Cdc42 effector protein 4

CDC42 effector protein 4 (CDC42EP4) is a 356-amino acid cytoskeletal regulator that acts downstream of the small GTPase CDC42 to promote actin filament assembly and cell morphology changes (UniProt: Q9H3Q1). The protein is thought to mediate actin cytoskeleton organization, including pseudopodia formation when overexpressed in fibroblasts. Its molecular interactions position it within signaling pathways controlling cell shape dynamics and membrane protrusions.

CDC42EP4 shows Alzheimer's Disease relevance based on quantitative proteomics analysis. In human post-mortem AD brain tissue compared to age-matched controls, CDC42EP4 is significantly upregulated (mean log2 fold-change: 0.99) across multiple subcellular fractions in a TMT-labeled, data-dependent acquisition proteomics experiment (Chaparral AD proteomics). This finding spans three of four measured subcellular compartments (P2, P3, S2, S3), suggesting consistent elevation of this actin-organizing protein in the AD brain proteome and potentially linking cytoskeletal dysregulation to AD pathology.