Higher plant Ca2+-ATPase: primary structure and regulation of mRNA abundance by salt

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 89; no. 19; pp. 9205 - 9209
• Main Authors: Wimmers, L.E. (University of California, Davis, CA), Ewing, N.N, Bennett, A.B
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.10.1992
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Adenosine triphosphatases; ADN; Amino acids; Analytical, structural and metabolic biochemistry; Animals; ARN MENSAJERO; ARN MESSAGER; Biological and medical sciences; CALCIO; CALCIUM; CATION; CATIONES; CLONACION; CLONAGE; CODE GENETIQUE; CODIGO GENETICO; Complementary DNA; DNA; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Genomics; HIBRIDACION; HIDROLASAS; HYBRIDATION; HYDROLASE; Hydrolases; Introns; ION; IONES; LYCOPERSICON ESCULENTUM; Messenger RNA; NUCLEOTIDE; NUCLEOTIDOS; Plants; RNA; SALINIDAD; SALINITE; Ca-ATPase; Enzyme; Ion transport; Primary structure; Gene expression; Salinity; Complementary DNA; Dicotyledones; Angiospermae; Lycopersicon esculentum; Plasma membrane; Spermatophyta; Solanaceae; Molecular cloning; Endoplasmic reticulum; Adaptation
• ISSN: 0027-8424; 1091-6490

Calcium-dependent regulatory mechanisms participate in diverse developmentally, hormonally, and environmentally regulated processes, with the precise control of cytosolic Ca(2+) concentration being critical to such mechanisms. In plant cells, P-type Ca(2+) -ATPases localized in the plasma membrane and the endoplasmic reticulum are thought to play a central role in regulating cytoplasmic Ca(2+) concentrations. Ca(2+)-ATPase activity has been identified in isolated plant cell membranes, but the protein has not been characterized at the molecular level. We have isolated a partial-length cDNA (LCA1) and a complete genomic clone (gLCA13) encoding a putative endoplasmic reticulum-localized Ca(2+)-ATPase in tomato. The deduced amino acid sequence specifies a protein (Lycopersicon Ca(2+)-ATPase) of 1048 amino acids with a molecular mass of 116 kDa, eight probable transmembrane domains, and all of the highly conserved functional domains common to P-type cation-translocating ATPases. In addition, the protein shares approximately 50% amino acid sequence identity with animal sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases but less than 30% identity with other P-type ATPases. Genomic DNA blot hybridization analysis indicates that the Lycopersicon Ca(2+)-ATPase is encoded by a single gene. RNA blot hybridization analysis indicates the presence of three transcript sizes in root tissue and a single, much less abundant, transcript in leaves. Lycopersicon Ca(2+)-ATPase mRNA levels increase dramatically upon a 1-day exposure to 50 mM NaCl. Thus this report describes the primary structure of a higher-plant Ca(2+)-ATPase and the regulation of its mRNA abundance by salt stress