BRAIN SPECTRIN - OF MICE AND MEN

This article reviews our current knowledge of the structure of alpha s pectrins and beta spectrins in the brain, as well as their location an d expression within neural tissue. We discuss the known protein intera ctions of brain spectrin isoforms, and then describe results that sugg est an important role for spectrin (alpha SpII Sigma 1/beta SpII Sigma 1) in the Ca2+-regulated release of neurotransmitters. Evidence that supports a role for spectrin in the docking of synaptic vesicles to th e presynaptic plasma membrane and as a Ca2+ sensor protein that unclam ps the fusion machinery is described, along with the Casting the Line model, which summarizes the information. We finish with a discussion o f the value of spectrin and ankyrin-deficient mouse models in decipher ing spectrin function in neural tissue.