The Barbee Lab

Our laboratory is interested in understanding the basic molecular functions of cytoplasmic ribonucleoprotein (RNP) particles in polarized cells. We currently are using the Drosophila melanogaster neuromuscular junction (NMJ) as a model system and are focusing on identifying biological functions for components of a class of synapse-localized RNPs called RNA processing bodies (or "P bodies”). P bodies were initially identified as sites of 5' to 3' exonucleolytic messenger RNA (mRNA) decay but have since been found to be involved in both general and microRNA (miRNA)-mediated translational repression pathways. Distinct types of P bodies have recently been identified in fly and mammalian neurons that exhibit microtubule-based motorized movement towards distal synapses in response to chemical stimulation. These observations have lead to the development of two testable hypotheses: 1) neuronal P bodies are involved in the transport and/or translational repression of mRNAs that localize to distal dendrites and/or axon terminals; and 2) neuronal P bodies are required to transport components of the 5' to 3' mRNA degradation pathway to dendrites and/or axon terminals where they are involved in coupling mRNA translation to decay. Importantly, these hypotheses are not mutualy exclusive. Different flavors of neuronal P bodies may be involved in the control of each process.