Supplemental Data Table S1

Supplemental dataTable S1. Water permeability of MIPs that transport non-aqua substrates.

NT: water permeability not tested; √: water permeability tested and the aquaporin shown to have at least some water activity; nd: osmotic water permeability not determined.

**Chaumont F, Barrieu F, Jung R, Chrispeels MJ (2000) Plasma membrane intrinsic proteins from maize cluster in two sequence subgroups with differential aquaporin activity. Plant Physiol 122: 1025-1034.

**Daniels MJ, Chaumont F, Mirkov TE, Chrispeels MJ(1996) Characterization of a new vacuolar membrane aquaporin sensitive to mercury at a unique site. Plant Cell 8:587–599.

**Kammerloher W, Fischer U, Piechottka GP, Schäffner AR (1994) Water channels in the plant plasma membrane cloned by immunoselection from a mammalian expression system. Plant J 6: 187-199.

**Katsuhara M, Akiyama Y, Koshio K, Shibasaka M, Kasamo K (2002) Functional analysis of water channels in barley roots. Plant Cell Physiol 43: 885-893.

**Maurel C, Reizer JU, Schroeder JI, Chrispeels MJ (1993) The vacuolar membrane protein -TIP creates water specific channels in Xenopus oocytes. EMBO J 12: 2241-3347.

Supplemental data Table S2. Chemical data on substrates transported by plant MIPs.

*The molecular radius and volume were calculated using the formula:

r =(Mr/ρNA*1/π*3/4)1/3 (adapted from Dordas and Brown, 2001**) where Mr is the molecular weight, ρ is the density in g/cm3 and NA is the Avogadro constant. The values for Mr and ρ were obtained from Lide (2008)**. na: data not available.

**Dordas C, Brown PH (2001) Evidence for channel mediated transport of boric acid in squash (Cucurbita pepo). Plant Soil 235: 95-103.

**Lide DR (2008) Handbook of Chemistry and Physics, Ed 89, CRC Press, Inc., Boca Raton, FL.

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Supplemental data Table S3. Examples of post-translational modifications reported for plant MIPs.

nd: non-aqua substrate(s) not determined.

** Temmei Y, Uchida S, Hoshino D, Kanzawa N, Kuwahara M, Sasaki S, Tsuchiya T (2005) Water channel activities of Mimosa pudica plasma membrane intrinsic proteins are regulated by direct interaction and phosphorylation. FEBS Lett 579: 4417-4422.

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Predicted Kinase

Supplemental data Table S4.Putative phosphorylation sites in MIPs with non-aqua transport functions

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The putative phosporylation sites and predicted kinases were predicted using NetPhos ( and NetPhosK ( The putative phosphorylation peptide sequences are shown with the predicted phosphorylated residues underlined. The location of the phosphorylation site [N-terminus (shown as N) or C- terminus (shown as C), Loop C, Loop E, Loop A, TM (transmembrane helix, with its number)] is given in parentheses. The experimentally proven phosphorylation sites are shown inbold. The residues corresponding to S262 in GmNOD26 and predicted as putative phosphorylation sites are highlighted in grey. The residues corresponding to S115 and S274 in SoPIP2;1 and predicted as putative phosphorylation sites are shown with an asterisk (*).

PKA: protein kinase A (cAMP-dependent protein kinase); PKC: protein kinase C; PKG: cyclic GMP-dependent protein kinase (protein kinase G); cdc2: cell division cycle 2 kinase (cdk1); p38MAPK: p38 mitogen-activated protein kinase; GSK3: glycogen synthase kinase 3;cdk5: cyclin-dependent kinase 5; CKI: casein kinase I; CKII: casein kinase II; RSK: ribosomal s6 kinase; DNAPK: DNA-dependent protein kinase.

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Supplemental data Table S5. Putative O-glycosylation sites in MIPs with non-aqua transport functions

The putative O-glycosylation sites were predicted using OGPET ( last accessed 16 November 2010). The putative glycosylation peptide sequences are shown, with the predicted glycosylated residues underlined. The location of the glycosylation site: N-terminus (shown as N) or Loop B (given in parentheses).

Supplemental data Table S6. Putative N-glycosylation sites in MIPs with non-aqua transport functions

The putative N-glycosylation sites were predicted using NetNGlyc 1.0 ( last accessed 16 November 2010). The putative glycosylation peptide sequences are shown, with the predicted glycosylated residues underlined. The location of the glycosylation site: N-terminus (shown as N) or C-terminus (shown as C), Loop A, Loop B, Loop C, Loop E, TM (transmembrane helix, with its number). *The potential score is the likelihood of the asparagine (N) being glycosylated

Supplemental data Table S7. Modelled representative MIPs and the characteristics of the templates.

aRepresentative MIP chosen to be modelled. bThe residue range of the representative MIP that could be modelled. cThe PDB ID ( of the template chosen using ‘automated modelling’ or ‘template identification’ on SWISS-MODEL ( dSequence identity of chosen representative aquaporin to chosen template. eSubstrate transported by the MIPs.

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Supplemental data Table S8. Structural characteristics of MIPs transporting non-aqua substrates*

*Alignments provided in Fig. S1. aa: amino acids. Dots represent the same value as the number immediately above.

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