Table 1.

Examples of function, targeting, and regulation of unconventional myosins, organized by myosin class

Name	Class	Species	Example illustrated
Myo1a	I	Vertebrates	Regulation of membrane tension in intestinal brush border cells
Myo1b	I	Rat	Differential expression patterns of splice isoforms that behave differently under load
Myo1c	I	Vertebrates	Adaptation in hair-cell stereocilia
Myo1c	I	Mouse	Ca²⁺-dependent regulation of cargo binding in adipocytes upon insulin stimulation
Myo1f	I	Mouse	Migration versus adhesion of neutrophils
Myo1g	I	Mammals	Pleckstrin homology domain-mediated binding to phosphoinositides that results in tight association with plasma membranes
Myosin I	I	Yeast	Stimulation of actin nucleation/polymerization
Myosin I	I	Yeast	Inactivation by tropomyosin-associated filaments
Myosin I	I	Acanthamoeba, Dictyostelium, yeast	Phosphorylation at TEDS rule site required for myosin function
Myo3A	III	Mammals	Autophosphorylation of motor domain affects motor function and localization
Myo2p	V	Yeast	Degradation of cargo-binding protein Vac17p provides possible mechanism for cargo switching
Myo4p	V	Yeast	Transport of mRNAs to bud tip
Myosin V	V	Yeast	Tropomyosin-dependent effect on motor’s ATPase rates and processivity
Myosin V	V	Mouse, Xenopus	Tethers melanosomes to cortical actin cytoskeleton
Myosin V	V	Vertebrates	Cell cycle– or signaling-dependent phosphorylation of tail domain regulates motor activity
Myosin V	V	Mammals	Interaction with the melanophilin adaptor-Rab27a complex is required for melanosome transport
Myosin V	V	Mammals, Drosophila	Concentration of Ca²⁺ affects processive movement, which might influence function in fly photoreceptors
Myosin Va	V	Mammals	Disruption of interaction with SNARE complex by Ca²⁺ regulates signaling
Myosin Va	V	Mammals	Differentially spliced exons provide different binding sites for cargo-binding proteins
Myosin VI	VI	Drosophila	Actin organization in spermatid individualization
Myosin VI	VI	Mammals, Drosophila	Potential cargo-mediated dimerization
Myosin VI	VI	Mammals	Different splice isoforms show different localization patterns and may play different roles in endocytosis
Myosin VIIa	VII	Mammals	Ca²⁺ disrupts inhibited state in which head and tail interact with each other
Myosin VII	VII	Mammals	Formation of a complex with MyRIP and Rab27a is required for targeting in retinal pigment epithelium
Myosin VIIa	VII	Mammals	FERM domain in tail recruits myosin to a large complex involved in cell adhesion
Myosin X	X	Mammals	Preferential movement on bundled actin, such as in filopodia
Myosin XI-K, −1, -2, -B, and -I	XI	Flowering plants	Family of myosins that play overlapping roles in vesicle trafficking and organelle motility
MyoA	XIV	Apicomplexan parasites	Cell movement (gliding motility) and infectivity
MyoA	XIV	Toxoplasma	Effect of lipid composition on localization of myosin complex in membrane
Myo18a	XVIII	Human	Organization and structure of Golgi complex
Myo19	XIX	Mammals	Transport of mitochondria in neurons