Open AccessIdentification of the Cadmium-Inducible Hansenula polymorpha SEO1 Gene Promoter by Transcriptome Analysis and Its Application to Whole-Cell Heavy-Metal Detection Systems
Author(s) -
Jeong-Nam Park,
Min Jeong Sohn,
Doo-Byoung Oh,
Ohsuk Kwon,
Shin Hyung Rhee,
Cheol-Goo Hur,
Sang Yup Lee,
Gerd Gellissen,
Hyun Ah Kang
Publication year - 2007
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.00863-07
Subject(s) - promoter , biology , gene , microbiology and biotechnology , reporter gene , green fluorescent protein , gene expression , saccharomyces cerevisiae , genetics
The genomewide gene expression profiling of the methylotrophic yeastHansenula polymorpha exposed to cadmium (Cd) allowed us to identify novel genes responsive to Cd treatment. To select genes whose promoters can be useful for construction of a cellular Cd biosensor, we further analyzed a set ofH. polymorpha genes that exhibited >6-fold induction upon treatment with 300 μM Cd for 2 h. The putative promoters, about 1,000-bp upstream fragments, of these genes were fused with the yeast-enhanced green fluorescence protein (GFP) gene. The resultant reporter cassettes were introduced intoH. polymorpha to evaluate promoter strength and specificity. The promoter derived from theH. polymorpha SEO1 gene (HpSEO1 ) was shown to drive most strongly the expression of GFP upon Cd treatment among the tested promoters. The Cd-inducible activity was retained in the 500-bp deletion fragment of the HpSEO1 promoter but was abolished in the further truncated 250-bp fragment. The 500-bp HpSEO1 promoter directed specific expression of GFP upon exposure to Cd in a dose-dependent manner, with Cd detection ranging from 1 to 900 μM. Comparative analysis of theSaccharomyces cerevisiae SEO1 (ScSEO1 ) promoter revealed that the ScSEO1 promoter has a broader specificity for heavy metals and is responsive to arsenic and mercury in addition to Cd. Our data demonstrate the potential use of the HpSEO1 promoter as a bioelement in whole-cell biosensors to monitor heavy metal contamination, particularly Cd.