Molecular cloning of a neuron-specific transcript and its regulation during normal and aberrant cerebellar development.
AUTOR(ES)
Sangameswaran, L
RESUMO
PEP-19 is a brain-specific polypeptide whose levels increase dramatically during the late maturation of the rodent nervous system. By using immunocytochemistry, PEP-19 is shown to be localized to several regions of the central nervous system, notably cerebellum, thalamus caudate putamen, and olfactory bulb. We have isolated a 0.5-kilobase cDNA clone that encodes the entire PEP-19 protein sequence, making this one of the smallest primary transcripts and translation products ever identified in eukaryotes. The cDNA was used to investigate the developmental expression of PEP-19 in rodent brain. PEP-19 mRNA rises from low levels at embryonic day 17 of gestation in the rat to a plateau value by day 18 postpartum. This mirrored the levels of the protein determined by radioimmunoassay. Since the rise coincided with the formation of synaptic contacts onto Purkinje cells (a major site of PEP-19 expression), the hypothesis was tested that the activity and/or presence of afferent input modulated PEP-19 expression. Parallel fiber innervation was disrupted either by killing granule cells with the cytostatic agent methylazoxymethanol or by examining PEP-19 levels in cerebellar granuloprival mutant mice (reeler and weaver). The influence of climbing fiber input was assessed by either eliminating them with 3-acetylpyridine or stimulating them with harmaline in both neonatal and mature rats. None of the above altered PEP-19 gene expression in cerebellum, leading us to propose that the signals triggering the PEP-19 gene do not emanate from granule cells or neurons in the olivary nucleus. However, preliminary evidence suggests that PEP-19 is under posttranscriptional regulation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=297682Documentos Relacionados
- Identification and developmental regulation of a neuron-specific subunit of cytoplasmic dynein.
- Neuron-specific expression and physiological regulation of bovine vasopressin transgenes in mice.
- Survival motor neuron protein modulates neuron-specific apoptosis
- Cloning of the rat gene encoding choline acetyltransferase, a cholinergic neuron-specific marker.
- Molecular cloning and the nucleotide sequence of cDNA for neuron-specific enolase messenger RNA of rat brain.