@Article{IPB-1749, author = {Guranowski, A. and Miersch, O. and Staswick, P. E. and Suza, W. and Wasternack, C. and}, title = {{Substrate specificity and products of side-reactions catalyzed by jasmonate:amino acid synthetase (JAR1)}}, year = {2007}, pages = {815-820}, journal = {FEBS Lett.}, doi = {10.1016/j.febslet.2007.01.049}, volume = {581}, abstract = {Jasmonate:amino acid synthetase (JAR1) is involved in the function of jasmonic acid (JA) as a plant hormone. It catalyzes the synthesis of several JA‐amido conjugates, the most important of which appears to be JA‐Ile. Structurally, JAR1 is a member of the firefly luciferase superfamily that comprises enzymes that adenylate various organic acids. This study analyzed the substrate specificity of recombinant JAR1 and determined whether it catalyzes the synthesis of mono‐ and dinucleoside polyphosphates, which are side‐reaction products of many enzymes forming acyl ∼ adenylates. Among different oxylipins tested as mixed stereoisomers for substrate activity with JAR1, the highest rate of conversion to Ile‐conjugates was observed for (±)‐JA and 9,10‐dihydro‐JA, while the rate of conjugation with 12‐hydroxy‐JA and OPC‐4 (3‐oxo‐2‐(2Z ‐pentenyl)cyclopentane‐1‐butyric acid) was only about 1–2% that for (±)‐JA. Of the two stereoisomers of JA, (−)‐JA and (\+)‐JA, rate of synthesis of the former was about 100‐fold faster than for (\+)‐JA. Finally, we have demonstrated that (1) in the presence of ATP, Mg2\+, (−)‐JA and tripolyphosphate the ligase produces adenosine 5′‐tetraphosphate (p4A); (2) addition of isoleucine to that mixture halts the p4A synthesis; (3) the enzyme produces neither diadenosine triphosphate (Ap3A) nor diadenosine tetraphosphate (Ap4A) and (4) Ap4A cannot substitute ATP as a source of adenylate in the complete reaction that yields JA‐Ile.} } @Article{IPB-1968, author = {Bücking, H. and Förster, H. and Stenzel, I. and Miersch, O. and Hause, B. and}, title = {{Applied jasmonates accumulate extracellularly in tomato, but intracellularly in barley}}, year = {2004}, pages = {45-50}, journal = {FEBS Lett.}, doi = {10.1016/S0014-5793(04)00178-4}, volume = {562}, abstract = {Jasmonic acid (JA) and its derivatives are well‐characterized signaling molecules in plant defense and development, but the site of their localization within plant tissue is entirely unknown. To address the question whether applied JA accumulates extracellularly or intracellularly, leaves of tomato and barley were fed with 14C‐labeled JA and the label was localized in cryofixed and lyophilized leaf tissues by microautoradiography. In tomato the radioactivity was detectable within the apoplast, but no label was found within the mesophyll cells. By contrast, in barley leaf tissues, radioactivity was detected within the mesophyll cells suggesting a cellular uptake of exogenously applied JA. JA, applied to leaves of both plants as in the labeling experiments, led in all leaf cells to the expression of JA‐inducible genes indicating that the perception is completed by JA signal transduction.} } @Article{IPB-2304, author = {Churin, J. and Hause, B. and Feussner, I. and Maucher, H. P. and Feussner, K. and Börner, T. and Wasternack, C. and}, title = {{Cloning and expression of a new cDNA from monocotyledonous plants coding for a diadenosine 5′,5′′′-P1,P4-tetraphosphate hydrolase from barley (Hordeum vulgare)}}, year = {1998}, pages = {481-485}, journal = {FEBS Lett.}, doi = {10.1016/S0014-5793(98)00819-9}, volume = {431}, abstract = {From a cDNA library generated from mRNA of white leaf tissues of the ribosome‐deficient mutant ‘albostrians\' of barley (Hordeum vulgare cv. Haisa) a cDNA was isolated carrying 54.2% identity to a recently published cDNA which codes for the diadenosine‐5′,5′′′‐P1,P4‐tetraphosphate (Ap4A) hydrolase of Lupinus angustifolius (Maksel et al. (1998) Biochem. J. 329, 313–319), and 69% identity to four partial peptide sequences of Ap4A hydrolase of tomato. Overexpression in Escherichia coli revealed a protein of about 19 kDa, which exhibited Ap4A hydrolase activity and cross‐reactivity with an antibody raised against a purified tomato Ap4A hydrolase (Feussner et al. (1996) Z. Naturforsch. 51c, 477–486). Expression studies showed an mRNA accumulation in all organs of a barley seedling. Possible functions of Ap4A hydrolase in plants will be discussed.