InterPro domain: IPR038185

The microtubule-based kinesin motors and actin-based myosin motors generate movements required for intracellular trafficking, cell division, and muscle contraction. In general, these proteins consist of a motor domain that generates movement and a tail region that varies widely from class to class and is thought to mediate many of the regulatory or cargo binding functions specific to each class of motor [ 1 ]. The Myosin Tail Homology 4 (MyTH4) domain has been identified as a conserved domain in the tail domains of several different unconventional myosins [ 2 ] and a plant kinesin-like protein [ 3 ], but has more recently been found in several non-motor proteins [ 4 ]. Although the function is not yet fully understood, there is an evidence that the MyTH4 domain of Myosin-X (Myo10) binds to microtubules and thus could provide a link between an actin-based motor protein and the microtubule cytoskeleton [ 5 ].

The MyTH4 domain is found in one or two copies associatedwith other domains, such as myosin head, kinesin motor, FERM, PH, SH3 and IQ. The domain is predicted to be largely alpha-helical, interrupted by three orfour turns. The MyTH4 domain contains four highly conserved regions designatedMGD (consensus sequence L(K/R)(F/Y)MGDhP, LRDE (consensus LRDEhYCQhhKQHxxxN),RGW (consensus RGWxLh), and ELEA (RxxPPSxhELEA), where h indicates ahydrophobic residue and x is any residue [ 6 ].

1. Tails of unconventional myosins. Cell. Mol. Life Sci. 56, 243-57
2. Myosin-VIIb, a novel unconventional myosin, is a constituent of microvilli in transporting epithelia. Genomics 72, 285-96
3. [Study on the hygienic quality of raw milk received in processing plants] Rev. Latinoam. Microbiol. 18, 175-8
4. MAX-1, a novel PH/MyTH4/FERM domain cytoplasmic protein implicated in netrin-mediated axon repulsion. Neuron 34, 563-76
5. A microtubule-binding myosin required for nuclear anchoring and spindle assembly. Nature 431, 325-9