title: Low-affinity copper transporter CTR2 is regulated by copper-sensing transcription factor Mac1p in Saccharomyces cerevisiae.
abstract: Copper is an indispensable metal for life. For convenience of genetic manipulation and sharing similar metabolic pathway of metals with mammalian cells, the yeast Saccharomyces cerevisiae is widely used for metal homeostasis studies. Storage and mobilization of copper ions in yeast vacuoles or mammalian lysosomes are important for cells to avoid their toxicity and elevate their utility. Though regulation of other genes involved in copper homeostasis is well understood, the regulation of gene encoding low-affinity copper transporter Ctr2p, which mediates mobilization of vacuolar or lysosomal stored copper ions, is still unclear. In this study, we found that copper depletion can upregulate yeast CTR2 gene transcription while copper overload downregulate it. The copper-depletion induced CTR2 transcription can be abrogated by genetic deletion of copper-sensing transcription factor Mac1p. Though absent of consensus Mac1p binding sequences, CTR2 promoter region is demonstrated to be occupied by Mac1p, according to our results of chromatin immunoprecipitation (ChIP) assay. Overexpression of Mac1p can upregulate CTR2 transcription and partially complement the growth defect of copper-deficient yeast strain. Taken together, our results suggest that Mac1p can activate the expression of vacuolar copper transporter Ctr2p in response to copper deficiency, resulting in yeast resistance to copper starvation.
authors.affiliation: Center for Growth, Metabolism and Aging, College of Life Sciences, Sichuan University, Chengdu 610064, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Liu
authors.forename: Jin
authors.initials: J
authors.lastname: Qi
authors.forename: Zemin
authors.initials: Z
authors.lastname: Yang
authors.forename: Lianghong
authors.initials: L
authors.lastname: Peng
authors.forename: Chenghua
authors.initials: C
authors.lastname: Li
mesh_terms: D027682:Cation Transport Proteins / Q000235:genetics*; D003300:Copper / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D000080083:SLC31 Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D027682:Cation Transport Proteins; C497350:Ctr2 protein, S cerevisiae; C084954:MAC1 protein, S cerevisiae; D009687:Nuclear Proteins; D012333:RNA, Messenger; D000080083:SLC31 Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D003300:Copper