Microtubule-associated protein 4

Microtubule-associated protein 4 (MAP4) is a non-neuronal microtubule-associated protein that promotes microtubule assembly (UniProt: P27816). The 121 kDa protein functions in stabilizing and organizing the cytoskeletal network through interactions with tubulin polymers.

MAP4 is expressed broadly across tissues and participates in microtubule dynamics, which are critical for cellular morphology and intracellular transport. No disease associations are explicitly documented in the UniProt record for this entry.

MAP4 shows elevated abundance in Alzheimer's disease brain tissue, with a mean log2 fold-change of +0.52 in post-mortem AD samples compared to age-matched controls (Chaparral AD proteomics). This upregulation was detected via TMT-labeled quantitative proteomics across four subcellular fractions, suggesting a potential compensatory response or pathological accumulation of cytoskeletal proteins in the AD brain. The functional role of MAP4 in microtubule stability may be relevant to AD-associated axonal and dendritic pathology.