Question

What is the role of telomerase in cells, i.e. what problem does it address? What are the components of telomerase? Hint – What type of a particle is it? How does it work? Why is telomerase active during embryonic development? What happens to telomerase gene expression in adult cells? How can telomerase act as a tumor promotor? Anything else you happen upon.

Answer 1

Telomerase is cellular reverse transcriptase that provides genomic stability in normal,immortal,tumor cells by maintaining integrity of chromosome ends,the telomeres.The telomerase addresses a problem of being associated with the majority of malignant human cancers.The components are functional RNA( hTR or hTERC) ,it serves as template for telomeric DNA synthesis and catalytic protein(hTERT) with reverse transcriptase activity.Telomerase is active during embryonic development because 1st few cells in zygote won't be able to develop into embryo without telomerase as cells replicate,telomeres shorten.In adult cells telomerase gene expression results in direct conversion of tumorigenic to normal human epithelial and fibroblast cells.2 highly recurrent mutations at 2 sites in the core promoter region of hTERT leads to mechanism for activation of telomerase in cancer cells, cancer cells achieve immortality by activating silent human TERT gene that encodes telomerase.