Disease relevance of LOC548210

• This system was used to determine the concentrations of eIF-4C required for the half-maximal rate of translation of satellite tobacco necrosis virus RNA, alfalfa mosaic virus RNA 4, and barley alpha-amylase mRNA [1].
• Application of pertussis toxin to intact aleurone protoplasts inhibited the ability of ABA to activate PLD as well as antagonizing the ability of ABA to down-regulate gibberellic acid-stimulated alpha-amylase production [2].
• CONCLUSION: Members of the rye alpha-amylase inhibitor family are main allergens involved in allergic reactions to cereal flours [3].
• In the presence of polyethylene glycol (PEG), the protoplasts took up exogenously added plasmid DNA containing the reporter gene coding for chloramphenicol acetyl transferase (CAT) linked to a 35S promoter from cauliflower mosaic virus (CaMV) or to barley alpha-amylase gene promoters and expressed CAT activity [4].
• We describe the first reported expression of barley alpha-amylase in E. coli [5].

High impact information on LOC548210

• Using the double-stranded RNA interference technique, we show that HvABI5 and HvVP1 are necessary for the ABA induction of gene expression but have no effect on another hormone-regulated process, the gibberellin-induced and ABA-suppressed expression of alpha-amylase [6].
• Three novel MYB proteins with one DNA binding repeat mediate sugar and hormone regulation of alpha-amylase gene expression [7].
• Although the ABA-induced Ser/Thr protein kinase, PKABA1, is known to suppress GA-induced alpha-amylase expression, PKABA1 RNAi did not hamper the inhibitory effect of ABA on the expression of alpha-amylase, indicating that a PKABA1-independent signaling pathway also may exist [8].
• Transient expression assays also showed that these three OsMYBSs cooperate with a GA-regulated transcription factor, HvMYBGa, in the transactivation of a low-pI barley alpha-amylase gene promoter in the absence of GA [7].
• All alpha-amylase genes isolated from cereals contain a TATCCA element or its variants at positions approximately 90 to 150 bp upstream of the transcription start sites [7].

Chemical compound and disease context of LOC548210

• Isolation, characterization and inhibition by acarbose of the alpha-amylase from Lactobacillus fermentum: comparison with Lb. manihotivorans and Lb. plantarum amylases [9].

Biological context of LOC548210

• Our results indicate that the GAMyb is the sole GA-regulated transcription factor required for transcriptional activation of the high-pI alpha-amylase promoter [10].
• We demonstrated in transient expression experiments that GAMyb activates transcription of a high-pI alpha-amylase promoter fused to a beta-glucuronidase reporter gene in the absence of GA [10].
• We propose that the TAACAAA box is a gibberellin response element, that the TATCCAC box acts cooperatively with the TAACAAA box to give a high level of GA-regulated expression, and that together these motifs form important components of a gibberellin response complex in high-pI alpha-amylase genes [11].
• The promoters of a majority of cereal alpha-amylase genes contain three highly conserved sequences (gibberellin response element, box I, and pyrimidine box) [12].
• Using a barley aleurone transient expression system, we have now localized the site of action of PKABA1 relative to other signal transduction components governing the expression of alpha-amylase [13].

Anatomical context of LOC548210

• C-terminal processing of barley alpha-amylase 1 in malt, aleurone protoplasts, and yeast [14].
• The degradation of alpha-amylase mRNAs correlates with the rapid destruction of endoplasmic reticulum as observed by electron microscopy, a phenomenon that has not been reported previously as a heat shock response [15].
• In the barley (Hordeum vulgare L.) aleurone layer, gibberellic acid (GA(3)) is perceived at the plasma membrane and induces the synthesis and secretion of alpha-amylase [16].
• This result, together with the fact that protoplasts do not have cell walls, suggests that the AGPs that function in alpha-amylase induction reside at the plasma membrane [17].
• Between them, these two oligonucleotides appear to account for all major alpha-amylase mRNAs as judged by hybrid-arrested translation of alpha-amylase mRNAs in a cell-free system [18].

Associations of LOC548210 with chemical compounds

• It has been shown that an ABA-induced protein kinase, PKABA1, mediates the ABA suppression of alpha-amylase expression [13].
• Deletion analysis has previously shown that the major gibberellic acid (GA)- and abscisic acid (ABA)-responsive elements in the promoter of a high-pI alpha-amylase gene of barley are located downstream of -174 (Jacobsen and Close, 1991) [11].
• Cycloheximide blocked alpha-amylase gene expression but failed to block GAmyb gene expression, indicating that protein synthesis is not required for GAmyb gene expression [10].
• However, in the presence of a transcription inhibitor, cordycepin, the resumption of synthesis of alpha-amylase does not take place, indicating that new transcription of alpha-amylase genes is necessary for this recovery process [15].
• The pseudotetrasaccharide acarbose has high affinity for the active site (Ki,app = 1 microM) and low affinity for a secondary site (Kd = 2.3 mM) in barley alpha-amylase 1, distinguished by inhibition kinetics and spectral perturbation [19].

Enzymatic interactions of LOC548210

• Activities of alpha-amylase and alpha-glucosidase were positively and significantly correlated with the seed extracts' abilities to hydrolyze all three starches. beta-Amylase was only significantly correlated with hydrolysis of boiled soluble starch [20].

Other interactions of LOC548210

• A single copy of this region fused to a minimal alpha-amylase promoter (-41) conferred both GA- and ABA-responsive expression on the reporter gene comparable to the positive control, Am(-174)IGN [11].
• RAST inhibition showed minimal crossreactivity between barley alpha or beta-amylase and barley and fungal alpha-amylase [21].

Analytical, diagnostic and therapeutic context of LOC548210

• A total of 15 variants were compared with the wild type by monitoring the alpha-amylase and protease inhibitory activities using Blue Starch and azoalbumin, respectively, and the kinetics of binding to target enzymes by surface plasmon resonance [22].
• We compared steady-state mRNA levels from these individual genes to levels for mRNAs from two low pI alpha-amylase genes and from the single copy gene for aleurain, a thiol protease, using quantitative S1 nuclease protection assays [23].
• Crystallization of barley malt alpha-amylases and preliminary x-ray diffraction studies of the high pI isozyme, alpha-amylase 2 [24].
• Isolation and sequence analysis of a barley alpha-amylase cDNA clone [25].
• Site-directed mutagenesis of histidine 93, aspartic acid 180, glutamic acid 205, histidine 290, and aspartic acid 291 at the active site and tryptophan 279 at the raw starch binding site in barley alpha-amylase 1 [19].

References