Identification of rate-limiting steps in yeast heme biosynthesis

Hoffman, M. L.; Góra, Monika; Rytka, Joanna

doi:10.1016/j.bbrc.2003.09.151

Cited by 60 publications

(47 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results have also provided a glimpse into how sampangine might inhibit heme biosynthesis. It most likely involves hyperactivation of UIIIS (encoded by HEM4), which is by far the most active enzyme within the heme biosynthesis pathway (14). This model is based on the observations that sampangine stimulates the activity of human UIIIS in vitro and that overexpressing Hem4 inhibits heme synthesis and causes growth defects in yeast cells (Fig.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Sampangine Inhibits Heme Biosynthesis in both Yeast and Human

Huang

Chen

et al. 2011

Eukaryot Cell

View full text Add to dashboard Cite

The azaoxoaporphine alkaloid sampangine exhibits strong antiproliferation activity in various organisms. Previous studies suggested that it somehow affects heme metabolism and stimulates production of reactive oxygen species (ROS). In this study, we show that inhibition of heme biosynthesis is the primary mechanism of action by sampangine and that increases in the levels of reactive oxygen species are secondary to heme deficiency. We directly demonstrate that sampangine inhibits heme synthesis in the yeast Saccharomyces cerevisiae. It also causes accumulation of uroporphyrinogen and its decarboxylated derivatives, intermediate products of the heme biosynthesis pathway. Our results also suggest that sampangine likely works through an unusual mechanism-by hyperactivating uroporhyrinogen III synthase-to inhibit heme biosynthesis. We also show that the inhibitory effect of sampangine on heme synthesis is conserved in human cells. This study also reveals a surprising essential role for the interaction between the mitochondrial ATP synthase and the electron transport chain.

show abstract

Section: Discussionmentioning

confidence: 99%

“…4C) (14). We compared the porphyrin intermediate metabolite profiles of yeast cells grown in the presence and absence of the drug.…”

mentioning

confidence: 99%

Sampangine Inhibits Heme Biosynthesis in both Yeast and Human

Huang

Chen

et al. 2011

Eukaryot Cell

View full text Add to dashboard Cite

show abstract

“…If heme sensitivity happened to be conserved in yeast, this could be a simple tool for the rapid characterization of various mutant forms of At-TSPO. In contrast with plant cells, yeast cells are not sensitive to ALA feeding, probably because of ALA presence and metabolism in the cytosol (Hoffman et al, 2003) and a possible unidirectional transport of this metabolite across the mitochondrial membranes. In yeast, heme biosynthesis is compartmentalized, and the part of heme biosynthetic pathway performed in the cytosol starts with the export of ALA from the mitochondria (Severance and Hamza, 2009).…”

Section: Heterologously Expressed At-tspo Is Downregulated and Sensitmentioning

confidence: 93%

TheArabidopsisMultistress Regulator TSPO Is a Heme Binding Membrane Protein and a Potential Scavenger of Porphyrins via an Autophagy-Dependent Degradation Mechanism

et al. 2011

View full text Add to dashboard Cite

TSPO, a stress-induced, posttranslationally regulated, early secretory pathway-localized plant cell membrane protein, belongs to the TspO/MBR family of regulatory proteins, which can bind porphyrins. This work finds that boosting tetrapyrrole biosynthesis enhanced TSPO degradation in Arabidopsis thaliana and that TSPO could bind heme in vitro and in vivo. This binding required the His residue at position 91 (H91), but not that at position 115 (H115). The H91A and double H91A/H115A substitutions stabilized TSPO and rendered the protein insensitive to heme-regulated degradation, suggesting that heme binding regulates At-TSPO degradation. TSPO degradation was inhibited in the autophagy-defective atg5 mutant and was sensitive to inhibitors of type III phosphoinositide 3-kinases, which regulate autophagy in eukaryotic cells. Mutation of the two Tyr residues in a putative ubiquitin-like ATG8 interacting motif of At-TSPO did not affect heme binding in vitro but stabilized the protein in vivo, suggesting that downregulation of At-TSPO requires an active autophagy pathway, in addition to heme. Abscisic acid-dependent TSPO induction was accompanied by an increase in unbound heme levels, and downregulation of TSPO coincided with the return to steady state levels of unbound heme, suggesting that a physiological consequence of active TSPO downregulation may be heme scavenging. In addition, overexpression of TSPO attenuated aminolevulinic acid-induced porphyria in plant cells. Taken together, these data support a role for TSPO in porphyrin binding and scavenging during stress in plants.

