title: Inhibition of telomerase activity by reduction of poly(ADP-ribosyl)ation of TERT and TEP1/TP1 expression in HeLa cells with knocked down poly(ADP-ribose) polymerase-1 (PARP-1) gene.
abstract: Inhibitors of poly(ADP-ribose) polymerase (PARP) have been shown to reduce the telomerase activity in cultured cells. To find out the specific member of the PARP family, which participates in the regulation of telomerase activity, in the present investigation, we knocked down the PARP-1 gene by siRNA in HeLa cells and studied the telomerase activity. Reduction of expression of PARP-1 by siRNA increased cellular NAD(+) level and decreased general poly(ADP-ribosyl)ation of proteins. Telomerase activity decreased in cells with knocked down PARP-1 gene. Besides, we observed that telomerase reverse transcriptase (hTERT) was poly(ADP-ribosyl)ated in HeLa cells and such modification was decreased in cells with reduced PARP-1 expression. In addition, the expression of telomerase-associated protein 1 (TEP1/TP1) subunit of human telomerase holoenzyme reduced significantly in PARP-1 knock down HeLa cells. Thus, PARP-1 modulates the telomerase activity by altering poly(ADP-ribosyl)ation of TERT and/or the expression of TEP1/TP1.
authors.affiliation: Department of Biochemistry & Biophysics, University of Kalyani, Kalyani, Nadia 741235, India.
authors.forename: Utpal
authors.initials: U
authors.lastname: Ghosh
authors.forename: Nilanjana
authors.initials: N
authors.lastname: Das
authors.forename: Nitai P
authors.initials: NP
authors.lastname: Bhattacharyya
mesh_terms: D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D015536:Down-Regulation; D006367:HeLa Cells; D006801:Humans; D000071137:Poly (ADP-Ribose) Polymerase-1; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D016601:RNA-Binding Proteins; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014162:Transfection
chemical_list: D002352:Carrier Proteins; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C104342:TEP1 protein, human; D011064:Poly Adenosine Diphosphate Ribose; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; C509186:TERT protein, human; D019098:Telomerase