3.1.3.56 C214S site-directed mutagenesis, mutation in the P-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview -, 751120 3.1.3.56 C409S decreased activity 646397 3.1.3.56 C409S predominantly soluble 646395 3.1.3.56 C939S eliminates isoprenylation of enzyme which reduces activity towards phosphatidylinositol 4,5-bisphosphate 646393 3.1.3.56 D232A no activity 646400 3.1.3.56 D232A traces of activity 646400 3.1.3.56 D384A no activity 646400 3.1.3.56 D771A no activity 646400 3.1.3.56 D838G no activity 646402 3.1.3.56 DELTA1-119 no significant influence on localization of enzyme 646399 3.1.3.56 DELTA1-311 no significant influence on localization of enzyme 646399 3.1.3.56 DELTA1-433 enzyme mainly in cytoplasm 646399 3.1.3.56 DELTA407-411 predominantly soluble 646395 3.1.3.56 DELTA725-1001 enzyme exclusively cytoplasmic 646399 3.1.3.56 E185A site-directed mutagenesis, mutation in the Flex-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview 751120 3.1.3.56 E55A no activity 646400 3.1.3.56 E55Q no activity 646400 3.1.3.56 E597Q site-directed mutagenesis, the mutant enzyme shows an over 140fold increased catalytic efficiency and a 2.4fold reduced affinity for Mg2+ compared to the wild-type enzyme 665575 3.1.3.56 E631A no activity 646400 3.1.3.56 F246A site-directed mutagenesis, mutation in the bulky and hydrophobic loop, inactive mutant 751120 3.1.3.56 F392A 50% of activity 646400 3.1.3.56 H184A traces of activity 646400 3.1.3.56 H219A site-directed mutagenesis, mutation in the P-loop/alpha-helix4, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview -, 751120 3.1.3.56 H385A no activity 646400 3.1.3.56 H730A no activity 646400 3.1.3.56 K184A site-directed mutagenesis, mutation in the Flex-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview 751120 3.1.3.56 K218A site-directed mutagenesis, mutation in the P-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview -, 751120 3.1.3.56 K250A site-directed mutagenesis, mutation in the alpha4-alpha5-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview -, 751120 3.1.3.56 K386A no activity 646400 3.1.3.56 additional information construction of transgenic Arabidopsis thaliana plants expressing the human enzyme, the transgenic plants show no altered growth and life cycle phenotype although the basal level of inositol 1,4,5-trisphosphate is reduced by 90% compared to wild-type plants, but the plants are insensitive to gravitropic stimulation and show no increased InsP3 levels in inflorescence stem under gravistimulation in contrast to wild-type plants, bending responses, overview 666645 3.1.3.56 additional information T-DNA insertional mutants for 5PTase1 (5ptase1-1 and 5ptase1-2, containing a T-DNA insertion within the fifth and fourth introns) and 5PTase2 (5ptase2-1 which contains a T-DNA insertion in the seventh intron) are identified and characterized and a At5PTase1-1/At5PTase2-1 double mutant is produced: grown in dark, seeds from mutants germinate faster than wild-type seeds and the mutant seedlings have longer hypocotyls than wild-type seedlings. Seeds from these mutant lines demonstrate an increase in sensitivity to abscisic acid. These changes in early seedling growth are accompanied by mass increases in Ins(1,4,5)P3, but not by changes in endogenous ABA content. By labeling the endogenous myoinositol pool in 5ptase1 and 5ptase2 mutants, an increases in Ins(1,4,5)P3 and a decrease in PtdIns, PtdIns(4)P, and phosphatidylinositol (4,5)bisphosphate is detected 682411 3.1.3.56 additional information T-DNA insertional mutants for 5PTase1 (5ptase1-1 and 5ptase1-2, containing a T-DNA insertion within the fifth and fourth introns) and 5PTase2 (5ptase2-1 which contains a T-DNA insertion in the seventh intron) are identified and characterized and a At5PTase1-1/At5PTase2-1 double mutant is produced: grown in dark, seeds from mutants germinate faster than wildtype seeds and the mutant seedlings have longer hypocotyls than wild-type seedlings. Seeds from these mutant lines demonstrate an increase in sensitivity to abscisic acid. These changes in early seedling growth are accompanied by mass increases in Ins(1,4,5)P3, but not by changes in endogenous ABA content. By labeling the endogenous myoinositol pool in 5ptase1 and 5ptase2 mutants, an increases in Ins(1,4,5)P3 and a decrease in PtdIns, PtdIns(4)P, and phosphatidylinositol (4,5)bisphosphate is detected 682411 3.1.3.56 N183A site-directed mutagenesis, mutation in the Flex-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview 751120 3.1.3.56 N18A no activity 646400 3.1.3.56 N215A site-directed mutagenesis, mutation in the P-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview 751120 3.1.3.56 P387A traces of activity 646400 3.1.3.56 R216A site-directed mutagenesis, mutation in the P-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview 751120 3.1.3.56 R220A site-directed mutagenesis, mutation in the P-loop/alpha4-helix, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview -, 751120 3.1.3.56 R252A site-directed mutagenesis, mutation in the alpha4-alpha5-loop, the mutant shows altered substrate specificities and activities compared to the wild-type enzyme, overview 751120 3.1.3.56 R343A increased Km and dramatic loss of activity 646396 3.1.3.56 R350A increased Km 646396 3.1.3.56 T16A 100% of activity 646400 3.1.3.56 V388A traces of activity 646400 3.1.3.56 W234A site-directed mutagenesis, mutation in the bulky and hydrophobic loop, the mutant is only active with 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate 751120 3.1.3.56 W281A site-directed mutagenesis, mutation in the bulky and hydrophobic loop, inactive mutant 751120