Tubulin beta-4A chain

Tubulin beta-4A chain is a is_associated_with::protein that in humans is encoded by the TUBB4A is_associated_with::gene. Two is_associated_with::tubulin beta-4 chain is_associated_with::proteins are encoded in the human genome by the is_associated_with::genes TUBB4A (this entry) and TUBB4B. Tubulin is the major constituent of is_associated_with::microtubules, a key components of the is_associated_with::cytoskeleton. It binds two moles of GTP, one at an exchangeable site on the beta-chain and one at a non-exchangeable site on the alpha-chain. TUBB4A is preferentially and highly expressed in the central nervous system.

Clinical signficance
Mutations in TUBB4A have been associated with two neurological disorders.

An R2G substitution in the autoregulatory MREI domain of TUBB4A has been identified as the cause of 'hereditary whispering dysphonia' or DYT4.

A de novo D249N is_associated_with::mutation has been identified as the cause of a rare is_associated_with::leukoencephalopathy, hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC).

Mutations in TUBB4A are associated to Pelizaeus-Merzbacher disease.