An unbiased in vivo screen reveals multiple transcription factors that control HPV E6-regulated hTERT in keratinocytes.
Activation of telomerase by human papillomavirus 16 (HPV16) E6 is a critical step for cell immortalization and transformation in human foreskin keratinocytes (HFKs). Multiple transcription factors have been identified as being involved in E6-induced hTERT expression. Here, we adapted an unbiased in vivo screen using a LacO-LacI system in human cells to discover hTERT promoter-interacting regulators. This approach allowed us to identify a novel hTERT repressor, Maz, which bound the hTERT promoter. E6 expression reduced Maz binding and correspondingly increased Sp1 binding at the hTERT promoter. Knockdown of Maz further increased histone acetylation, as well as hTERT expression in the presence of E6. Overall, these data indicate the utility of a novel screen for promoter-interacting and transcription-regulating proteins. These data also highlight multiple factors that normally regulate hTERT repression in HFKs, and therefore are targeted by E6 for hTERT expression.
Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA.
Mei
M
Xu
Rachel A
RA
Katzenellenbogen
Carla
C
Grandori
Denise A
DA
Galloway
D002472:Cell Transformation, Viral; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D054884:Host-Pathogen Interactions; D052162:Human papillomavirus 16 / Q000472:pathogenicity*; D006801:Humans; D015603:Keratinocytes / Q000821:virology*; D009856:Oncogene Proteins, Viral / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism*; D019098:Telomerase / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins; D014157:Transcription Factors; C509186:TERT protein, human; D019098:Telomerase; D001616:beta-Galactosidase
HPV E6; Keratinocytes; Maz; Sp1; hTERT