} } @Article{IPB-2301, author = {Bohlmann, H. and Vignutelli, A. and Hilpert, B. and Miersch, O. and Wasternack, C. and Apel, K. and}, title = {{Wounding and chemicals induce expression of the Arabidopsis thaliana gene Thi2.1, encoding a fungal defense thionin, via the octadecanoid pathway}}, year = {1998}, pages = {281-286}, journal = {FEBS Lett.}, doi = {10.1016/S0014-5793(98)01251-4}, volume = {437}, abstract = {In seedlings of Arabidopsis thaliana the thionin gene Thi2.1 is inducible by methyl jasmonate, wounding, silver nitrate, coronatine, and sorbitol. We have used a biochemical and genetic approach to test the signal transduction of these different inducers. Both exogenously applied jasmonates and jasmonates produced endogenously upon stress induction, lead to GUS expression in a Thi2.1 promoter-uidA transgenic line. No GUS expression was observed in a coi1 mutant background which lacks jasmonate perception whereas methyl jasmonate and coronatine but not the other inducers were able to overcome the block in jasmonic acid production in a fad3-2 fad7-2 fad8 mutant background. Our results show conclusively that all these inducers regulate Thi2-1 gene expression via the octadecanoid pathway.} } @Article{IPB-2345, author = {Feussner, K. and Feussner, I. and Leopold, I. and Wasternack, C. and}, title = {{Isolation of a cDNA coding for an ubiquitin-conjugating enzyme UBC1 of tomato - the first stress-induced UBC of higher plants}}, year = {1997}, pages = {211-215}, journal = {FEBS Lett.}, doi = {10.1016/S0014-5793(97)00509-7}, volume = {409}, abstract = {A clone of an ubiquitin‐conjugating enzyme (UBC) was isolated from a λ‐ZAP‐cDNA library, generated from mRNA of tomato (Lycopersicon esculentum) cells grown in suspension for 3 days. The open reading frame called Le UBC1, encodes for a polypeptide with a predicted molecular mass of 21.37 kDa, which was confirmed by bacterial overexpression and SDS‐PAGE. Database searches with Le UBC1 showed highest sequence similarities to UBC1 of bovine and yeast. By Southern blot analysis Le UBC1 was identified as a member of a small E2 subfamily of tomato, presumably consisting of at least two members. As revealed by Northern blot analysis Le UBC1 is constitutively expressed in an exponentially growing tomato cell culture. In response to heat shock an increase in Le UBC1‐mRNA was detectable. A strong accumulation of the Le UBC1‐transcript was observed by exposure to heavy metal stress which was performed by treatment with cadmium chloride (CdCl2). The cellular uptake of cadmium was controlled via ICP‐MS measurements. The data suggest that like in yeast, in plants a certain subfamily of UBC is specifically involved in the proteolytic degradation of abnormal proteins as result of stress.} } @Article{IPB-2359, author = {Kramell, R. and Miersch, O. and Hause, B. and Ortel, B. and Parthier, B. and Wasternack, C. and}, title = {{Amino acid conjugates of jasmonic acid induce jasmonate-responsive gene expression in barley (Hordeum vulgare L.) leaves}}, year = {1997}, pages = {197-202}, journal = {FEBS Lett.}, doi = {10.1016/S0014-5793(97)01005-3}, volume = {414}, abstract = {Leaves of barley (Hordeum vulgare L. cv. Salome ) treated with jasmonic acid (JA), its methyl ester (JM), or its amino acid conjugates exhibit up‐regulation of specific genes and down‐regulation of house‐keeping genes. This transcriptional regulation exhibits several specificities. (i) The (−)‐enantiomers are more active, and conjugates are mainly active if they carry an l ‐amino acid moiety. (ii) The various JA‐responsive genes respond differentially to enantiomeric and chiralic forms. (iii) Both JA and its amino acid conjugates exhibiting no or negligible interconversion induce/repress genes.} } @Article{IPB-2355, author = {Hertel, S. C. and Knöfel, H.-D. and Kramell, R. and Miersch, O. and}, title = {{Partial purification and characterization of a jasmonic acid conjugate cleaving amidohydrolase from the fungus Botryodiplodia theobromae}}, year = {1997}, pages = {105-110}, journal = {FEBS Lett.}, doi = {10.1016/S0014-5793(97)00307-4}, volume = {407}, abstract = {A protein preparation from the mycelium of the tropical pathogenic fungus Botryodiplodia theobromae revealed a novel peptidase activity. This enzyme was capable of cleaving conjugates of jasmonic acid with α-amino acids. The protein was enriched 108-fold by gel filtration, ion exchange and hydrophobic interaction chromatography. The enzyme was found to be a glycoprotein with a molecular mass of about 107 kDa. The amidohydrolase seems to be very specific with regard to (−)-jasmonic acid and α-amino acids with (S)-configuration.} }