title: Effective induction of pblac1 laccase by copper ion in Polyporus brumalis ibrc05015.
abstract: Polyporus brumalis ibrc05015 is a strain capable of high laccase (Lac) production. Among several inducers, 0.25 mM copper was most effective for Lac production. One of the Lacs induced by copper was PbLac1, and its transcription was induced within 60 min after copper addition. The promoter region of pblac1 contained six putative metal response elements and one Ace1 consensus cis-element. We cloned the P. brumalis PbAce1 transcription factor, a homologue of Saccharomyces cerevisiae transcription factor Ace1, which regulates metallothionein genes in response to excess copper. PbAce1 complemented the function of Ace1 in an S. cerevisiae Δace strain. The conserved N-terminal copper-fist DNA binding domain of PbAce1 was required for complementation. In the PbAce1 complemented Δace1 strain, the pblac1 promoter was constitutively expressed at a high level, independent of copper concentration. PbAce1 has two Cys-rich repeat motifs (PbC1 and PbC2), which are similar to the Cys-rich repeat domain in metallothionein proteins, and are uniquely conserved in the C-terminal domain of basidiomycetous Ace1 sequences. These C-terminal domains could be involved in copper sensing and concentration-dependent Lac production in basidiomycetous fungi.
authors: Iwate Biotechnology Research Center, 22-174-4 Narita, Kitakami-shi, Iwate 024-0003, Japan. nakade_keiko@mail.tsumura.co.jp
authors: Keiko
authors: K
authors: Nakade
authors: Yuko
authors: Y
authors: Nakagawa
authors: Akira
authors: A
authors: Yano
authors: Naotake
authors: N
authors: Konno
authors: Toshitsugu
authors: T
authors: Sato
authors: Yuichi
authors: Y
authors: Sakamoto
mesh_terms: D003001:Cloning, Molecular; D003300:Copper / Q000378:metabolism / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D042845:Laccase / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D055492:Polyporus / Q000201:enzymology* / Q000235:genetics; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D014157:Transcription Factors; D003300:Copper; D042845:Laccase