The structure and expression of neuron-specific enolase gene

Transgenic mice expressing beta-galactosidase in mature neurons under neuron-specific enolase promoter control

To gain insights into transcription factors defining neuronal identity, we generated transgenic mice carrying a 1.8 kb rat neuron-specific enolase (NSE) promoter fragment fused to an E. coli lacZ gene. Four of seven transgenic families expressed transgene RNA in the nervous system but not in most other tissues. Histochemical analysis of adult brain from the two lines with highest lacZ mRNA levels showed neuron-specific, pan-neuronal beta-galactosidase activity. Developmental RNA and histochemical analyses showed parallel onset of transgene and endogenous NSE gene expression in various neuronal cell types, although the magnitude of NSE mRNA accumulation later in development was not matched by the transgene. These results suggest that cis-acting regulatory elements, subject to neuron-specific control, are located within 1.8 kb upstream from the NSE gene.

Structure of the human gene for alpha-enolase

In mammals there are at least three isoforms of the glycolytic enzyme enolase encoded by three similar genes: alpha, beta and gamma. In this report we describe the isolation and characterization of the human alpha-enolase locus. The gene appears to exist as a single copy in the haploid genome and is composed of 12 exons distributed over more than 18,000 bases. The structure of this gene has a high degree of similarity to that of the human and rat gamma-enolase genes, with identical positions for all the intron regions. Primer extension and S1 nuclease protection experiments indicate that transcription is initiated at multiple sites. The putative promoter region, like that of other house-keeping genes, lacks canonical TATA and CAAT boxes, is extremely G + C-rich and contains several potential SP1 binding sites. Furthermore, various sequences similar to known regulatory elements were detected.

The structure of the human gene encoding protein gene product 9.5 (PGP9.5), a neuron-specific ubiquitin C-terminal hydrolase

Database search using a bovine thymus ubiquitin C-terminal hydrolase sequence indicated 54% sequence identity with the abundant human neuron-specific protein gene product 9.5 (PGP9.5), which was then shown to possess the same activity [Wilkinson, Lee, Deshpande, Duerksen-Hughes, Boss & Pohl (1989) Science 246, 670-673]. A yeast counterpart of the enzyme is also known. The human PGP9.5 gene, described here, spans 10 kb, contains nine exons and displays 5' features some common to many genes and some common with neurofilament neuron-specific enolase and Thy-1-antigen gene 5' regions.

Nucleotide sequence and exon-intron organization of the human proacrosin gene

Acrosin is a serine proteinase and located in a zymogen form, proacrosin, in the acrosome of the sperm. As deduced from the cDNA sequences for human and boar proacrosin, the enzyme is synthesized as a preproenzyme, preproacrosin, which contains a hydrophobic leader sequence. Using cDNA clones as probes, we have isolated the gene coding for human proacrosin from a human leucocyte genomic library and a human cosmid library, respectively. The gene contains four introns between 0.2 kb--4.5 kb in length. Similar to other serine proteinases, the coding sequence of the preproacrosin gene is spread over all the five exons of the gene and the three activesite residues His, Asp and Ser are encoded by three different exons. According to the exon-intron structure, preproacrosin is suggested to be closely related to the serine proteinase subfamily containing trypsin and kallikrein. However, the light chain of proacrosin seems to be similar to that of chymotrypsin. The coding of the serine active-site residue together with the proacrosin-specific proline-rich domain in one exon, namely exon E5, let us assume that the nucleotide sequence for the proline-rich domain was generated during evolution by intron-exon transfer from a foreign gene with subsequent intron excision. By primer extension analysis, the transcription initiation site of the preproacrosin mRNA could be assigned to the residue C at -74 nucleotides upstream from the translation initiation codon ATG. In contrast to most other eucaryotic genes, including the known testis-specific genes, typical TATA and CAAT box sequences in convential distances from the 5' end of the transcription start site could not be evaluated in the proacrosin gene.

The human genome contains a single processed pseudogene for alpha enolase located on chromosome 1

We have isolated and characterized human genomic clones containing an alpha enolase pseudogene which lacks introns and has the hallmarks of having been generated by reverse transcription. Two in-frame termination codons renders its coding region incapable of producing a functional protein. An Alu-like sequence is present in the region homologous to the 3' untranslated of the alpha enolase mRNA. Comparison of the two sequences shows that the pseudogene diverged from its functional counterpart about 14 million years ago and interestingly it is the only alpha enolase pseudogene present in the human genome. Chromosomal mapping locates the processed pseudogene to human chromosome 1, the same chromosome where the functional gene has been mapped.

