Cloning of human neuronatin gene and its localization to chromosome-20q 11.2-12: the deduced protein is a novel "proteolipid'.

D Dou — 2007-12-07T16:37:25-00:00

Brain Res, Vol. 723, No. 1-2. (3 June 1996), pp. 8-22.

Human brain development is a continuum governed by differential gene expression. Therefore, we proceeded to identify genes selectively expressed in the developing brain. Using differential display and library screening, a novel rat cDNA, neuronatin, was identified and used to screen a human fetal brain cDNA library. Human neuronatin cDNA was isolated and sequenced. The cDNA was 1159 bp long and corresponded in size to the 1.25 kb message detected on Northern analysis. Neuronatin mRNA was selectively expressed in human brain during fetal development, but became repressed in adulthood. When studied in the rat, neuronatin mRNA first appeared at mid-gestation in association with the onset of neurogenesis, becoming most pronounced later in development when neuroepithelial proliferation and neuroblast commitment are manifest, and declined postnatally coinciding with the completion of neurogenesis. The deduced protein has two distinct domains, a hydrophobic N-terminal and basic C-terminal rich in arginine residues. Both the amino acid sequence and secondary structure of this amphipathic polypeptide exhibited homology to PMP1 and phospholamban, members of the "proteolipid' class of proteins which function as regulatory subunits of membrane channels. The neuronatin gene, 3973 bases long, contains in its 5'-flanking region a neural restrictive silencer element which may govern neuron-specific expression. Based on screening a somatic cell hybrid panel, neuronatin gene was assigned to chromosome-20. And, using deletion constructs of chromosome-20 and fluorescence in situ hybridization, neuronatin was localized to chromosome-20q11.2-12. In conclusion, neuronatin is a novel human gene that is developmentally regulated and expressed in the brain. The deduced protein is a proteolipid that may function as a unique regulator of ion channels during brain development. The definitive localization of neuronatin to human chromosome 20q11.2-12 provides the basis to investigate this gene as a candidate in neuro-developmental diseases that may also map to this region.

Neuronatin mRNA: alternatively spliced forms of a novel brain-specific mammalian developmental gene.

R Joseph — 2007-12-06T17:47:00-00:00

Brain Res, Vol. 690, No. 1. (28 August 1995), pp. 92-98.

Neurogenesis begins with the closure of the neural tube around mid gestation and continues in the rat for about two weeks postnatally. Therefore, we investigated the role of neuronatin, a novel cDNA that we cloned from neonatal rat brain (Joseph et al., Biochem. Biophys. Res. Commun., 201 (1994) 1227-1234), in brain development. Further studies described in the present manuscript, lead to the identification of two alternatively spliced forms of neuronatin mRNA, alpha and beta, with the same open reading frame. Neuronatin-alpha encoded a novel protein of 81 aa, and the beta-form encoded 54 aa. Both forms were identical, except that the alpha-form had an additional 81 bp sequence inserted into the middle of the coding region. On Northern analyses, neuronatin mRNA was relatively selective for the brain. It first appeared at E11-14, a time when the neural tube has closed and neuroepithelial proliferation initiated, became pronounced at E16-19 with a surge in neurogenesis, and declined postnatally to adult levels with the completion of neurogenesis. In order to determine whether there were other forms of neuronatin mRNA, and to study the expression of the alpha and beta forms separately during development, reverse transcriptase-polymerase chain reaction was carried out using primers flanking the coding region of the alpha and beta forms. The RT-PCR results clearly indicated that there were only two forms of neuronatin. The beta-form first appeared at E11-14, whereas the alpha-form was present even earlier at E7-10. Together, these findings indicate that the two forms of neuronatin mRNA are regulated differently during brain development.(ABSTRACT TRUNCATED AT 250 WORDS)

CiteULike: rschulz's Dou

Cloning of human neuronatin gene and its localization to chromosome-20q 11.2-12: the deduced protein is a novel "proteolipid'.

Neuronatin mRNA: alternatively spliced forms of a novel brain-specific mammalian developmental gene.