Dynein Is Involved in the Movement, Distribution, Acidity, and Transfer of Melanosomes

The study reveals that Dynlt3, a component of the cytoplasmic dynein complex, plays a crucial role in the transport, acidity regulation, and efficient transfer of melanosomes to keratinocytes, which are key processes in skin pigmentation. When Dynlt3 levels are decreased in Mus musculus melanocytes, pigmented melanosomes move more directionally, resulting in their peripheral localization in the cell. These melanosomes are more acidic than normal but remain highly pigmented, leading to less efficient melanosome transfer. The study also found that the level of Dynlt3 is dependent on β-catenin activity, indicating a role of the Wnt/β-catenin signaling pathway in melanocyte and skin pigmentation, and in the transport, positioning, and acidity of melanosomes necessary for their transfer.