Program in Gene Function and Expression
Medical Subject Headings
Animals; Apoptosis; Cell Membrane; Databases, Nucleic Acid; Drosophila Proteins; Drosophila melanogaster; Exocytosis; Gene Expression Regulation, Enzymologic; Immunity, Innate; Larva; Membrane Proteins; Microscopy, Electron, Transmission; Molecular Sequence Data; Mutation; Neuromuscular Junction; Neurotransmitter Agents; Phospholipid Transfer Proteins; Phospholipids; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Synaptic Membranes; Synaptic Transmission; Synaptic Vesicles
Genetics and Genomics
Scramblases are a family of single-pass plasma membrane proteins, identified by their purported ability to scramble phospholipids across the two layers of plasma membrane isolated from platelets and red blood cells. However, their true in vivo role has yet to be elucidated. We report the generation and isolation of null mutants of two Scramblases identified in Drosophila melanogaster. We demonstrate that flies lacking either or both of these Scramblases are not compromised in vivo in processes requiring scrambling of phospholipids. Instead, we show that D. melanogaster lacking both Scramblases have more vesicles and display enhanced recruitment from a reserve pool of vesicles and increased neurotransmitter secretion at the larval neuromuscular synapses. These defects are corrected by the introduction of a genomic copy of the Scramb 1 gene. The lack of phenotypes related to failure of scrambling and the neurophysiological analysis lead us to propose that Scramblases play a modulatory role in the process of neurotransmission.
Rights and Permissions
Citation: J Cell Biol. 2006 Apr 10;173(1):69-82. Link to article on publisher's site