The human genome contains a single processed pseudogene for<i>a</i>enolase located on chromosome 1

Feo, Salvatore; Oliva, Daniele; Aricò, Beatrice; Barba, Giovanna; Calı̀, Larissa; Giallongo, Agata

doi:10.3109/10425179009041350

Cited by 8 publications

(8 citation statements)

References 15 publications

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“…All the genomic fragments which are detected by the full-length cDNA in Southern blots (Fig. 2) are either represented in this map or account (open circles) for the processed pseudogene [25]. These data strongly suggest that the functional locus, as well as the pseudogene, exist as a single copy in the human genome.…”

Section: Resultsmentioning

confidence: 67%

“…Another group of clones showed distinct BamHI hybridizing bands with the different probes and did not give a positive signal with the more 5' cDNA probe we used. Further analysis by nucleotide sequencing revealed that the first class of clones contained an intronless processed pseudogene for a-enolase [25], while clones within the other group contained sequences of the corresponding functional gene but all lacked the extreme 5' portion of the cDNA. In order to isolate recombinant phages encompassing the 5' end of the a-enolase gene the library was rescreened with a 199-bp PstI -Sac1 cDNA fragment covering the untranslated and the 5'-most coding region of the mRNA [3].…”

Section: Resultsmentioning

confidence: 99%

“…The several primer extention and S1 products are indicated by arrowheads and dots, respectively (B). The bigger arrowhead and dots are used to indicate the major products Southern blot analysis of human genomic DNA indicated that the intron-containing a-enolase gene is unique and, as supported by cloning data, the other related sequences present in the human genome account for a single processed pseudogene [25]. Both primer extension and S1 nuclease mapping established the existence of multiple start sites of transcription in the a-enolase gene.…”

Section: Isolution Ojthe L~uman A-enoluse Genementioning

confidence: 99%

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Structure of the human gene for α‐enolase

Giallongo¹,

Oliva

Calı̀

et al. 1990

European Journal of Biochemistry

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In mammals there are at least three isoforms of the glycolytic enzyme enolase encoded by three similar genes:a, p and y. In this report we describe the isolation and characterization of the human a-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 18000 bases. The structure of this gene has a high degree of similarity to that of the human and rat y-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 housekeeping 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 functional role of multiple enzyme isoforms and the regulatory mechanisms required for developmental and tissuespecific expression of these isoforms are still largely unknown. The glycolytic enzyme enolase (2-phospo-~-glycerate hydrolase) represents a suitable model for the study of these mechanisms. Three distinct isoforms of the enzyme, referred to as a or non-neuronal enolase, p or muscle-specific enolase and y or neuron-specific enolase are present in both avian and mammalian tissues [l]. The active enzyme is a homodimer of non-covalently linked subunits, each a, p and y subunit is encoded by a separate gene as previously proposed [2] and recently established by cDNA cloning in human [3-51, rat [6 -81, and mouse [9].While the y isoform is mainly detected in cells of neuronal origin and the p isoform is found in adult skeletal muscle, the a isoform is widely distributed among different tissues and is the major form of enolase present in the early stage of embryonic development. Isoform switch occurs along with terminal differentiation in neurons and skeletal muscle cells from the a-to the y-and p-enolase respectively [2, 10, 111. Although the isolated isoenzymes have been studied for many years and a substantial body of information on their biochemical, kinetic, and immunological properties [I21 as well as on the crystallographic structure [I31 has been collected, very little is known about the control of expression of the enolase genes. Beside the already mentioned differential expression during development and in various cell types, transcriptional induction of the a-enolase gene has been shown upon mitogenic stimulation of human peripheral-blood lymphocytes [3], as well as in quiescent rat fibroblast stimulated with growth factors or serum [14]. High levels of expression of the y isoform have been detected in many tumors of nonneuronal origin [5] suggesting lack of tissue-specific control in transformed cells. Furthermore, the finding that one of the two enolase isoenzymes of the budding yeast Saccharomyces cerevisiue may be involved in both thermal tolerance and growth control [15] and the identification of the lens structural prote...

