scholarly journals Role of the hemA gene product and delta-aminolevulinic acid in regulation of Escherichia coli heme synthesis.

1997 ◽  
Vol 179 (14) ◽  
pp. 4583-4590 ◽  
Author(s):  
E Verderber ◽  
L J Lucast ◽  
J A Van Dehy ◽  
P Cozart ◽  
J B Etter ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Aminolevulinic Acid ◽  
Heme Synthesis ◽  
Hema Gene

scholarly journals Interplay between the Specific Chaperone-Like Proteins HybG and HypC in Maturation of Hydrogenases 1, 2, and 3 from Escherichia coli

2001 ◽  
Vol 183 (9) ◽  
pp. 2817-2822 ◽  
Author(s):  
Melanie Blokesch ◽  
Axel Magalon ◽  
August Böck
Keyword(s):  
Escherichia Coli ◽  
Complex Formation ◽  
Gene Product ◽  
Genetic Background ◽  
Large Subunit ◽  
Cysteine Residue ◽  
Maturation Process ◽  
Hydrogenase 3 ◽  
Hydrogenase 2

ABSTRACT The hybG gene product from Escherichia colihas been identified as a chaperone-like protein acting in the maturation of hydrogenases 1 and 2. It was shown that HybG forms a complex with the precursor of the large subunit of hydrogenase 2. As with HypC, which is the chaperone-like protein involved in hydrogenase 3 maturation, the N-terminal cysteine residue is crucial for complex formation. Introduction of a deletion into hybG abolished the generation of active hydrogenase 2 but only quantitatively reduced hydrogenase 1 activity since HypC could replace HybG in this function. In contrast, HybG could not take over the role of HypC in a ΔhypC genetic background. Overproduction of HybG, especially of the variants with the replaced N-terminal cysteine residue, strongly interfered with hydrogenase 3 maturation, apparently by titrating some other component(s) of the maturation machinery. The results indicate that the three hydrogenase isoenzymes not only are interacting at the functional level but are also interconnected during the maturation process.

scholarly journals The role of the regulator-gene product (repressor) in catabolite repression of β-galactosidase synthesis in Escherichia coli

1968 ◽  
Vol 106 (2) ◽  
pp. 339-343 ◽  
Author(s):  
J. Palmer ◽  
V. Moses
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Catabolite Repression ◽  
Lac Repressor ◽  
Temperature Sensitive ◽  
Sensitive Mutant ◽  
Amber Suppressor ◽  
Transient Repression ◽  
I Gene

1. The specific role of the lac repressor (i-gene product) in transient catabolite repression evoked by the introduction of glucose into the medium has been investigated in Escherichia coli by using mutants of the i-gene. 2. A temperature-sensitive mutant (iTL) is normally inducible and demonstrates transient repression when grown at 32°. At 42° it is about 20% constitutive and transient catabolite repression is abolished. 3. A strain carrying an amber suppressor-sensitive mutation in the i-gene is phenotypically constitutive and also fails to show transient catabolite repression. 4. Insertion of Flaci+ into this strain restores both inducibility and transient repression. 5. It is concluded that the i-gene product interacts with the catabolite co-repressor in such a way that its affinity for the operator is increased.

scholarly journals New Insights into the Pivotal Role of Iron/Heme Metabolism in TLR4/NF-κB Signaling-Mediated Inflammatory Responses in Human Monocytes

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2549
Author(s):  
Dong Young Kang ◽  
Nipin Sp ◽  
Eun Seong Jo ◽  
Jin-Moo Lee ◽  
Kyoung-Jin Jang
Keyword(s):  
Iron Metabolism ◽  
High Glucose ◽  
Aminolevulinic Acid ◽  
Inflammatory Responses ◽  
Heme Biosynthesis ◽  
Heme Synthesis ◽  
Heme Metabolism ◽  
Inflammatory Conditions ◽  
Iron Heme

Iron metabolism and heme biosynthesis are essential processes in cells during the energy cycle. Alteration in these processes could create an inflammatory condition, which results in tumorigenesis. Studies are conducted on the exact role of iron/heme metabolism in induced inflammatory conditions. This study used lipopolysaccharide (LPS)- or high-glucose-induced inflammation conditions in THP-1 cells to study how iron/heme metabolism participates in inflammatory responses. Here, we used iron and heme assays for measuring total iron and heme. We also used flow cytometry and Western blotting to analyze molecular responses. Our results demonstrated that adding LPS or high-glucose induced iron formation and heme synthesis and elevated the expression levels of proteins responsible for iron metabolism and heme synthesis. We then found that further addition of heme or 5-aminolevulinic acid (ALA) increased heme biosynthesis and promoted inflammatory responses by upregulating TLR4/NF-κB and inflammatory cytokine expressions. We also demonstrated the inhibition of heme synthesis using succinylacetone (SA). Moreover, N-MMP inhibited LPS- or high-glucose-induced inflammatory responses by inhibiting TLR4/NF-κB signaling. Hence, iron/heme metabolism checkpoints could be considered a target for treating inflammatory conditions.

Sign in / Sign up

Export Citation Format

Share Document