title: Thioredoxin binding protein (TBP)-2/Txnip and α-arrestin proteins in cancer and diabetes mellitus.
abstract: Thioredoxin binding protein -2/ thioredoxin interacting protein is an α-arrestin protein that has attracted much attention as a multifunctional regulator. Thioredoxin binding protein -2 expression is downregulated in tumor cells and the level of thioredoxin binding protein is correlated with clinical stage of cancer. Mice with mutations or knockout of the thioredoxin binding protein -2 gene are much more susceptible to carcinogenesis than wild-type mice, indicating a role for thioredoxin binding protein -2 in cancer suppression. Studies have also revealed roles for thioredoxin binding protein -2 in metabolic control. Enhancement of thioredoxin binding protein -2 expression causes impairment of insulin sensitivity and glucose-induced insulin secretion, and β-cell apoptosis. These changes are important characteristics of type 2 diabetes mellitus. Thioredoxin binding protein -2 regulates transcription of metabolic regulating genes. Thioredoxin binding protein -2-like inducible membrane protein/ arrestin domain containing 3 regulates endocytosis of receptors such as the β(2)-adrenergic receptor. The α-arrestin family possesses PPXY motifs and may function as an adaptor/scaffold for NEDD family ubiquitin ligases. Elucidation of the molecular mechanisms of α-arrestin proteins would provide a new pharmacological basis for developing approaches against cancer and type 2 diabetes mellitus.
authors.affiliation: Institute for Virus Research, Graduate School of Biostudies, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo, Kyoto 606-8507, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Masutani
authors.forename: Eiji
authors.initials: E
authors.lastname: Yoshihara
authors.forename: So
authors.initials: S
authors.lastname: Masaki
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chen
authors.forename: Junji
authors.initials: J
authors.lastname: Yodoi