BAR/IMD domain-containing adapter protein 2

BAIAP2 (BAR/IMD domain-containing adapter protein 2) is a cytoplasmic adapter protein that links membrane-bound small G-proteins to effector proteins, playing a central role in actin cytoskeleton reorganization. It mediates CDC42- and RAC1-dependent cytoskeletal dynamics, facilitates filopodia formation in concert with ENAH and EPS8, and supports neurite growth and actin bundling (UniProt: Q9UQB8).

The protein functions broadly in cytoskeletal regulation across diverse cellular contexts, including neuronal morphogenesis and response to bacterial infection. No non-AD disease associations are currently annotated in UniProt for this entry.

BAIAP2 is downregulated in Alzheimer's disease brain tissue relative to age-matched controls (Chaparral AD proteomics), with a mean log2 fold-change of −0.98 across post-mortem samples analyzed by TMT-labeled quantitative proteomics. This reduction in cytoskeletal regulator abundance may reflect disrupted neuronal architecture or actin dynamics characteristic of AD pathology.