Recombinant Mouse Telomerase reverse transcriptase (Tert), partial

Function

Telomerase is a ribonucleoprotein enzyme essential for the replication of chromosome termini in most eukaryotes. Active in progenitor and cancer cells. Inactive, or very low activity, in normal somatic cells. Catalytic component of the teleromerase holoenzyme complex whose main activity is the elongation of telomeres by acting as a reverse transcriptase that adds simple sequence repeats to chromosome ends by copying a template sequence within the RNA component of the enzyme. Catalyzes the RNA-dependent extension of 3'-chromosomal termini with the 6-nucleotide telomeric repeat unit, 5'-TTAGGG-3'. The catalytic cycle involves primer binding, primer extension and release of product once the template boundary has been reached or nascent product translocation followed by further extension. More active on substrates containing 2 or 3 telomeric repeats. Telomerase activity is regulated by a number of factors including telomerase complex-associated proteins, chaperones and polypeptide modifiers. Modulates Wnt signaling. Plays important roles in aging and antiapoptosis (By similarity)

Subcellular Location

Nucleus, nucleolus; Nucleus, nucleoplasm; Nucleus; Chromosome, telomere; Cytoplasm; Nucleus, PML body

Tissue Specificity

High activity in intestine, liver and testis, moderate in lung, very low in muscle, heart and brain

Subunit

Catalytic component of the telomerase holoenzyme complex composed of one molecule of TERT, one molecule of WRAP53/TCAB1, two molecules of H/ACA ribonucleoprotein complex subunits DKC1, NOP10, NHP2 and GAR1, and a telomerase RNA template component (TERC). The telomerase holoenzyme complex is associated with TEP1, SMG6/EST1A and POT1. The molecular chaperone HSP90/P23 complex is required for correct assembly and stabilization of the active telomerase. Interacts directly with HSP90A and PTGES3. Interacts with HSPA1A; the interaction occurs in the absence of TERC and dissociates once the complex has formed. Interacts with RAN; the interaction promotes nuclear export of TERT. Interacts with XPO1. Interacts with PTPN11; the interaction retains TERT in the nucleus. Interacts with NCL (via RRM1 and C-terminal RRM4/Arg/Gly-rich domains); the interaction is important for nucleolar localization of TERT (By similarity). Interacts with SMARCA4 (via the bromodomain); the interaction regulates Wnt-mediated signaling (PubMed:19571879). Interacts with MCRS1 (isoform MCRS2); the interaction inhibits in vitro telomerase activity (By similarity). Interacts with PIF1; the interaction has no effect on the elongation activity of TERT (PubMed:17130244). Interacts with PML; the interaction recruits TERT to PML bodies and inhibits telomerase activity (By similarity). Interacts with GNL3L (PubMed:19487455). Interacts with isoform 1 and isoform 2 of NVL (By similarity). Interacts with DHX36 (By similarity). Interacts with ATF7 (By similarity)

• Greenberg R.A. et al. Expression of mouse telomerase reverse transcriptase during development, differentiation and proliferation. — Oncogene (1998)
• Martin-Rivera L. et al. Expression of mouse telomerase catalytic subunit in embryos and adult tissues. — Proc. Natl. Acad. Sci. U.S.A. (1998)
• Wong S.C. et al. Cloning of rat telomerase catalytic subunit functional domains, reconstitution of telomerase activity and enzymatic profile of pig and chicken tissues. — Life Sci. (2003)
• Drissi R. et al. Partial sequence of Mus musculus telomerase catalytic subunit homolog. (OCT-)
• Snow B.E. et al. Murine Pif1 interacts with telomerase and is dispensable for telomere function in vivo. — Mol. Cell. Biol. (2007)
• Zhu Q. et al. GNL3L stabilizes the TRF1 complex and promotes mitotic transition. — J. Cell Biol. (2009)
• Park J.I. et al. Telomerase modulates Wnt signalling by association with target gene chromatin. — Nature (2009)