The gene for the muscle-specific enolase is on the short arm of human chromosome 17

The human gene encoding the muscle-specific beta-enolase has been isolated. The beta-enolase gene was mapped to chromosome 17 by analysis of a panel of rodent-human somatic cell hybrids. The gene was further localized to the short arm and tentatively to the region 17pter-p11 by analysis of cell hybrids and transfectant cell lines carrying different portions of chromosome 17.

Structure of mouse 2',3'-cyclic-nucleotide 3'-phosphodiesterase gene

The mouse 2',3'-cyclic-nucleotide 3'-phosphodiesterase gene was isolated from a mouse gene library. Restriction endonuclease mapping and DNA sequencing analysis revealed that this gene is about 6 kb long and is separated into three exons by two introns. The transcription initiation site was identified. The mouse cDNA of 2374 bp was obtained and used for the screening and analysis of the gene.

Cloning, expression and sequence homologies of cDNA for human gamma enolase

The nucleotide sequence of the human gamma-enolase mRNA was determined from recombinant cDNA clones. The sequence spans 2273 bp and includes the complete coding region of 1299 bp, a 5'-noncoding region of 74 bp and a 897-bp-long 3'-noncoding region containing a variant polyadenylation signal (ATTAAA). The deduced amino acid (aa) sequence is 433 aa long and shows a 97% similarity with rat gamma-enolase. Both the 5'- and 3'-untranslated regions are similar (82% and 68%, respectively) to the analogous regions of the rat gamma-enolase gene, suggesting that a strong selective pressure operates on noncoding segments of gamma-enolase mRNAs. The size of the gamma-enolase mRNA expressed in human brain is 2.4 kb. A crosshybridizing 1.5-kb message is detected in human skeletal muscle which may be derived from the beta-enolase-coding gene.

Progress toward human gene therapy

Current therapies for most human genetic diseases are inadequate. In response to the need for effective treatments, modern molecular genetics is providing tools for an unprecedented new approach to disease treatment through an attack directly on mutant genes. Recent results with several target organs and gene transfer techniques have led to broad medical and scientific acceptance of the feasibility of this "gene therapy" concept for disorders of the bone marrow, liver, and central nervous system; some kinds of cancer; and deficiencies of circulating enzymes, hormones, and coagulation factors. The most well-developed models involve alteration of mutant target genes by gene transfer with recombinant pathogenic viruses in order to express new genetic information and to correct disease phenotypes--the conversion of the swords of pathology into the plowshares of therapy.

The brain-specific gene for rat aldolase C possesses an unusual housekeeping-type promoter

A DNA fragment encompassing the first exon and about 750 bp of the 5'-flanking sequence has been isolated and sequenced. The gene has multiple start sites of transcription which are dispersed over about 200 bp. The promoter lacks TATA and CAAT boxes and is very G + C-rich, with putative binding sites for the transcriptional factors Sp1 and AP2. Similar features are shared with two other brain-specific genes encoding thy-1 antigen and gamma-enolase. The existence of a conserved block of similarity upstream of the human and rat aldolase C genes suggests that this region could be involved in tissue-specific expression whose mechanism seem to be, at least in part, transcriptional.

cDNA cloning and nucleotide sequence of rat muscle-specific enolase (beta beta enolase)

The nucleotide sequence of rat muscle-specific enolase cDNA was determined by sequencing three cDNA clones encoding this enolase isozyme. The nearly full-length cDNA consists of 13-bp 5'- and 84-bp 3'-noncoding regions and a poly(A) tail in addition to a 1302-bp coding region encoding a polypeptide composed of 434 amino acid residues. The deduced primary structure of this enolase isozyme is about 80% similar to those determined previously for rat neuron-specific and non-neuronal enolase isozymes. Southern blot analysis suggested strongly the existence of a single copy of the muscle-specific enolase gene per haploid genome. The mRNA for this enolase isozyme was detected in rat skeletal muscle on day 1 after birth and its level increased rapidly during 10-30 days after birth without any change in its size (1500 bases).