May link Golgi membranes to the cytoskeleton and participate in the tensile force required for vesicle budding from the Golgi. Thereby, may play a role in Golgi membrane trafficking and could indirectly give its flattened shape to the Golgi apparatus. Alternatively, in concert with LURAP1 and CDC42BPA/CDC42BPB, has been involved in modulating lamellar actomyosin retrograde flow that is crucial to cell protrusion and migration (By similarity). May be involved in the maintenance of the stromal cell architectures required for cell to cell contact (By similarity). Regulates trafficking, expression, and activation of innate immune receptors on macrophages. Plays a role to suppress inflammatory responsiveness of macrophages via a mechanism that modulates CD14 trafficking. Acts as a receptor of surfactant-associated protein A (SFTPA1/SP-A) and plays an important role in internalization and clearance of SFTPA1-opsonized S.aureus by alveolar macrophages. Strongly enhances natural killer cell cytotoxicity (By similarity). Homodimer. Forms a tripartite complex with CDC42BPA/CDC42BPB and LURAP1 with the latter acting as an adapter connecting CDC42BPA/CDC42BPB and MYO18A. Binds F-actin; regulated by ADP and GOLPH3. Interacts with GOLPH3; the interaction is direct and may link Golgi membranes to the actin cytoskeleton. Interacts with JAK3. Interacts with MSR1 and CD14. Recruited to the Golgi apparatus by GOLPH3 (By similarity). Localizes to the postsynaptic Golgi apparatus region, also named Golgi outpost, which shapes dendrite morphology by functioning as sites of acentrosomal microtubule nucleation (PubMed:31522887). The myosin motor domain binds ADP and ATP but has no intrinsic ATPase activity. Mediates ADP-dependent binding to actin. Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Myosin family.