Erythrocyte adducin: A structural regulator of the red blood cell membrane

Adducin is an alpha, beta heterotetramer that performs multiple important functions in the human erythrocyte membrane First adducin forms a bridge that connects the spectrin-actin junctional complex to band 3, the major membrane-spanning potent in the bilayer Rupture of this bridge leads to membrane instability and spontaneous fragmentation Second. adducin caps the fast growing (bat bed) end of actin filaments. preventing the tetradecameric protofilaments from elongating into macroscopic F-actin microfilaments Third. adducin stabilizes the association between actin and spectrin, assuring that the junctional complex remains intact during the mechanical distortions experienced by the circulating cell And finally. adducin responds to stimuli that may be important in regulating the global properties of the cell, possibly including: cation transport. cell morphology and membrane deformability The text below summarizes the structural properties of adducin. its multiple functions in erythrocytes. and the consequences of engineered deletions of each of adducin subunits in transgenic mice (C) 2010 Elsevier Masson SAS All rights reserved