Mutation E334Q in ACTG1 leads to perturbed interactions with cofilin and cytoskeletal myosin isoforms

Mutation E334Q in γ-cytoskeletal actin causes symptoms diverging from previously described actinopathies with a distinct clinical phenotype. The patients suffer from a mild speech disorder, frontal dysgyria, and severe hypotonia in some cases. Wild–type γ–actin and p.E334Q were produced as actin–thymosin β4–His–tag fusion proteins using the Baculovirus Sf9-insect cell system. Purification via NiNTA-affinity chromatography and digestion with chymotrypsin yielded homogeneous wild–type and mutant actin with N–terminal acetylation and without any additional sequence modifications, as verified by MS/MS analysis.