Funds are requested to purchase the Finnigan LCQ(DECA) Quadrupole Ion Trap Mass Spectrometer. As the first mass spectrometer at the institution, it will have an enormous impact in its expansion of potential areas for investigation. The proposed use of the instrument by ten major users covers a wide range of medically oriented research areas. These may be summarized as follows: Muscle-related projects include the study of a potential role for methylation of myosin (User 1), and regulatory protein/DNA interactions in skeletal muscle development and cardiogenesis (User 2). Projects relating to transcription and translation in general are featured in three projects: the interaction of elongation arrest factors GreA and GreB with RNA polymerase (User 3), the characterization of interactions between model mRNAs, RNA-binding eukaryotic initiation factions and ribosomal proteins (User 4), and characterization of the interactions between RNA polymerase, the DNA template, and nascent RNA during transcription (User 5). Cell signaling projects appear in a study of the origin, phosphorylation state and function of a newly described form of brain protein kinase C (User 6), in an analysis of the phosphorylation state of adenylyl cyclase following chronic exposure to morphine (User 7), and in a phosphorylation study of the action and regulation of RAN1 kinase during the decision by yeast cells to select meiosis or mitosis (User 8). A study of NMDA receptor-regulated neurotransmitter release in hippocampus and striatum will combine single-cell recording and microdialysis techniques in freely behaving animal (User 9). The effects of developmental cocaine exposure on neuropeptide levels in selected brain regions of rats will be investigated by User 10. The application is supported by the recent recruitment of a faculty member with extensive experience in mass spectrometry.