Myosins are actin-based motor molecules with ATPase activity (PubMed:16585515). Unconventional myosins serve in intracellular movements: can function in cells as a single-molecule cargo transporter (PubMed:16585515). A very slow and high-duty-ratio motor, may be suitable for tension maintenance of actin filaments (PubMed:16585515). Their highly divergent tails are presumed to bind to membranous compartments, which would be moved relative to actin filaments (PubMed:15579689). Plays a key role in the formation of cellular projections and other actin-based functions required for embryonic and larval viability (PubMed:15579689, PubMed:16585515). Necessary for auditory transduction: plays a role in Johnston's organ organization by functioning in scolopidial apical attachment and therefore to acoustic stimulus propagation from the antenna a2/a3 joint to transducing elements (PubMed:15886106, PubMed:27331610). Interaction with the myosin zip may be important for its function in scolopidial apical attachment (PubMed:27331610). During oogenesis it has Cad99c-dependent and Cad99c-independent roles in regulating the shape and spacing of the follicle cell microvilli which secrete eggshell material such as the vitelline membrane (PubMed:25236597). May be required for the normal expression of Cad99c in the follicle cell microvilli (PubMed:25236597). Homodimerizes in a two headed molecule through the formation of a coiled-coil rod (PubMed:16585515). Homodimers motility is approximately 8-10 times slower than that of myosin V, and its step size is 30 nm, which is consistent with the presence of five IQ motifs in its neck region (PubMed:16585515). Interacts with Cad99C (via the cytoplasmic domain) (PubMed:25236597, PubMed:27331610). Interacts with zip and Sans (PubMed:27331610). In scolopale cells (radially organized units in the Johnston's organ), protein is concentrated along actin-rich scolopale rods and more apically near scolopale cell-cap cell junctions (PubMed:15886106). In neurons, protein is concentrated near the basal body where neurons are tethered to the scolopale cell (PubMed:15886106). In germline and associated somatic cells of the ovary, it has a punctate distribution and associates with specific F-actin cell structures (PubMed:25236597). In germline cells, expressed in the F-actin-rich cytocortex of the oocyte (from stage 3, peaking at stages 9 to 10a) and in the cortex of nurse cells (from stage 6) (PubMed:25236597). Expressed in the microvilli and terminal web of follicle cells (PubMed:25236597). High expression at the base of the follicle cell microvilli in the brush border (PubMed:25236597). Expressed in the setae, micro- and macrochaetae on the head, thorax and wing. Throughout oogenesis expressed in the germline and associated somatic cells (at protein level) (PubMed:25236597). In germline cells of the germarium, expression levels peak during follicle formation and again from mid-oogenesis until late oogenesis (at protein level). Expressed both maternally and zygotically (PubMed:15579689). Expression peaks in 12-18 hour embryos, and continues at a constant low level of expression through to adults (PubMed:15579689). Flies exhibit altered morphology of setae, micro- and macrochaetae on the head, thorax and wing (PubMed:15579689). The number and distribution of setae on the thorax is altered, as is the morphology of the aristae (PubMed:15579689). Mutants also exhibit scolopidial apical detachment and overall Johnston's organ (JO) disorganization (PubMed:15579689). RNAi-mediated knockdown in Johnston's organs, disrupts the filamentous structure of the glycoprotein NompA at the apical junction (PubMed:27331610). NompA occurs as puncta and scolopidia detatch from the hinge of the second and third antennal segment (PubMed:27331610). Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Myosin family.