The yeast genome may harbor hypoxia response elements (HRE).
The hypoxia-inducible factor-1 (HIF-1) is a heterodimeric transcription factor activated when cells are submitted to hypoxia. The heterodimer is composed of two subunits, HIF-1alpha and the constitutively expressed HIF-1beta. During normoxia, HIF-1alpha is degraded by the 26S proteasome, but hypoxia causes HIF-1alpha to be stabilized, enter the nucleus and bind to HIF-1beta, thus forming the active complex. The complex then binds to the regulatory sequences of various genes involved in physiological and pathological processes. The specific regulatory sequence recognized by HIF-1 is the hypoxia response element (HRE) that has the consensus sequence 5'BRCGTGVBBB3'. Although the basic transcriptional regulation machinery is conserved between yeast and mammals, Saccharomyces cerevisiae does not express HIF-1 subunits. However, we hypothesized that baker's yeast has a protein analogous to HIF-1 which participates in the response to changes in oxygen levels by binding to HRE sequences. In this study we screened the yeast genome for HREs using probabilistic motif search tools. We described 24 yeast genes containing motifs with high probability of being HREs (p-value<0.1) and classified them according to biological function. Our results show that S. cerevisiae may harbor HREs and indicate that a transcription factor analogous to HIF-1 may exist in this organism.
Ferreira
Túlio César
TC
Laboratório de Biologia Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, 70910-900, Brazil.
Hertzberg
Libi
L
Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
Gassmann
Max
M
Institute of Veterinary Physiology, Vetsuisse Faculty and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 260, CH-8057, Zurich, Switzerland.
Campos
Élida Geralda
ÉG
Laboratório de Biologia Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, 70910-900, Brazil. Electronic address: elida@unb.br.
D001483:Base Sequence; D016678:Genome; D006801:Humans; D051793:Hypoxia-Inducible Factor 1 / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism; D020218:Response Elements / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D051793:Hypoxia-Inducible Factor 1; D046988:Proteasome Endopeptidase Complex