestin1 recruitment to the G-protein-coupled receptor. In contrast, the majority of cellular phosphorylations catalyzed by c-SRC, which do not involve interaction with the SH1 domain, would be predicted to be unaffected. The SH1(KD) mutant did indeed block beta2-adrenergic receptor internalization and receptor-stimulated tyrosine phosphorylation of dynamin, actions previously shown to be c-SRC-dependent. In contrast, SAM-68 and whole cell tyrosine phosphorylation by c-SRC was unaffected, indicating that the SH1(KD) mutant did not inhibit c-SRC tyrosine kinase activity in general. These results not only clarify the nature of the beta-arrestin1/c-SRC interaction but also implicate beta-arrestin1 as an important mediator of receptor internalization by recruiting tyrosine kinase activity to the cell surface to phosphorylate key endocytic intermediates, such as dynamin.
authors.affiliation: Department of Medicine, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: W E
authors.initials: WE
authors.lastname: Miller
authors.forename: S
authors.initials: S
authors.lastname: Maudsley
authors.forename: S
authors.initials: S
authors.lastname: Ahn
authors.forename: K D
authors.initials: KD
authors.lastname: Khan
authors.forename: L M
authors.initials: LM
authors.lastname: Luttrell
authors.forename: R J
authors.initials: RJ
authors.lastname: Lefkowitz
mesh_terms: D019390:Arrestins / Q000502:physiology*; D000081247:CSK Tyrosine-Protein Kinase; D020134:Catalytic Domain; D002460:Cell Line; D034281:Dynamins; D004705:Endocytosis; D066246:ErbB Receptors / Q000502:physiology; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006801:Humans; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000502:physiology*; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014443:Tyrosine / Q000378:metabolism; D000071557:beta-Arrestins; D018909:src Homology Domains; D019061:src-Family Kinases
chemical_list: D019390:Arrestins; D018343:Receptors, Adrenergic, beta-2; D000071557:beta-Arrestins; D014443:Tyrosine; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D020558:GTP Phosphohydrolases; D034281:Dynamins