| Protein isoaspartyl methyltransferase (PIMT) activity is highly expressed in mouse brain and its absence in transgenic knockout mice produces fatal seizures. As a preliminary step to identifying cellular patterns of PIMT expression in brain, a set of neuron-specific and glial-specific expression clones were constructed to serve as markers for specific cell types. Complementary cDNA clones containing partial coding sequences for S100{dollar}beta{dollar} and glial fibrillary acidic protein (GFAP) were constructed to provide glial-specific markers, and a synapsin clone was constructed to serve as a neuronal marker. A similar construct containing the coding sequence for PIMT was used to construct antisense biotin-labeled transcripts which were successfully used to detect PIMT transcripts in samples containing 10 {dollar}mu{dollar}g of mouse brain total RNA. The neuronal and glial specific markers developed here, representing more abundant proteins, will be useful for distinguishing neural and glial expression of PIMT transcript. |
