Tubulin alpha-8 chain

Tubulin alpha-8 chain (TUBA8) is a major structural component of microtubules, which are cylindrical polymers essential for cellular architecture and dynamics (UniProt: Q9NY65). The protein functions as part of alpha-beta-tubulin heterodimers that polymerize into microtubule protofilaments; GTP hydrolysis by the alpha-tubulin subunit regulates microtubule stability and growth. Beyond its cytoskeletal role, TUBA8 is implicated in isolated macrothrombocytopenia-2, an autosomal dominant disorder affecting platelet morphology and number.

In Alzheimer's Disease, TUBA8 is consistently downregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics), with a mean log2 fold-change of −0.50 across one subcellular fraction. This reduction was detected using quantitative proteomics (TMT-labeled discovery mass spectrometry) across multiple subcellular compartments (P2, P3, S2, S3). The decreased expression of microtubule-associated proteins in AD brain may reflect impaired neuronal cytoskeletal integrity, a hallmark pathological feature of neurodegeneration.