High impact information on CAT1

• Effects of synergistic signaling by phytochrome A and cryptochrome1 on circadian clock-regulated catalase expression [1].
• Mutational disruption of either phytochrome- or cryptochrome-mediated light perception prevents damping of the oscillations in CAT3 mRNA abundance and reveals strong circadian oscillations that persist for multiple cycles in extended dark conditions [1].
• In Arabidopsis, catalase CAT3 mRNA oscillations damp rapidly in extended dark conditions, but unlike catalase CAT2 and the chlorophyll a/b binding protein gene CAB, in which the circadian oscillations damp to low steady state mRNA abundance, CAT3 mRNA oscillations damp to high steady state levels of mRNA abundance [1].
• Also, the abundance of mRNAs encoding salicylic acid-binding catalase and a pathogenesis-related protein were significantly higher in cells deficient in AOX [2].
• Reduced catalase levels already provoked differences in nuclear gene expression under ambient growth conditions, and these effects were amplified by high light exposure in a sun simulator for 3 and 8 h [3].

Biological context of CAT1

• The amino acid sequences of the three catalase subunits are 75 to 84% identical and 87 to 94% similar, considering conservative substitutions [4].
• Catalase is encoded by a multigene family in Arabidopsis thaliana (L.) Heynh [4].
• CAT1 and CAT3 map to chromosome 1, and CAT2 maps to chromosome 4 [5].
• Regulation of Cat3 gene expression is not dependent on the presence of the Tourist element in the promoter of the gene nor on the presence of motifs similar to those found significant in the circadian expression of the Arabidopsis CAB2 gene [6].
• Structural diversity was revealed in the Cat3 promoters of maize genotypes of diverse origins [6].

Anatomical context of CAT1

• Immunoelectron microscopic analysis using antibodies against the peroxisomal marker protein, catalase, showed the presence of GFP in peroxisomes, confirming that GFP was correctly transported into peroxisomes by PTS1 or PTS2 pathways [7].
• All known microbody enzymes that are synthesized in a form similar in size to the mature molecule, except catalase, contain one of these tripeptide sequences at their carboxyl terminus [8].
• The expression of APX3 in tobacco could protect leaves from oxidative stress damage caused by aminotriazole which inhibits catalase activity that is found mainly in glyoxysomes and peroxisomes and leads to accumulation of H2O2 in those organelles [9].
• Strong expression of the rice catalase gene CatB promoter in protoplasts and roots of both a monocot and dicots [10].
• The rice (Oryza sativa L.) catalase (EC 1.11.1.6) gene CatB is expressed in roots and cultured cells [10].

Associations of CAT1 with chemical compounds

• Intron losses from CAT1 and CAT3 followed these duplications [11].
• The complemented mutant showed higher catalase activity. mRNA expression of the annexin gene in A. thaliana was higher in roots as compared with other organs and was also increased when the plants were exposed to H2O2 stress or salicylic acid [12].
• Application of catalase to NahG or catechol-treated wild-type plants partially restored resistance to Psp, suggesting that the deleterious effect of catechol results from inappropriate production of hydrogen peroxide [13].
• This lsd1 mutant also had reduced stomatal conductance and catalase activity in short-day permissive conditions and induced H(2)O(2) accumulation followed by rcd when stomatal gas exchange was further impeded [14].
• Plants tested were defective in signaling pathways (abscisic acid, salicylic acid, ethylene, and oxidative burst signaling) and in reactive oxygen metabolism (ascorbic acid or glutathione production, catalase) or had previously been found to have temperature-related phenotypes (e.g. fatty acid desaturase mutants, uvh6) [15].

Other interactions of CAT1

• CAT1 then served as the template for a second duplication, yielding CAT2 [11].
• Subtractive hybridization was used to isolate the responsive genes to heterologous CBF1 in transgenic tomato plants and the CAT1 (CATALASE1) was characterized [16].
• Total activities of catalase (CAT, EC 1.11.1.6), peroxidase (POD, EC 1.11.1.7), superoxide dismutase (EC 1.15.1.1) and glutathione reductase (EC 1.6.4.2) increased greatly in response to MeJA, particularly a 100-fold increase in POD activity 7 days after MeJA treatment [17].
• However, it remains unclear whether catalase is imported into peroxisome via the PTS1 system [18].

Analytical, diagnostic and therapeutic context of CAT1

• In addition to an H(2)O(2)-dependent and -independent type of transcriptional response during light stress, microarray analysis on both control and transgenic catalase-deficient plants, exposed to 0, 3, 8, and 23 h of HL, revealed several specific regulatory patterns of gene expression [19].
• Non-denaturing two-dimensional gel electrophoresis of crude extracts from plants revealed that catalase and NDK activities co-migrated in the same area of the gel [20].

References