Myosin-18A (MYO18A)

Myosin-18A (MYO18A) is an unconventional class 18 myosin found in mammals, encoded by the MYO18A gene on human chromosome 17. It acts as a cytoskeletal motor-like protein but, unlike conventional myosins, lacks appreciable ATPase-driven motor activity due to substitutions in key catalytic residues[1][2]. MYO18A exists in several splice isoforms, including MYO18Aα (which contains a PDZ domain), MYO18Aβ, and the muscle-specific MYO18Aγ. The protein participates in essential processes such as cell motility, actin cytoskeleton remodeling, formation of focal adhesions, stress fiber and sarcomere assembly, and Golgi apparatus organization[1][2][4]. MYO18A can act as a receptor for surfactant protein A (SP-R210) in immune cells, facilitating pathogen recognition and phagocytosis[2]. Disruption of MYO18A impairs cardiac sarcomeric architecture and leads to embryonic lethality with severe heart defects, highlighting its critical developmental role[1][2]. MYO18A is also implicated in cancer biology and possibly in other immune-mediated diseases. Despite these essential functions, MYO18A is not currently a direct therapeutic target and no drugs specifically modulate its activity[1][2].

Other names

Putative TGFB1-induced anti-apoptotic factor 1TIAF1Unconventional myosin-XVIIIaCD245KIAA0216MYSPDZMAJNSP-R210Molecule associated with JAK3 N-terminusMolecule associated with Jak-3 N-terminalSurfactant protein receptor SP-R21012 kDa TGF-beta-1-induced antiapoptotic factorMyosin containing a PDZ domainSP-A receptor subunit SP-R210 alphaSTGFB1-induced anti-apoptotic factor 1MysPDZSPR210

Not directly targeted by drugs; hypothesized mechanisms would involve modulation of actin cytoskeleton, immune recognition/response, or sarcomere assembly through interaction with MYO18A or its complexes.