proteomic and phosphoproteomic analysis of Oryza sativa plasma membrane and vacuolar membrane

• Published in: The Plant journal : for cell and molecular biology Vol. 56; no. 1; pp. 146 - 156
• Main Authors: Whiteman, Sally-Anne, Nühse, Thomas S, Ashford, David A, Sanders, Dale, Maathuis, Frans JM
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.10.2008; Blackwell Publishing Ltd; Blackwell Science
• Subjects: ABC transporters; Amino Acid Sequence; Ammonium; antiporters; aquaporins; Biological and medical sciences; Botany; calcium; Cell Membrane; Cell Membrane - chemistry; Cell membranes. Ionic channels. Membrane pores; Cell structures and functions; chemistry; Chromatography, Liquid; Fundamental and applied biological sciences. Psychology; genes; genetics; membrane transport; Membrane Transport Proteins; Membrane Transport Proteins - chemistry; Membranes; Molecular and cellular biology; Molecular Sequence Data; Oryza; Oryza - chemistry; Oryza - genetics; Oryza sativa; Phosphoproteins; Phosphoproteins - chemistry; phosphoproteomics; Phosphorylation; Plant Proteins; Plant Proteins - chemistry; Plant Roots; Plant Roots - chemistry; Plant Roots - genetics; Plant Shoots; Plant Shoots - chemistry; Plant Shoots - genetics; plasma membrane; Proteins; Proteome; Proteomics; proton pump; Pumps; Rice; Roots; Shoots; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sugar; sugars; Tandem Mass Spectrometry; Tissues; vacuoles; Vacuoles - chemistry; phosphoproteomics; Monocotyledones; Root; rice; Oryza sativa; Gene; Gramineae; Membrane transport; Angiospermae; Plasma membrane; Proteomics; Above ground plant part; Spermatophyta; Aquaporin
• ISSN: 0960-7412; 1365-313X; 1365-313X
• DOI: 10.1111/j.1365-313x.2008.03578.x

Proteomic and phosphoproteomic analyses of rice shoot and root tonoplast-enriched and plasma membrane-enriched membrane fractions were carried out to look at tissue-specific expression, and to identify putative regulatory sites of membrane transport proteins. Around 90 unique membrane proteins were identified, which included primary and secondary transporters, ion channels and aquaporins. Primary H⁺ pumps from the AHA family showed little isoform specificity in their tissue expression pattern, whereas specific isoforms of the Ca²⁺ pump ECA/ACA family were expressed in root and shoot tissues. Several ABC transporters were detected, particularly from the MDR and PDR subfamilies, which often showed expression in either roots or shoots. Ammonium transporters were expressed in root, but not shoot, tissue. Large numbers of sugar transporters were expressed, particularly in green tissue. The occurrence of phosphorylation sites in rice transporters such as AMT1;1 and PIP2;6 agrees with those previously described in other species, pointing to conserved regulatory mechanisms. New phosphosites were found in many transporters, including H⁺ pumps and H⁺:cation antiporters, often at residues that are well conserved across gene families. Comparison of root and shoot tissue showed that phosphorylation of AMT1;1 and several further transporters may be tissue dependent.