TY - JOUR T1 - Increased Expression of Golli Myelin Basic Proteins Enhances Calcium Influx into Oligodendroglial Cells JF - The Journal of Neuroscience JO - J. Neurosci. SP - 12690 LP - 12699 DO - 10.1523/JNEUROSCI.2381-07.2007 VL - 27 IS - 46 AU - Pablo M. Paez AU - Vilma Spreuer AU - Vance Handley AU - Ji-Ming Feng AU - Celia Campagnoni AU - Anthony T. Campagnoni Y1 - 2007/11/14 UR - http://www.jneurosci.org/content/27/46/12690.abstract N2 - The myelin basic protein (MBP) gene encodes two families of proteins: the classic MBP constituents of myelin and the golli-MBPs, the function of which is less well understood. Previous work suggests that golli proteins may play a role in Ca2+ homeostasis in oligodendrocytes (OLs) and in T-cells. Overexpression of golli in OL cell lines induces elaboration of sheets and processes. Live imaging of these cells revealed a rapid retraction of the processes and sheets after depolarization with high K+. This phenomenon was associated with a significant increase in [Ca2+]int without changes in cell viability. The results indicated that golli produced its effect through Ca2+ influx, rather than Ca2+ release from intracellular stores. Furthermore, a specific [Ca2+]int chelator (BAPTA) or Cd2+, a specific blocker of voltage-operated Ca2+ channels, abolished the ability of golli to promote process extension in a dose-dependent manner. Analysis of the golli protein identified a myristoylation site at the C terminus of the golli domain, which was essential for the action of golli on Ca2+ influx, suggesting that binding of golli to the plasma membrane is important for modulating Ca2+ homeostasis. High-resolution spatiotemporal analysis along N19 processes revealed higher-amplitude local Ca2+ influx in regions with elevated levels of golli. These findings suggest a key role for golli proteins in regulating voltage-gated Ca2+ channels in OLs during process remodeling. Our observations are consistent with the hypothesis that golli proteins, as a part of a protein complex, modulate Ca2+ influx at the plasma membrane and along OL processes. ER -