Actins are highly conserved proteins that are involved in various types of cell motility. Polymerization of globular actin (G-actin) leads to a structural filament (F-actin) in the form of a two-stranded helix. Each actin can bind to 4 others. In tailbud embryos, expressed in embryonic muscle (myotomes). In adults, expressed in adult limb muscle. Expressed in developing embryos and adults. Oxidation of Met-46 and Met-49 by MICALs (MICAL1, MICAL2 or MICAL3) to form methionine sulfoxide promotes actin filament depolymerization. MICAL1 and MICAL2 produce the (R)-S-oxide form. The (R)-S-oxide form is reverted by MSRB1 and MSRB2, which promotes actin repolymerization. Monomethylation at Lys-86 (K86me1) regulates actin-myosin interaction and actomyosin-dependent processes. Demethylation by ALKBH4 is required for maintaining actomyosin dynamics supporting normal cleavage furrow ingression during cytokinesis and cell migration. Methylated at His-75 by SETD3. Xenopus contains at least three sarcomeric alpha actin genes that are preferentially expressed in either heart or skeletal muscle. The cardiac versus skeletal expression patterns of actins are probably sequence-dependent; Xenopus cardiac actins contain a Glu at position 3 of the mature peptide, whereas skeletal actins contain an Asp at this position. Belongs to the actin family.