RT Journal Article T1 AP-1 (bZIP) Transcription Factors as Potential Regulators of Metallothionein Gene Expression in Tetrahymena thermophila A1 Francisco Martínez, Patricia de A1 Amaro Torres, Francisco A1 Martín González, Ana María A1 Gutiérrez Fernández, Juan Carlos AB Metallothioneins (MT) are multi-stress proteins mainly involved in metal detoxification. MT gene expression is normally induced by a broad variety of stimulus and its gene expression regulation mainly occurs at a transcriptional level. Conserved motifs in the Tetrahymena thermophila MT promoters have been described. These motifs show a consensus sequence very similar to AP-1 sites, and bZIP type transcription factors might participate in the MT gene expression regulation. In this research work, we characterize four AP-1 transcription factors in each of four different analyzed Tetrahymena species, detecting a high conservation among them. Each AP-1 molecule has its counterpart in the other three Tetrahymena species. A comparative qRT-PCR analysis of these AP-1 genes have been carried out in different T. thermophila strains (including metal-adapted, knockout and/or knockdown strains among others), and under different metal-stress conditions (1 or 24 h Cd2+, Cu2+, or Pb2+ treatments). The possible interaction of these transcription factors with the conserved AP-1 motifs present in MT promoters has been corroborated by protein-DNA interaction experiments. Certain connection between the expression patterns of the bZIP and MT genes seems to exist. For the first time, and based on our findings, a possible gene expression regulation model including both AP-1 transcription factors and MT genes from the ciliate T. thermophila has been elaborated. PB University of Geneva SN 1664-8021 YR 2018 FD 2018-10-23 LK https://hdl.handle.net/20.500.14352/13502 UL https://hdl.handle.net/20.500.14352/13502 LA eng NO Ministerio de Economía y Competitividad (MINECO) NO Ministerio de Educación, Cultura y Deporte (MECD) DS Docta Complutense RD 8 jul 2025