show abstract

“…5B). This indicated that other enzymes in the heme biosynthetic pathway limit protoheme synthesis under normal conditions, in contrast to the rate-limiting role of PBG-D in A. nidulans exposed to RNS (this study) and in normally growing S. cerevisiae (12). Notably, we found more protoheme in A. nidulans exposed to RNS (Fig.…”

Section: Discussionmentioning

confidence: 47%

Heme-Biosynthetic Porphobilinogen Deaminase Protects Aspergillus nidulans from Nitrosative Stress

Zhou

Narukami

Nameki

et al. 2012

Appl Environ Microbiol

View full text Add to dashboard Cite

Microorganisms have developed mechanisms to combat reactive nitrogen species (RNS); however, only a few of the fungal genes involved have been characterized. Here we screened RNS-resistant Aspergillus nidulans strains from fungal transformants obtained by introducing a genomic DNA library constructed in a multicopy vector. We found that the AN0121.3 gene (hemC) encodes a protein similar to the heme biosynthesis enzyme porphobilinogen deaminase (PBG-D) and facilitates RNS-tolerant fungal growth. The overproduction of PBG-D in A. nidulans promoted RNS tolerance, whereas PBG-D repression caused growth that was hypersensitive to RNS. PBG-D levels were comparable to those of cellular protoheme synthesis as well as flavohemoglobin (FHb; encoded by fhbA and fhbB) and nitrite reductase (NiR; encoded by niiA) activities. Both FHb and NiR are hemoproteins that consume nitric oxide and nitrite, respectively, and we found that they are required for maximal growth in the presence of RNS. The transcription of hemC was upregulated by RNS. These results demonstrated that PBG-D is a novel NO-tolerant protein that modulates the reduction of environmental NO and nitrite levels by FHb and NiR. N itric oxide (NO) is the best-characterized of the reactive nitrogen species (RNS), which react to and damage DNA, lipids, and enzymes, as do reactive oxygen species (31, 39). Both enzymatic and chemical reactions can generate NO under physiological conditions. Mammalian NO synthase oxidizes arginine to produce NO, which transduces signals for neuronal communication, inflammation, and smooth-muscle relaxation (24). Macrophages produce NO by inducible NO synthase to fight infective microorganisms and parasites (5). Microorganisms generate NO as an intermediate of denitrification (10). Bacterial nitrification and denitrification processes involve nitrite (NO 2 Ϫ ) as an intermediate, and improper aeration often results in the accumulation of NO 2 Ϫ , which is concentration-dependently dismutated to NO, especially in an acidic environment (43). Thus, NO is ubiquitous in the microbial milieu, and exposure to NO 2 Ϫ and NO should induce microbial mechanisms to survive RNS toxicity.Microorganisms have developed constitutive and inducible strategies for combating RNS. Flavohemoglobin (FHb) is the best known enzyme that is involved in the RNS response, and it is widespread in bacteria, yeast, and filamentous fungi (29). It comprises protoheme-containing hemoglobin-like and flavincontaining ferredoxin-NAD(P)H reductase-like domains that are located in the amino-and carboxy-terminal regions, respectively (16). Flavohemoglobin functions as a nitric oxide dioxygenase (NOD), converts oxygen and NO to less-toxic nitrate, and facilitates NO tolerance (9). Besides FHb, bacteria and fungi produce cytochrome b-and cytochrome P450-type NO reductases (Nor), which reduce NO to nitrous oxide and consequently minimize NO toxicity (34, 42). Another bacterial flavorubredoxin-type Nor is NorVW, which contains a di-iron catalytic center and reduces and detoxifies NO (...

show abstract

Identification of rate-limiting steps in yeast heme biosynthesis

Cited by 60 publications

References 31 publications

Sampangine Inhibits Heme Biosynthesis in both Yeast and Human

Sampangine Inhibits Heme Biosynthesis in both Yeast and Human

TheArabidopsisMultistress Regulator TSPO Is a Heme Binding Membrane Protein and a Potential Scavenger of Porphyrins via an Autophagy-Dependent Degradation Mechanism

Heme-Biosynthetic Porphobilinogen Deaminase Protects Aspergillus nidulans from Nitrosative Stress

Contact Info

Product

Resources

About