α-
Arrestins, also called
arrestin-related trafficking adaptors (ARTs), constitute a large family of
proteins conserved from yeast to humans. Despite their evolutionary precedence over their extensively studied relatives of the β-
arrestin family, α-
arrestins have been discovered relatively recently, and thus their properties are mostly unexplored. The predominant function of α-
arrestins is the selective identification of
membrane proteins for ubiquitination and degradation, which is an important
element in maintaining
membrane protein homeostasis as well as global cellular metabolisms. Among members of the
arrestin clan, only α-
arrestins possess PY motifs that allow canonical binding to WW domains of Rsp5/NEDD4
ubiquitin ligases and the subsequent ubiquitination of
membrane proteins leading to their vacuolar/lysosomal degradation. The molecular mechanisms of the selective substrate's targeting, function, and regulation of α-
arrestins in response to different stimuli remain incompletely understood. Several functions of α-
arrestins in animal models have been recently characterized, including redox homeostasis regulation, innate immune response regulation, and
tumor suppression. However, the molecular mechanisms of α-
arrestin regulation and substrate interactions are mainly based on observations from the yeast Saccharomyces cerevisiae model. Nonetheless, α-
arrestins have been implicated in health disorders such as diabetes,
cardiovascular diseases,
neurodegenerative disorders, and
tumor progression, placing them in the group of potential therapeutic targets.