Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Regulation of arginine metabolism requires the integrity of four regulatory proteins, ArgRI, ArgRII, ArgRIII and Mcm1. To characterize further the interactions between the different proteins, we used the two-hybrid system, which showed that ArgRI and Mcm1 interact together, and with ArgRII and ArgRIII, without an arginine requirement. To define the interacting domains of ArgRI and Mcm1 with ArgRIII, we fused portions of ArgRI and Mcm1 to the DNA-binding domain of Gal4 (GBD) and created mutations in GBD-ArgRI and GBD-Mcm1. The putative alpha helix present in the MADS-box domain of ArgRI and Mcm1 is their major region of interaction with ArgRIII. Interactions between the two MADS-box proteins and ArgRIII were confirmed using affinity chromatography. The requirement for ArgRIII in the control of arginine metabolism can be bypassed in vitro as well as in vivo by overproducing ArgRI or Mcm1, which indicates that ArgRIII is not present in the protein complex formed with the 'arginine boxes'. We show that the impairment of arginine regulation in an argRIII deletant strain is a result of a lack of stability of ArgRI and Mcm1. A mutation in ArgRI, impairing its interaction with ArgRIII, leads to an unstable ArgRI protein in a wild-type strain. ArgRIII integrity is crucial for Mcm1 function, as shown by the marked decreased expression of five genes controlled by Mcm1. However, ArgRIII is likely to recruit other proteins in the yeast cell, as overexpression of Mcm1 does not compensate some physiological defects observed in an argRIII deletant strain.
Mol Microbiol 2000 Jan
PMID:Recruitment of the yeast MADS-box proteins, ArgRI and Mcm1 by the pleiotropic factor ArgRIII is required for their stability. 1063 74

Inositol phosphates (IPs) and their turnover products have been implicated to play important roles in stress signaling in eukaryotic cells. In higher plants genes encoding inositol polyphosphate kinases have been identified previously, but their physiological functions have not been fully resolved. Here we expressed Arabidopsis inositol polyphosphate 6-/3-kinase (AtIpk2beta) in two heterologous systems, i.e. the yeast Saccharomyces cerevisiae and in tobacco (Nicotiana tabacum), and tested the effect on abiotic stress tolerance. Expression of AtIpk2beta rescued the salt-, osmotic- and temperature-sensitive growth defects of a yeast mutant strain (arg82Delta) that lacks inositol polyphosphate multikinase activity encoded by the ARG82/IPK2 gene. Transgenic tobacco plants constitutively expressing AtIpk2beta under the control of the Cauliflower Mosaic Virus 35S promoter were generated and found to exhibit improved tolerance to diverse abiotic stresses when compared to wild type plants. Expression patterns of various stress responsive genes were enhanced, and the activities of anti-oxidative enzymes were elevated in transgenic plants, suggesting a possible involvement of AtIpk2beta in plant stress responses.
Plant Mol Biol 2008 Mar
PMID:Enhancement of stress tolerance in transgenic tobacco plants constitutively expressing AtIpk2beta, an inositol polyphosphate 6-/3-kinase from Arabidopsis thaliana. 1816 21