title: Sequence analysis and gene expression of potential components of copper transport and homeostasis in Thalassiosira pseudonana.
abstract: Genes involved with many Fe functions and some Cu functions are annotated in the Thalassiosira pseudonana Hasle et Heimdal genome. Using bioinformatics, we performed a systematic Blastp search to obtain all relevant sequences and to select the most complete gene models for putative components of Cu acquisition and distribution. We identified homologs of high-affinity Cu transporters (CTR), Cu transporting P1B-type ATPases, Cu chaperones and ZIP transporters. The putative CTRs in T. pseudonana have the conserved CTR Cu-binding motifs and transmembrane domains, and their gene expression was down-regulated by a Cu addition to low Cu acclimated cultures. The sequences of some putative TpZIPs were similar to those of well-known Zn and Fe transporters. Cu addition affected the expression of some TpZIP genes, suggesting an interaction between Cu metabolism and that of Zn and/or Fe. For intracellular Cu distribution, we identified putative Cu transporting P1B-type ATPases, proposed to deliver Cu to the trans-Golgi or the secretory compartment, as well as putative Cu chaperones, proposed to deliver Cu to the mitochondrion. Their gene expression was down-regulated by a Cu addition, indicating that these putative intracellular Cu transporters and chaperones might redistribute Cu, allowing T. pseudonana to meet key metabolic needs under Cu deficiency.
authors.affiliation: Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4. Electronic address: jguo@mbari.org.
authors.forename: Jian
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4.
authors.forename: Beverley R
authors.initials: BR
authors.lastname: Green
authors.affiliation: Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4.
authors.forename: Maria T
authors.initials: MT
authors.lastname: Maldonado
mesh_terms: D019295:Computational Biology; D003300:Copper / Q000378:metabolism*; D017377:Diatoms / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006706:Homeostasis; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D003300:Copper
keywords: CTR; Cu; Cu chaperone; Fe; Zn.; transport