MYO7A

Myosin VIIA is is_associated_with::protein that in humans is encoded by the MYO7A is_associated_with::gene. Myosin VIIA is a member of the unconventional is_associated_with::myosin superfamily of proteins. Myosins are is_associated_with::actin binding molecular motors that use the enzymatic conversion of ATP - ADP + inorganic phosphate (Pi) to provide the energy for movement.

Myosins are mechanochemical proteins characterized by the presence of a motor domain, an actin-binding domain, a neck domain that interacts with other proteins, and a tail domain that serves as an anchor. Myosin VIIA is an unconventional myosin with a very short tail. Unconventional myosins have diverse functions in is_associated_with::eukaryotic cells and are primarily thought to be involved in the movement or linkage of intra-cellular membranes and is_associated_with::organelles to the actin cytoskeleton via interactions mediated by their highly divergent tail domains.

MYO7A is expressed in a number of mammalian tissues, including is_associated_with::testis, is_associated_with::kidney, is_associated_with::lung, inner ear, is_associated_with::retina and the ciliated is_associated_with::epithelium of the nasal is_associated_with::mucosa.

Clinical significance
Mutations in the MYO7A gene cause the is_associated_with::Usher syndrome type 1B, a combined deafness/blindness disorder.

Model organisms
is_associated_with::Model organisms have been used in the study of MYO7A function. A spontaneous mutant mouse line, called Myo7ash1-6J was generated. Male and female animals underwent a standardized is_associated_with::phenotypic screen to determine the effects of deletion. Twenty three tests were carried out on is_associated_with::mutant mice and ten significant abnormalities were observed. Male is_associated_with::homozygous is_associated_with::mutant mice displayed a decreased body weight, a decrease in body fat, improved is_associated_with::glucose tolerance and abnormal is_associated_with::pelvic girdle bone morphology. Homozygous mutant mice of both sex displayed various abnormalities in a modified is_associated_with::SHIRPA test, including abnormal gait, tail dragging and an absence of pinna is_associated_with::reflex, a decrease in is_associated_with::grip strength, an increased thermal is_associated_with::pain threshold, severe is_associated_with::hearing impairment and a number of abnormal is_associated_with::indirect calorimetry and is_associated_with::clinical chemistry parameters.