Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.5.1.61 (porphobilinogen deaminase)
 637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In situ hybridization was used to study the effects of hemin on the expression of the oncogenes c-myc, c-fos, and myb, and on the mRNA level of erythroid porphobilinogen deaminase (PBG-D) and alpha-globin in HEL cells during differentiation. The technique was effective in detecting changes in mRNA levels in small numbers of HEL cells. Hemin stimulation of HEL cells results in an early increase in myb and c-myc expression and a decrease in c-fos mRNA, while increased PBG-D and alpha-globin expression is not seen until 8 h after hemin treatment. Blast-like cells display expression of c-myc, alpha-globin and PBG-D, while the more differentiated cells give a positive response to both c-fos and myb. During HEL cell differentiation, the mechanism of hemin stimulation appears to be through the up regulation of myb and c-myc mRNA and down regulation of c-fos. The subsequent expression of PBG-D and alpha-globin may indicate that early increases in protooncogene expression are first required for the normal progression of erythropoiesis to occur.
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PMID:Early protooncogene expression during hemin-induced differentiation of human erythroleukemic cells. 228 Jun 14

Leaf is an important organ in responding to environmental stresses. To date, chlorophyll metabolism under polycyclic aromatic hydrocarbon (PAH) stress is still unclear. Here we reveal, for the first time, the chlorophyll metabolism of wheat seedling leaves in response to phenanthrene (a model PAH) exposure. In this study, the hydroponic experiment was employed, and the wheat seedlings were exposed to phenanthrene to observe the response at day 1, 3, 5, 7 and 9. Over the exposure time, wheat leaf color turns light. With the accumulation of phenanthrene, the concentrations of glutamate, 5-aminolevulinic acid, uroporphyrinogen III, protoporphyrin IX, Mg-protoporphyrin IX and protochlorophyllide increase while the concentrations of porphobilinogen and Chlorophyll b decrease. Also chlorophyll a content rises initially and then declines. Uroporphyrinogen III synthase and chlorophyllase are activated and porphobilinogen deaminase activity declines in the treatments. Both chlorophyll synthesis and degradation are enhanced, but the degradation rate is faster. Phenanthrene accumulation has significant and positive effects on increase of glutamate, 5-aminolevulinic acid, uroporphyrinogen III, protoporphyrin IX, Mg-protoporphyrin IX and protochlorophyllide concentrations. There is a negative correlation between phenanthrene accumulation and total chlorophyll. Additionally, the leaf moisture increases. Therefore, it is concluded that wheat leaf chlorosis results from a combination of accelerated chlorophyll degradation and elevated leaf moisture under phenanthrene exposure. Our results are helpful not only for better understanding the toxicity of PAHs to plants and crop PAH-adaptive mechanism in the environment, but also for potentially employing the changes of the chlorophyll-synthesizing precursors and enzyme activities in plant leaves as indicators of plant response to PAH pollution.
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PMID:Phenanthrene-triggered Chlorosis is caused by elevated Chlorophyll degradation and leaf moisture. 2783 78

Leaf coloration is one of the most important and attractive characteristics of Ananas comosus var. bracteatus. The chimeric character is not stable during the in vitro tissue culturing. Many regenerated plants lost economic values for the loss of the chimeric character of leaves. In order to reveal the molecular mechanisms involved in the albino phenotype of the leaf cells, the physiological and transcriptional differences between complete white (CWh) and green (CGr) leaf cells of A. comosus var. bracteatus were analyzed. A total of 1,431 differentially expressed unigenes (DEGs) in CGr and CWh leaves were identified using RNA-seq. A comparison to the COG, GO and KEGG annotations revealed DEGs involved in chlorophyll biosynthesis, chloroplast development and photosynthesis. Furthermore, the measurement of main precursors of chlorophyll in the CWh leaves confirmed that the rate-limiting step in chlorophyll biosynthesis, and thus the cause of the albino phenotype of the white cells, was the conversion of pyrrole porphobilinogen (PBG) to uroporphyrinogen III (Uro III). The enzyme activity of porphobilinogen deaminase (PBGD) and uroporporphyrinogn III synthase (UROS), which catalyze the transition of PBG to Uro III, was significantly decreased in the CWh leaves. Our data showed the transcriptional differences between the CWh and CGr plants and characterized key steps in chlorophyll biosynthesis of the CWh leaves. These results contribute to our understanding of the mechanisms and regulation of pigment biosynthesis in the CWh leaf cells of A. comosus var. bracteatus.
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PMID:Physiological Characterization and Comparative Transcriptome Analysis of White and Green Leaves of Ananas comosus var. bracteatus. 2809 62