Proteomic analyses of nucleus laminaris identified candidate targets of the fragile X mental retardation protein.
Hitomi SakanoDiego A R ZorioXiaoyu WangYing S TingWilliam S NobleMichael J MacCossEdwin W RubelYuan WangPublished in: The Journal of comparative neurology (2017)
The avian nucleus laminaris (NL) is a brainstem nucleus necessary for binaural processing, analogous in structure and function to the mammalian medial superior olive. In chickens (Gallus gallus), NL is a well-studied model system for activity-dependent neural plasticity. Its neurons have bipolar extension of dendrites, which receive segregated inputs from two ears and display rapid and compartment-specific reorganization in response to unilateral changes in auditory input. More recently, fragile X mental retardation protein (FMRP), an RNA-binding protein that regulates local protein translation, has been shown to be enriched in NL dendrites, suggesting its potential role in the structural dynamics of these dendrites. To explore the molecular role of FMRP in this nucleus, we performed proteomic analysis of NL, using micro laser capture and liquid chromatography tandem mass spectrometry. We identified 657 proteins, greatly represented in pathways involved in mitochondria, translation and metabolism, consistent with high levels of activity of NL neurons. Of these, 94 are potential FMRP targets, by comparative analysis with previously proposed FMRP targets in mammals. These proteins are enriched in pathways involved in cellular growth, cellular trafficking and transmembrane transport. Immunocytochemistry verified the dendritic localization of several proteins in NL. Furthermore, we confirmed the direct interaction of FMRP with one candidate, RhoC, by in vitro RNA binding assays. In summary, we provide a database of highly expressed proteins in NL and in particular a list of potential FMRP targets, with the goal of facilitating molecular characterization of FMRP signaling in future studies.
Keyphrases
- binding protein
- liquid chromatography tandem mass spectrometry
- spinal cord
- mental health
- protein protein
- ms ms
- risk assessment
- cell death
- high throughput
- high resolution
- working memory
- bipolar disorder
- spinal cord injury
- mass spectrometry
- single molecule
- small molecule
- emergency department
- adverse drug
- current status
- label free
- reactive oxygen species
- hearing loss
- dna binding