Receptor-like protein kinase HvLysMR1 of barley (Hordeum vulgare L.) is induced during leaf senescence and heavy metal stress

• Published in: Journal of experimental botany Vol. 58; no. 6; pp. 1381 - 1396
• Main Authors: Ouelhadj, Akli, Kaminski, Marc, Mittag, Maria, Humbeck, Klaus
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-01-2007; Oxford Publishing Limited (England)
• Subjects: Aging; Barley; Biological and medical sciences; Cadmium; Calcimycin - pharmacology; Calcium; Calcium - pharmacology; Cellular senescence; Chlorophyll - metabolism; Chlorophylls; Chromium; Cloning, Molecular; Complementary DNA; DNA, Complementary - genetics; Enzyme Induction - drug effects; Fundamental and applied biological sciences. Psychology; heavy metal stress; Heavy metals; Hordeum - drug effects; Hordeum - enzymology; Hordeum - physiology; Hordeum vulgare; leaf senescence; lysine motif; Messenger RNA; Metals, Heavy - toxicity; Photosystem I Protein Complex - metabolism; Plant Leaves - drug effects; Plant Leaves - enzymology; Plant Leaves - growth & development; Plant physiology and development; Plant Proteins - biosynthesis; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Protein Kinases - biosynthesis; Protein Kinases - genetics; Protein-Serine-Threonine Kinases - biosynthesis; Protein-Serine-Threonine Kinases - genetics; receptor-like kinase; Receptors, Cell Surface - biosynthesis; Receptors, Cell Surface - genetics; Research Papers; Senescence and abscission; Signal Transduction; Vegetative apparatus, growth and morphogenesis. Senescence; heavy metal stress; receptor-like kinase; Calcium; Hordeum vulgare; lysine motif; leaf senescence; Monocotyledones; Senescence; Enzyme; Transferases; Plant leaf; Stress; Heavy metal; Gramineae; Kinase; Protein kinase; Angiospermae; Spermatophyta
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/erl304

The Hordeum vulgare cDNA clone HvLysMR1 that encodes a putative receptor-like protein kinase was identified by restriction fragment differential display-polymerase chain reaction (PCR) comparing cDNA populations derived from mRNAs of primary leaves stressed with chromium for 48 h with controls. The full-length sequence codes for a protein with 622 amino acids which includes characteristic domains of lysine motif receptor-like kinases: an N-terminal signal peptide, two lysine motifs, a transmembrane region, and a serine/threonine kinase domain at the C-terminal end. The expression of HvLysMR1 is induced during exposure to different heavy metals and its transcript accumulates during leaf senescence. Addition of the calcium ionophore A23187 induces HvLysMR1 expression, indicating the involvement of Ca²⁺ in the regulation of HvLysMR1. In vitro phosphorylation of HvLysMR1 was analysed with [³²P]ATP. Using the overexpressed and purified HvLysMR1-kinase domain, the phosphorylation of HvLysMR1 could be confirmed by nano-liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) with neutral loss-triggered MS-MS-MS spectra at amino acids localized at the juxtamembrane region. The involvement of HvLysMR1 during heavy metal stress and leaf senescence is discussed.