Cytoskeleton

Abstract

The cytoskeleton consists primarily of microfilaments, microtubules, and intermediate filaments. Actin microfilaments have major role in growth, maintenance, and dynamic changes of growth cones and dendrites; stabilization of proteins at specific membrane locations; and vesicle dynamics during endocytosis and exocytosis. Microtubules provide the major tracks for intracellular transport and local cues for positioning of mitochondria and other organelles. The intermediate filaments in neurons are the neurofilaments that have a major role in regulating axonal caliber and mechanical stability. Glial fibrillary acid protein is a primary component of intermediate filaments in astrocytes. Nuclear lamins participate in regulation of the chromatin organization, trafficking of transcription factors across the nuclear envelope, and transduction of mechanical signals. Mutations affecting these cytoskeletal proteins produce a wide range of neurologic disorders, including neurodevelopmental disorders, peripheral neuropathies, myopathies, and leukodystrophy. All components of the cytoskeleton are involved in adult-onset neurodegenerative disorders.