Analysis of Porphyra Membrane Transporters Demonstrates Gene Transfer among Photosynthetic Eukaryotes and Numerous Sodium-Coupled Transport Systems

• Published in: Plant physiology (Bethesda) Vol. 158; no. 4; pp. 2001 - 2012
• Main Authors: Chan, Cheong Xin, Zäuner, Simone, Wheeler, Glen, Grossman, Arthur R., Prochnik, Simon E., Blouin, Nicolas A., Zhuang, Yunyun, Benning, Christoph, Berg, Gry Mine, Yarish, Charles, Eriksen, Renée L., Klein, Anita S., Lin, Senjie, Levine, Ira, Brawley, Susan H., Bhattacharya, Debashish
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.04.2012
• Subjects: Algae; Aquaporins - metabolism; Bangiophyceae; Biological and medical sciences; Biological Transport - genetics; Calcium Signaling - genetics; Cell membranes; Eukaryota - genetics; Evolution; Evolution, Molecular; Expressed Sequence Tags; Fresh Water; Fundamental and applied biological sciences. Psychology; Gene Transfer, Horizontal - genetics; Genes; GENETICS, GENOMICS, AND MOLECULAR EVOLUTION; Genomes; Green algae; Ion Transport - genetics; Lipid Metabolism - genetics; Membrane transport proteins; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Molecular Sequence Data; Nitrates - metabolism; Photosynthesis - genetics; Phylogeny; Plant physiology and development; Plantae; Plants; Plastids; Porphyra - genetics; Porphyra purpurea; Porphyra umbilicalis; Quaternary Ammonium Compounds - metabolism; Red algae; Rhodophyta; Seawater; Sodium - metabolism; Stramenopiles; Transcriptome - genetics; Rhodophyta; Sodium; Plant physiology; Algae; Porphyra; Membrane; Marine alga; Photosynthesis; Transport; Bangiophyceae; Genetic transfer
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.112.193896

Membrane transporters play a central role in many cellular processes that rely on the movement of ions and organic molecules between the environment and the cell, and between cellular compartments. Transporters have been well characterized in plants and green algae, but little is known about transporters or their evolutionary histories in the red algae. Here we examined 482 expressed sequence tag contigs that encode putative membrane transporters in the economically important red seaweed Porphyra (Bangiophyceae, Rhodophyta). These contigs are part of a comprehensive transcriptome dataset from Porphyra utnbilicalis and Porphyra purpurea. Using phylogenomics, we identified 30 trees that support the expected monophyly of red and green algae/plants (i.e. the Plantae hypothesis) and 19 expressed sequence tag contigs that show evidence of endosymbiotic/horizontal gene transfer involving stramenopiles. The majority (77%) of analyzed contigs encode transporters with unresolved phylogenies, demonstrating the difficulty in resolving the evolutionary history of genes. We observed molecular features of many sodium-coupled transport systems in marine algae, and the potential for coregulation of Porphyra transporter genes that are associated with fatty acid biosynthesis and intracellular lipid trafficking. Although both the tissue-specific and subcellular locations of the encoded proteins require further investigation, our study provides red algal gene candidates associated with transport functions and novel insights into the biology and evolution of these transporters.