The pleiotropic roles of autophagy regulators in melanogenesis.

Melanin pigments protect the skin and eyes from toxic insults and are critical for the normal functioning of multiple organ systems including the skin, eyes, and brain. Biochemical and genetic studies in both human and mice have revealed the molecular machinery controlling the transcription of genes encoding enzymes that produce melanin and the trafficking of these enzymes to the melanosome, a lysosome-related organelle dedicated to melanin synthesis. Recent functional genomic studies have identified a role for genes previously known to regulate autophagy, a cellular process that facilitates nutrient recycling during starvation, in the biogenesis of melanosomes in vitro and in vivo. In this review, we describe the pleiotropic roles of autophagy regulators in multiple vesicle trafficking processes, define a specific role for autophagy regulators in melanosome biogenesis, and shed light on how autophagy and autophagy regulators may play different roles in both the biogenesis of melanosomes and melanosome destruction.