Model of alpha-actinin CH1 bound to F-actin
[ACTB_HUMAN] Defects in ACTB are a cause of dystonia juvenile-onset (DYTJ) [MIM:607371]. DYTJ is a form of dystonia with juvenile onset. Dystonia is defined by the presence of sustained involuntary muscle contraction, often leading to abnormal postures. DYTJ patients manifest progressive, generalized, dopa-unresponsive dystonia, developmental malformations and sensory hearing loss. Defects in ACTB are the cause of Baraitser-Winter syndrome type 1 (BRWS1) [MIM:243310]. A rare developmental disorder characterized by the combination of congenital ptosis, high-arched eyebrows, hypertelorism, ocular colobomata, and a brain malformation consisting of anterior-predominant lissencephaly. Other typical features include postnatal short stature and microcephaly, intellectual disability, seizures, and hearing loss.
[ACTB_HUMAN] Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells. [ACTN3_HUMAN] F-actin cross-linking protein which is thought to anchor actin to a variety of intracellular structures. This is a bundling protein.
Publication Abstract from PubMed
Many actin-binding proteins contain calponin homology (CH) domains, but the manner in which these domains interact with F-actin has been controversial. Crystal structures have shown the tandem CH domains of alpha-actinin to be in a compact, closed conformation, but the interpretations of complexes of such tandem CH domains with F-actin have been ambiguous. We show that the tandem CH domains of alpha-actinin bind F-actin in an open conformation, explaining mutations that cause human diseases and suggesting that the opening of these domains may be one of the main regulatory mechanisms for proteins with tandem CH domains.
Opening of tandem calponin homology domains regulates their affinity for F-actin.,Galkin VE, Orlova A, Salmazo A, Djinovic-Carugo K, Egelman EH Nat Struct Mol Biol. 2010 May;17(5):614-6. Epub 2010 Apr 11. PMID:20383143
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.