Details

Autor(en) / Beteiligte

• Sproles, Ashley E.
• Kirk, Nathan L.
• Kitchen, Sheila A.
• Oakley, Clinton A.
• Grossman, Arthur R.
• Weis, Virginia M.
• Davy, Simon K.

Titel

Phylogenetic characterization of transporter proteins in the cnidarian-dinoflagellate symbiosis

Ist Teil von

• Molecular phylogenetics and evolution, 2018-03, Vol.120, p.307-320

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •Conserved transporter proteins are involved in the cnidarian-dinoflagellate symbiosis.•GLUT protein homologs are predicted as the main transporters of glucose in cnidarians.•Aquaglyceroporins may facilitate the diffusion of glycerol across cnidarian membranes.•An upregulation of AMT proteins in Symbiodinium may have occurred as adaptations to the host environment. Metabolic exchange between cnidarians and their symbiotic dinoflagellates is central to maintaining their mutualistic relationship. Sugars are translocated to the host, while ammonium and nitrate are utilized by the dinoflagellates (Symbiodinium spp.). We investigated membrane protein sequences of each partner to identify potential transporter proteins that move sugars into cnidarian cells and nitrogen products into Symbiodinium cells. We examined the facilitated glucose transporters (GLUT), sodium/glucose cotransporters (SGLT), and aquaporin (AQP) channels in the cnidarian host as mechanisms for sugar uptake, and the ammonium and high-affinity nitrate transporters (AMT and NRT2, respectively) in the algal symbiont as mechanisms for nitrogen uptake. Homologous protein sequences were used for phylogenetic analysis and tertiary structure deductions. In cnidarians, we identified putative glucose transporters of the GLUT family and glycerol transporting AQP proteins, as well as sodium monocarboxylate transporters and sodium myo-inositol cotransporters homologous to SGLT proteins. We hypothesize that cnidarians use GLUT proteins as the primary mechanism for glucose uptake, while glycerol moves into cells by passive diffusion. We also identified putative AMT proteins in several Symbiodinium clades and putative NRT2 proteins only in a single clade. We further observed an upregulation of expressed putative AMT proteins in Symbiodinium, which may have emerged as an adaptation to conditions experienced inside the host cell. This study is the first to identify transporter sequences from a diversity of cnidarian species and Symbiodinium clades, which will be useful for future experimental analyses of the host-symbiont proteome and the nutritional exchange of Symbiodinium cells in hospite.