asmi
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What is the role of telomerase enzyme ? what is its importance ?
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| kris2c
Forum Senior
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Telomerases
(a ribonuclear protein that synthesizes the TELOMERES de novo)
** Finishes the ends (adds hexameric TTAGGG nucleotide repeats)
of Eukaryotic linear chromosomal DNAs to compensate for losses
that occur with each round of DNA replication.
** It's a Key Ez in Embryogenesis :icon_bounce:
** Extremely ↑↑↑ activity in cancer
Is that correct ? :icon_scratch:
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Kris2c
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| krsma
Forum Elite
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Telomeres:
-repetitive sequences @ ends of linear DNA in Eukaryotes
-located at 5' ends
-shortened w/ each rounds of replication --> contributing to aging of cells
-eventually telomeres become so short that chromosomes cannot function properly
Telomerase:
-basically same as what kris2c stated (you're right kris2c)
-it's an enzyme basically used to maintain telomeres that would otherwise be lost during replication
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| usmleasr
Forum Guru
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telomerase is itself not a ribonucleo protein..it is an enzyme with reverse transcriptase activity...others are correct..it synthesizes DNA from RNA primer ..which is not replicated other wise at 5' end...
correct me if i am wrong :|
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| kris2c
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Incomplete replication of chromosome ends (telomere shortening):
Telomeres are short repeated sequences of DNA (TTAGGG) that compose the linear ends of chromosomes and are important in ensuring the complete replication of chromosome ends and protecting chromosomal termini from fusion and degradation.
The sequences are formed by
a specialized RIBONUCLEOPROTEIN: TELOMERASE;
an Enzyme that stabilizes telomere length by adding to the ends of chromosomes.
The activity of telomerase is repressed by regulatory proteins, which restrict telomere elongation, thus providing a length sensing mechanism.
Robbins Pathologic Basis of Disease, 6th ed.
:-k
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Kris2c
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| asmi
Forum Hero
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thanks to all of you...
Teleomerase composition = short RNA template + hTRT .
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| asmi
Forum Hero
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and yes as you said ...immortality of malignant cells is due to this enzyme.
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| Malaysian
Forum Guru
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Thanks.
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| santaclara
Forum Elite
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hey usmleasr
do u mean that telomerase synthesizes DNA from RNA primer?
idon't think so b/c i think primase synthesize the RNA PRIMERS.
IF WRONG CORRECT ME.
THANX.
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