Actions of Rab27B ‐GTPase on mammalian central excitatory synaptic transmission

Members of the Rab3 gene family are considered central to membrane trafficking of synaptic vesicles at mammalian central excitatory synapses. While functional roles of Rab3A have been well ‐established, little functional information exists on the role of Rab27B in synaptic transmission. Our results provide a novel perspective in suggesting that Rab27B and Rab3A act synergistically, perhaps via sequential effector recruitment or signaling for presynaptic LTP expression in this hippoc ampal synaptic region. AbstractMembers of the Rab3 gene family are considered central to membrane trafficking of synaptic vesicles at mammalian central excitatory synapses. Recent evidence, however, indicates that the Rab27B ‐GTPase, which is highly homologous to the Rab3 family, is also enriched on SV membranes and co‐localize with Rab3A and Synaptotagmin at presynaptic terminals. While functional roles of Rab3A have been well‐established, little functional information exists on the role of Rab27B in synaptic tra nsmission. Here we report on functional effects of Rab27B at SC‐CA1 and DG‐MF hippocampal synapses. The data establish distinct functional actions of Rab27B and demonstrate functions of Rab27B that differ between SC‐CA1 and DG‐MF synapses. Rab27B knockout reduced frequency facilitation compa red to wild‐type (WT) controls at the DG/MF‐CA3 synaptic region, while increasing facilitation at the SC‐CA1 synaptic region. Remarkably, Rab27B KO resulted in a complete elimin...

Source: Physiological Reports - April 30, 2020 Category: Physiology Authors: Erwin R. Arias ‐Hervert, Nicole Xu, Meredith Njus, Geoff G. Murphy, Yanan Hou, John A. Williams, Stephen I. Lentz, Stephen A. Ernst, Edward L. Stuenkel Tags: ORIGINAL RESEARCH Source Type: research