Plasma membrane H +-ATPase

Na, K -ATPase, a K ATPase Ca-+-ATPase, SR Ca" -ATPase, plasma membrane H -ATPase, yeast H" -ATPase, Neurospora... 

J. Guern, J. P. Renaudin, S. C. Brown, The compartmentation of secondary metabolites in plant cell cultures. Cell Culture and Somatic Cell Genetics of Plants. Vol. 4 (F, Constabel and 1. K. Vasil, eds.). Academic Press, San Diego, 1987, p. 43. A. L. Samuels, M. Fernando, and A. D. M. Glass, Immunofluorescent localization of plasma membrane H -ATPase in barley roots and effects of K nutrition. Plant Physiol. 99 1509 (1992). 

Further progress may derive from a more accurate definition of the chemical and physical properties of the humic substances present at the rhizosphere and how they interact with the root-cell apoplast and the plasma membrane. An interaction with the plasma membrane H -ATPase has already been observed however this master enzyme may not be the sole molecular target of humic compounds. Both lipids and proteins (e.g., carriers) could be involved in the regulation of ion uptake. It therefore seems necessary to investigate the action of humic compounds with molecular approaches in order to understand the regulatory aspects of the process and therefore estimate the importance of these molecules as modulators of the root-soil interaction. 

S. Santi, G. Locci, R. Pinton, S. Cesco, and Z. Varanini, Plasma membrane H -ATPase in maize roots induced for NO, uptake. Plant Physiol. 109 1271 (1995). 

Lecchi, S. Allen, K. E. Pardo, J. P Mason, A. B. Slayman, C. W. Conformational Changes of Yeast Plasma Membrane H+-ATPase during Activation by Glucose Role of Threonine-912 in the Carboxy-Terminal Tail. Biochemistry 2003, 44, 16624-16632. 

Baxter IR, Young JC, Armstrong G, Foster N, Bogenschutz N, Cordova T, Peer WA, Hazen SP, Murphy AS, Harper JF. 2005. A plasma membrane H + -ATPase is required for the formation of proanthocyanidins in the seed coat endothelium of... 

Studies have been conducted on the amount and functionality of plasma membrane H+ATPase. The central role of this enzyme in plant growth and mineral... 

Other evidence is reported in the paper of Canellas et al. (2002), in which a stimulation of the plasma membrane H+-ATPase activity took place, apparently associated with an ability to promote expression of this enzyme, as confirmed by western blot analysis. Using antibodies raised against H+- ATPase PMA2 isoform from Nicotianaplumbaginifolia Viv. (Morsomme et al., 1996), it was discovered that the amount of immunoreactive protein at the PM A locus (approximately 96 kD) increased almost threefold in the membrane vesicles isolated from maize roots treated with HA. 

Canellas, L. P., Olivares, E L., Okorokova-Faqanha, A. L., and Faqanha, A. R. (2002). Humic acids isolated from earthworm compost enhance root elongation, lateral root emergence, and plasma membrane H+-ATPase activity in maize roots. Plant Physiol. 130, 1951-1957. 

Morsomme, R, and Boutry, M. (2000). The plant plasma membrane H+-ATPase Structure, function and regulation. Biochim. Biophys. Acta 1465,1-16. 

Morsomme, R, d Exaerde, A. D., DeMeester, S.,Thines,D., Goffeau, A., and Boutry, M. (1996). Single point mutations in various domains of a plant plasma membrane H+-ATPase expressed in Saccharomyces cerevisiae increase H+- pumping and permit yeast growth at low pH. EMBO J. 15, 5513-5526. 

Palmgren, M. G. (1998). Proton gradients and plant growth role of the plasma membrane H+-ATPase. Adv. Bot. Res. 28,1-70. 

Pinton, R., Cesco, S., Iacoletti, G, Astolfi, S., and Varanini, Z. (1999a). Modulation of NO3 uptake by water-extractable humic substances Involvement of root plasma membrane H+ATPase. Plant Soil 215,155-161. 

Figure 9.3. Model for the action of humic substances (HS) on plasma membrane-bound targets of a root hair cell. Besides the well-known effects on plasma membrane H+-ATPase (P) and carriers (C) of mineral nutrients, the envisaged alteration of membrane lipid environment and the possible interaction with an hypothetical membrane receptor (R) for humic molecules which allows transduction of the signal for induction and expression of genes involved in nutrient uptake and root hair development are also presented.

Palmgren, M. G (2001). Plant plasma membrane H+-ATPases Powerhouses for nutrient uptake. Annu. Rev. Plant Physiol. Plant Mol. Biol. 52, 817-845. 

Santi, S.,Locci, G, Pinton,R., Cesco,S., and Varanini,Z. (1995). Plasma membrane H+-ATPase in maize roots induced for NO3 uptake. Plant Physiol. 109,1277-1283. 

Ghislain, M., Schlesser, A., Goffeau, A. (1987). Mutation of a conserved glycine residue modifies the vanadate sensitivity of the plasma membrane H+-ATPase from the schizosaccharomyces pombe. J. Biol. Chem. 262, 17549-17555. 

ATPase activity was also studied by Friebe et al. in 1997.17 They correlated the BOA and DIBOA effects on radicle elongation of Avena sativa seedlings with their effects on the activity of plasma membrane H+-ATPase from roots of Avena sativa cv. Jumbo and from Vida faba cv. Alfred. They hypothesized that an alteration in the plasma membrane ATPase activity could be the reason for an abnormal nutrient absorption in plants exposed to hydroxamic acids, because of the role that this enzyme plays in the ion gradient and, therefore, in the ionic transport through plasma membrane. The results of this experiment showed a strong inhibition in the activity of this enzyme in the plasma membrane of chloroplast and mitochondria when it was exposed to BOA and DIMBOA. This alteration implies early interactions with the assayed hydroxamic acids. 

Friebe, A., Roth, U., Kuck, P., Schnabl, H., and Schulz, M. 1997. Effects of 2,4-dihydroxy-1,4-benzoxazin-3-ones on the activity of plasma membrane H+-ATPase. Phytochemistry 44, 979-983... 

Xing, T., Higgins, VJ. and Blumwald, E., 1997, Identification of G proteins mediating fungal elicitor-induced dephosphorylation of host plasma membrane H+-ATPase. J. Exp. Bot. 48 229-237. 

ATP plays a central role in cellular maintenance both as a chemical for biosynthesis of macromolecules and as the major soirrce of energy for all cellular metabolism. ATP is utilized in numerous biochemical reactions including the eitric acid cycle, fatty acid oxidation, gluconeogenesis, glycolysis, and pyruvate dehydrogenase. ATP also drives ion transporters sueh as Ca -ATPase in the endoplasmic reticulum and plasma membranes, H+-ATPase in the lysosomal membrane, and Na+/K+-ATPase in the plasma membrane. Chemieal energy (30.5 kJ/mol) is released by the hydrolysis of ATP to adenosine diphosphate (ADP). 

M. Auer, G.A. Scarborough, and W. Kuhlbrandt. 1998. Threedimensional map of the plasma membrane H+-ATPase in the open conformation TVaTwre 392 840-843. (PubMed)... 

Based on a comprehensive shategy for the LC-MS characterizahon of membrane proteins [60], the analysis of in-vivo phosphorylated plasma membrane proteins from Arabidopsis thaliana was reported [40]. Phosphopephde isolahon was performed using SCX-IMAC, characterizahon with MALDI-MS and nano-LC-MS on a Q-TOF instrament. Six of the idenhfied sequences originated from different isoforms of plasma membrane H -ATPase, among which two new sites at the regulatory C-terminus. 

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