Myosin-5 (Myo5)

Myosin-5 is a double-headed molecular motor protein that plays a critical role in intracellular transport by moving organelles, vesicles, and other cargoes along actin filaments. It is composed of two identical heavy chains and multiple light chains, with each heavy chain containing an N-terminal motor domain responsible for actin binding and ATP hydrolysis, a lever arm with six IQ motifs for light chain binding, and a tail domain for cargo interaction. Myosin-5 is distinguished by its processivity and ability to take extended steps of approximately 36 nm, which is facilitated by its long lever arm. The protein is regulated by a tail-inhibition mechanism, where the globular tail domain (GTD) interacts with the motor domain to inhibit activity in the absence of cargo or calcium. Activation occurs when adaptor proteins or calcium disrupt this interaction, allowing Myosin-5 to adopt an extended conformation and perform its transport functions. Myosin-5 is involved in a variety of cellular processes, including organelle distribution, cell division, and synaptic vesicle transport, and has been implicated in several diseases, including neurodegenerative disorders and cancer.

Other names

Myosin VMyo5aMyo5bMyo5cMyosin-VMyosin class VMyosin heavy chain 5