Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ca2+-dependent protein kinase (CDPK-1) was purified from maize seedlings, and its substrate specificity studied using a set of synthetic peptides derived from the phosphorylatable sequence RVLSRLHS15VRER of maize sucrose synthase 2. The decapeptide LARLHSVRER was found to be efficiently phosphorylated as a minimal substrate. The same set of peptides were found to be phosphorylated by mammalian protein kinase Cbeta (PKC), but showed low reactivity with protein kinase A (PKA). Proceeding from the sequence LARLHSVRER, a series of cellulose-membrane-attached peptides of systematically modified structure was synthesised. These peptides had hydrophobic (Ala, Leu) and ionic (Arg, Glu) amino acids substituted in each position. The phosphorylation of these substrates by CDPK-1 was measured and the substrate specificity of the maize protein kinase characterised by the consensus sequence motif A/L-5X-4R-3X-2X-1SX+1R+2Z+3R+4, where X denotes a position with no strict amino acid requirements and Z a position strictly not tolerating arginine compared with the other three varied amino acids. This motif had a characteristic sequence element RZR at positions +2 to +4 and closely resembled the primary structure of the sucrose synthase phosphorylation site. The sequence surrounding the phosphorylatable serine in this consensus motif was similar to the analogous sequence K/RXXS/TXK/R proposed for mammalian PKC, but different from the consensus motif RRXS/TX for PKA.
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PMID:Peptide phosphorylation by calcium-dependent protein kinase from maize seedlings. 1063 3

The regulation of sugar metabolism and partitioning plays an essential role for a plant's acclimation to its environment, with specific responses in autotrophic and heterotrophic organs. In this work, we analyzed the effects of high salinity on sugar partitioning and vascular anatomy within the floral stem. Stem sucrose and fructose content increased, while starch reduced, in contrast to the response observed in rosette leaves of the same plants. In the stem, the effects were associated with changes in the expression of SWEET and TMT2 genes encoding sugar transporters, SUSY1 encoding a sucrose synthase and several FRK encoding fructokinases. By contrast, the expression of SUC2, SWEET11 and SWEET12, encoding sugar transporters for phloem loading, remained unchanged in the stem. Both the anatomy of vascular tissues and the composition of xylem secondary cell walls were altered, suggesting that high salinity triggered major readjustments of sugar partitioning in this heterotrophic organ. There were changes in the composition of xylem cell walls, associated with the collapse and deformation of xylem vessels. The data are discussed regarding sugar partitioning and homeostasis of sugars in the vascular tissues of the stem.
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PMID:Salinity Effects on Sugar Homeostasis and Vascular Anatomy in the Stem of the Arabidopsis Thaliana Inflorescence. 3126 14