Drebrin is a member of the newly identified ADF-H family of actin-binding proteins that share the structurally conserved actin-depolymerizing factor (ADF) binding module. It is composed of a single ADF-H domain at its N-terminus, followed by a non-conserved central region and a C-terminal SH3 domain. Three isoforms, E1 and E2 (embryonic) and A (adult), have been identified in the brain. An additional truncated form of drebrin A, s-drebrin/A2, is specifically expressed in the adult brain, but not in non-neuronal tissues. Drebrin is also widely expressed in a variety of cells including epithelial, endothelial, and smooth muscle cells and is associated at cell-cell adhering junction sites.
Drebrin (developmentally-regulated brain protein) is a major neuronal F-actin binding protein involved in the control of actin dynamics and neuronal morphogenesis. It colocalizes with actin filaments and dendritic-like cell processes and may be involved in actin remodeling. It binds to and dissociates F-actin stabilizing proteins such as α-actinin, fascin, and tropomyosin from actin filaments. It plays an important role in the formation of axons and dendrites during neuronal development and in neuronal plasticity in the adult brain.
