Tubulin beta-4A chain

Tubulin beta-4A chain (TUBB4A) is a core structural protein that forms microtubules, the major cytoskeletal component essential for cellular architecture and transport (UniProt: P04350). Beta-tubulin combines with alpha-tubulin to form heterodimers that polymerize into microtubule protofilaments, which grow through GTP-dependent addition at their ends and stabilize beneath a protective cap.

TUBB4A is associated with two primary neurological disorders documented in UniProt: dystonia 4 (torsion, autosomal dominant; DYT4), characterized by progressive laryngeal dysphonia and involuntary muscle contractions, and leukodystrophy hypomyelinating 6 (HLD6), a disorder presenting with delayed motor development, extrapyramidal movement disorders, spastic tetraplegia, and progressive cognitive decline.

Regarding Alzheimer's Disease, TUBB4A shows an ambiguous direction of change across subcellular fractions in human post-mortem AD brain compared to age-matched controls (Chaparral AD proteomics). The mean log2 fold-change is −0.0727, indicating minimal net alteration, though this masks potentially discordant changes across the examined fractions (P2, P3, S2, S3) in this TMT-labeled proteomics study.