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Section: Resultsmentioning

confidence: 67%

Section: Resultsmentioning

confidence: 99%

Section: Isolution Ojthe L~uman A-enoluse Genementioning

confidence: 99%

See 1 more Smart Citation

Structure of the human gene for α‐enolase

Giallongo¹,

Oliva

Calı̀

et al. 1990

European Journal of Biochemistry

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“…We decided to test this expectation on the human a-enolase pseudogene. This pseudogene has been sequenced, and both the active a-enolase gene and its processed pseudogene were found as single copies on human chromosome 1 (21). Using a published (22) rate for nucleotide substitutions in pseudogenes (5 x 10-9 per site per year), Feo et al (21) calculated that the human enolase pseudogene arose from its active progenitor about 14 million years (Myr) ago.…”

Section: Ct----------t------------------------------r----------------mentioning

confidence: 99%

“…This pseudogene has been sequenced, and both the active a-enolase gene and its processed pseudogene were found as single copies on human chromosome 1 (21). Using a published (22) rate for nucleotide substitutions in pseudogenes (5 x 10-9 per site per year), Feo et al (21) calculated that the human enolase pseudogene arose from its active progenitor about 14 million years (Myr) ago. If the calculated date is correct, one should find the pseudogene in the chimpanzee, which diverged from the hominid lineage 6-8 Myr ago, and in the gorilla, which diverged from the hominids and chimpanzees 7-10 Myr ago (23)(24)(25).…”

Section: Ct----------t------------------------------r----------------mentioning

confidence: 99%

The emergence of new DNA repeats and the divergence of primates.

Minghetti¹,

Dugaiczyk²

1993

Proc. Natl. Acad. Sci. U.S.A.

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We have identified four genetic novelties that are fixed in specific primate lineages and hence can serve as phylogenetic time markers. One Alu DNA repeat is present in the human lineage but is absent from the great apes. Another Alu DNA repeat is present in the gorilla lineage but is absent from the human, chimpanzee, and orangutan. A progenitor Xbal element is present in the human, chimpanzee, gorilla, and orangutan, but only in the human lineage did it give rise to a transposed progeny, Xba2. The saltatory appearance of Xba2 is an example of a one-time event in the evolutionary history of a species. The enolase pseudogene, known to be present as a single copy in the human, was found to be present in four other primates, including the baboon, an Old World monkey. Using the accepted value of 5 x 10-9 nucleotide substitutions per site per year as the evolutionary rate for pseudogenes, we calculated that the enolase pseudogene arose 14 million years ago. The calculated age for this pseudogene and its presence in the baboon are incongruent with each other, since Old World monkeys are considered to have diverged from the hominid Ilneage some 30 milion years ago. Thus the rate of evolution in the enolase pseudogene is only about 2.5 x 10-9 substitutions per site per year, or half the rate in other pseudogenes. It is concluded that rates of substitution vary between species, even for similar DNA elements such as pseudogenes. We submit that new DNA repeats arise in the genomes of species in irreversible and punctuated events and hence can be used as molecular time markers to decipher phylogenies.If it is true that evolution is punctuated with rapid changes and new species arise in saltatory events rather than by gradual accumulation ofpoint mutations (1), then it should be possible to identify at the molecular level the genetic events that underlie these evolutionary punctuations. For example, genomic rearrangements could change the timing of gene expression and thus profoundly affect development of the host; the new phenotype could sufficiently differ to start a new speciation process. Similarly, DNA rearrangements even in nonfunctional regions could disrupt meiotic chromosome pairing, leading to reproductive isolation of a previously interbreeding population. The specific genetic changes that punctuate the evolutionary process have yet to be identified, but perhaps the closest examples of such saltatory events in our genomes is the spreading of repetitive DNA elements. It therefore seems worthwhile to analyze these events in some detail, because they can provide us with genetic markers timing the evolutionary process.The most prominent among the various repetitive DNA elements are members ofthe Alu family. They are considered to be pseudogenes that are ancestrally related to 7SL RNA (2, 3) or 4.5S RNA (4), and it appears they arose from an as yet unidentified founder gene. They are specific to primate species, where they are found at an estimated 106 copies per genome (5-7). They have been known for some tim...

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Calculation and Verification of the Ages of Retroprocessed Pseudogenes

Friedberg

Rhoads

2000

Molecular Phylogenetics and Evolution

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The human genome contains a single processed pseudogene foraenolase located on chromosome 1

Cited by 8 publications

References 15 publications

Structure of the human gene for α‐enolase

Structure of the human gene for α‐enolase

The emergence of new DNA repeats and the divergence of primates.

Calculation and Verification of the Ages of Retroprocessed Pseudogenes

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