ribonucleotide enzyme that synthesizes by reverse transcription the terminal DNA units in telomeres.
An enzyme that catalyzes the lengthening of telomeres; the enzyme includes a molecule of RNA that serves as a template for new telomere segments. telomere The protective structure at each end of a eukaryotic chromosome. Specifically, the tandemly repetitive DNA ( see Repetitive DNA) at the end of the chromosome's DNA molecule. telophase[Gk. telos, end + phasis, form] The fourth and final stage of mitosis, during which daughter nuclei form at the two poles of a cell. Telophase usually occurs together with cytokinesis.
An enzyme composed of a catalytic protein component and an RNA template and that synthesizes the telomeric DNA at the ends of chromosomes. When active, telomerase can continually add to the length of the telomeres on the ends of chromosomes within a cell, thus conferring on that cell the ability to continue dividing past its normal lifespan.
an enzyme in eukaryotic cells that can add telomeres to the ends of chromosomes after they divide
a ribonucleoprotein complex that elongates telomeric DNA and appears to play an important role in cellular immortalization of cancers
An enzyme complex composed of an RNA subunit attached to protein. Telomerase is a reverse transcriptase that, when active, adds telomere to the ends of chromosomes. Telomerase acts in concert with telomere binding proteins. Telomerase is not easily detected in most somatic tissues of adult vertebrates. Telomerase is found in most tumor cells.
An enzyme that rebuilds telomeres. Telomerase is overexpressed in many cancer cells, and contributes to their immortality, or ability to divide endlessly.
an enzyme that maintains chromosome lengths by adding telomere repeats to the chromosomal ends.
A nuclear enzyme that is responsible for the extension and, therefore, maintenance of DNA sequences found at the end of chromosomes known as telomeres
tell-OM-er-ase An enzyme that extends chromosome tips using RNA as a template. 175
the enzyme, absent from most somatic cells but present in germline cells, that restores telomeres to their normal length.
enzyme that adds telomeric sequences to the telomeres and has been associated with cellular immortality.
Enzyme which reconstitutes telomeres.
A ribonucleoprotein complex that maintains the repeat sequence structures at the telomeric ends of chromosomes.
an enzyme that directs replication of telomeres at the end of DNA strands; a reverse transcriptase that carries its own RNA template; inactive in regular cells, but active in cancerous cells.
The enzyme that directs the replication of telomeres.
The enzyme that maintains the ends of eukaryotic chromosomes by synthesizing telomeric repeat sequences.
enzyme that is present and active in cells, so that they can divide without apparent limit. Telomerase replaces the missing repeated sequences of each telomere.
Protein responsible for maintaining structures called telomeres that are found at the ends of chromosomes. Telomeres are involved in cell ageing. They are thought to be involved in cancer development by allowing cells to live longer than normal.
makes the DNA ends of linear chromosomes; made up of an RNA portion and a protein portion, and probably dates back to the RNA world.
An enzyme that adds telomeric sequences to the ends of eukaryotic chromosomes.
a DNA polymerase that adds a short repeating sequence to the 3' strand at either end of a linear chromosomal DNA molecule, thereby creating a single-strand overhang. This permits DNA replication of the full length o f the chromosome.
(tee-LAW-mer-ase) An enzyme that adds telomeres to the ends of eukaryotic chromosomes, preventing the chromosome from shrinking during each cell division.
the enzyme which directs the replication of telomeres. This enzyme is inactive in normal cells but is rather active in cancerous cells. It has been shown recently that increased telomerase activity is not in and of itself the cause of cancerous growth. Note: A report in the January 1999 issue of Nature Genetics ("Telomerase expression in human somatic cells does not induce changes associated with a transformed phenotype" volume 21 no.1, pp 111 - 114) reported that cells immortalized with telomerase were more than 220 generations past their normal life span of 75 to 80 cell divisions, yet these cells remained young and vigorous and exhibited none of the characteristics associated with cancer cells, such as chromosome instability. In 1998 the same researchers reported in Science ("Extension of Life-Span by Introduction of Telomerase into Normal Human Cells") that telomerase introduced into human cells grown in the laboratory was sufficient to immortalize them.
An enzyme that adds repetitive units to the ends of linear chromosomes to prevent shortening after replication, using a special small RNA as a template.
An enzyme which, when expressed in a cell, causes re-lengthening of the telomeres. Telomerase is an unusual protein in that it contains an RNA template corresponding to the repeating telomere sequence TTAGGG. When telomerase is expressed, this template is used to rebuild the repeating sequences and re-lengthen the telomere. Every human cell contains the gene for telomerase, but this gene is normally repressed, so the cell makes little or no telomerase, and the telomeres continue to shorten with cell division
An enzyme with rather unusual properties that will only elongate telomeric DNA and not other DNA sequences.
Telomerase is an enzyme that adds specific DNA sequence repeats ("TTAGGG" in all vertebrates) to the 3' ("three prime") end of DNA strands in the telomere regions, which are found at the ends of eukaryotic chromosomes. The telomeres contain condensed DNA material, giving stability to the chromosomes. The enzyme is a reverse transcriptase that carries its own RNA molecule, which is used as a template when it elongates telomeres, which are shortened after each replication cycle.