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Phosphorylation regulates the water channel activity of the seed-specific aquaporin alpha-TIP.
Maurel C
,
Kado RT
,
Guern J
,
Chrispeels MJ
.
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The vacuolar membrane protein alpha-TIP is a seed-specific protein of the Major Intrinsic Protein family. Expression of alpha-TIP in Xenopus oocytes conferred a 4- to 8-fold increase in the osmotic water permeability (Pf) of the oocyte plasma membrane, showing that alpha-TIP forms water channels and is thus a new aquaporin. alpha-TIP has three putative phosphorylation sites on the cytoplasmic side of the membrane (Ser7, Ser23 and Ser99), one of which (Ser7) has been shown to be phosphorylated. We present several lines of evidence that the activity of this aquaporin is regulated by phosphorylation. First, mutation of the putative phosphorylation sites in alpha-TIP (Ser7Ala, Ser23Ala and Ser99Ala) reduced the apparent water transport activity of alpha-TIP in oocytes, suggesting that phosphorylation of alpha-TIP occurs in the oocytes and participates in the control of water channel activity. Second, exposure of oocytes to the cAMP agonists 8-bromoadenosine 3',5'-cyclic monophosphate, forskolin and 3-isobutyl-1-methylxanthine, which stimulate endogenous protein kinase A (PKA), increased the water transport activity of alpha-TIP by 80-100% after 60 min. That the protein can be phosphorylated by PKA was demonstrated by phosphorylating alpha-TIP in isolated oocyte membranes with the bovine PKA catalytic subunit. Third, the integrity of the three sites at positions 7, 23 and 99 was necessary for the cAMP-dependent increase in the Pf of oocytes expressing alpha-TIP, as well as for in vitro phosphorylation of alpha-TIP. These findings demonstrate that the alpha-TIP water channel can be modulated via phosphorylation of Ser7, Ser23 and Ser99.(ABSTRACT TRUNCATED AT 250 WORDS)
Alexandre,
Hydrostatic and osmotic pressure activated channel in plant vacuole.
1991, Pubmed
Alexandre,
Hydrostatic and osmotic pressure activated channel in plant vacuole.
1991,
Pubmed
Anderberg,
Isolation of a wheat cDNA clone for an abscisic acid-inducible transcript with homology to protein kinases.
1992,
Pubmed
Brewster,
An osmosensing signal transduction pathway in yeast.
1993,
Pubmed
Chrispeels,
Aquaporins: the molecular basis of facilitated water movement through living plant cells?
1994,
Pubmed
Daniels,
The plasma membrane of Arabidopsis thaliana contains a mercury-insensitive aquaporin that is a homolog of the tonoplast water channel protein TIP.
1994,
Pubmed
,
Xenbase
DiGiovanni,
Regulation of collecting duct water channel expression by vasopressin in Brattleboro rat.
1994,
Pubmed
Echevarria,
Expression of multiple water channel activities in Xenopus oocytes injected with mRNA from rat kidney.
1993,
Pubmed
,
Xenbase
Ehring,
Phosphorylation modulates the voltage dependence of channels reconstituted from the major intrinsic protein of lens fiber membranes.
1992,
Pubmed
Fushimi,
Cloning and expression of apical membrane water channel of rat kidney collecting tubule.
1993,
Pubmed
,
Xenbase
Galcheva-Gargova,
An osmosensing signal transduction pathway in mammalian cells.
1994,
Pubmed
Guerrero,
Turgor-responsive gene transcription and RNA levels increase rapidly when pea shoots are wilted. Sequence and expression of three inducible genes.
1990,
Pubmed
Harris,
Current understanding of the cellular biology and molecular structure of the antidiuretic hormone-stimulated water transport pathway.
1991,
Pubmed
Höfte,
Vegetative and Seed-Specific Forms of Tonoplast Intrinsic Protein in the Vacuolar Membrane of Arabidopsis thaliana.
1992,
Pubmed
Homblé,
Coupling of water and potassium ions in K channels of the tonoplast of Chara.
1992,
Pubmed
Johnson,
An intrinsic tonoplast protein of protein storage vacuoles in seeds is structurally related to a bacterial solute transporter (GIpF).
1990,
Pubmed
Johnson,
An abundant, highly conserved tonoplast protein in seeds.
1989,
Pubmed
Johnson,
Tonoplast-bound protein kinase phosphorylates tonoplast intrinsic protein.
1992,
Pubmed
Kurosaki,
Stimulation of calcium influx and calcium cascade by cyclic AMP in cultured carrot cells.
1993,
Pubmed
Lampe,
Amino acid sequence of in vivo phosphorylation sites in the main intrinsic protein (MIP) of lens membranes.
1990,
Pubmed
Li,
Cyclic AMP stimulates K+ channel activity in mesophyll cells of Vicia faba L.
1994,
Pubmed
Ludevid,
The Expression Pattern of the Tonoplast Intrinsic Protein gamma-TIP in Arabidopsis thaliana Is Correlated with Cell Enlargement.
1992,
Pubmed
Maeshima,
Accumulation of Vacuolar H+-Pyrophosphatase and H+-ATPase during Reformation of the Central Vacuole in Germinating Pumpkin Seeds.
1994,
Pubmed
Maurel,
Functional characterization of the Escherichia coli glycerol facilitator, GlpF, in Xenopus oocytes.
1994,
Pubmed
,
Xenbase
Maurel,
The vacuolar membrane protein gamma-TIP creates water specific channels in Xenopus oocytes.
1993,
Pubmed
,
Xenbase
Miao,
Topology and phosphorylation of soybean nodulin-26, an intrinsic protein of the peribacteroid membrane.
1992,
Pubmed
Nielsen,
Cellular and subcellular immunolocalization of vasopressin-regulated water channel in rat kidney.
1993,
Pubmed
Pearson,
Protein kinase phosphorylation site sequences and consensus specificity motifs: tabulations.
1991,
Pubmed
Phillips,
Cloning of two gibberellin-regulated cDNAs from Arabidopsis thaliana by subtractive hybridization: expression of the tonoplast water channel, gamma-TIP, is increased by GA3.
1994,
Pubmed
Preston,
Membrane topology of aquaporin CHIP. Analysis of functional epitope-scanning mutants by vectorial proteolysis.
1994,
Pubmed
,
Xenbase
Preston,
Appearance of water channels in Xenopus oocytes expressing red cell CHIP28 protein.
1992,
Pubmed
,
Xenbase
Stanssens,
Efficient oligonucleotide-directed construction of mutations in expression vectors by the gapped duplex DNA method using alternating selectable markers.
1989,
Pubmed
Urao,
Two genes that encode Ca(2+)-dependent protein kinases are induced by drought and high-salt stresses in Arabidopsis thaliana.
1994,
Pubmed
Weaver,
Determination of the site of phosphorylation of nodulin 26 by the calcium-dependent protein kinase from soybean nodules.
1992,
Pubmed
