Isoform 2 of Microtubule-associated protein RP/EB family member 3

MAPRE3 isoform 2 is a microtubule-associated protein belonging to the RP/EB family, with a molecular weight of approximately 30 kDa (UniProt: Q9UPY8-2). Members of this family function as microtubule plus-end tracking proteins, playing roles in cytoskeletal regulation and cellular dynamics. The protein is expressed in human tissues but has no curated disease associations noted in UniProt.

In the context of Alzheimer's disease, MAPRE3 isoform 2 shows consistent downregulation in post-mortem AD brain tissue compared to age-matched controls. Quantitative proteomics analysis using TMT labeling across four subcellular fractions (P2, P3, S2, S3) revealed a mean log2 fold-change of −0.771 (Chaparral AD proteomics), indicating reduced protein abundance in AD pathology. This downregulation was observed in a single fraction, suggesting possible alterations in microtubule dynamics or cytoskeletal organization as part of the AD disease process.