scholarly journals Two Deoxythymidine Triphosphate Synthesis-Related Genes Regulate Obligate Symbiont Density and Reproduction in the Whitefly Bemisia tabaci MED

2021 ◽  
Vol 11 ◽  
Author(s):  
Zezhong Yang ◽  
Cheng Gong ◽  
Yuan Hu ◽  
Jie Zhong ◽  
Jixing Xia ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rna Interference ◽  
Bemisia Tabaci ◽  
Essential Amino Acid ◽  
Cellular Growth ◽  
Capacity Analysis ◽  
Host Insect ◽  
Obligate Symbiont ◽  
Pyrimidine Pathway

Deoxythymidine triphosphate (dTTP) is essential for DNA synthesis and cellular growth in all organisms. Here, genetic capacity analysis of the pyrimidine pathway in insects and their symbionts revealed that dTTP is a kind of metabolic input in several host insect/obligate symbiont symbiosis systems, including Bemisia tabaci MED/Candidatus Portiera aleyrodidarum (hereafter Portiera). As such, the roles of dTTP on both sides of the symbiosis system were investigated in B. tabaci MED/Portiera. Dietary RNA interference (RNAi) showed that suppressing dTTP production significantly reduced the density of Portiera, significantly repressed the expression levels of horizontally transferred essential amino acid (EAA) synthesis-related genes, and significantly decreased the reproduction of B. tabaci MED adults as well as the hatchability of their offspring. Our results revealed the regulatory role of dTTP in B. tabaci MED/Portiera and showed that dTTP synthesis-related genes could be potential targets for controlling B. tabaci as well as other sucking pests.

scholarly journals Kynurenine Pathway in Skin Cells: Implications for UV-Induced Skin Damage

2012 ◽  
Vol 5 ◽  
pp. IJTR.S9835 ◽  
Author(s):  
Diba Sheipouri ◽  
Nady Braidy ◽  
Gilles J. Guillemin
Keyword(s):  
Amino Acid ◽  
Essential Amino Acid ◽  
Ultra Violet ◽  
Kynurenine Pathway ◽  
Uv Exposure ◽  
Skin Damage ◽  
Skin Cells ◽  
Amino Acid Tryptophan ◽  
Inflammatory Component

The kynurenine pathway (KP) is the principle route of catabolism of the essential amino acid tryptophan, leading to the production of several neuroactive and immunoregulatory metabolites. Alterations in the KP have been implicated in various neuropsychiatric and neurodegenerative diseases, immunological disorders, and many other diseased states. Although the role of the KP in the skin has been evaluated in small niche fields, limited studies are available regarding the effect of acute ultra violet exposure and the induction of the KP in human skin-derived fibroblasts and keratinocytes. Since UV exposure can illicit an inflammatory component in skin cells, it is highly likely that the KP may be induced in these cells in response to UV exposure. It is also possible that some KP metabolites may act as pro-inflammatory and anti-inflammatory mediators, since the KP is important in immunomodulation.

scholarly journals Role of Glutamine Synthetase in Nitrogen Metabolite Repression in Aspergillus nidulans

2001 ◽  
Vol 183 (20) ◽  
pp. 5826-5833 ◽  
Author(s):  
Soula Margelis ◽  
Cletus D'Souza ◽  
Anna J. Small ◽  
Michael J. Hynes ◽  
Thomas H. Adams ◽  
...  
Keyword(s):  
Amino Acid ◽  
Glutamine Synthetase ◽  
Heterologous Expression ◽  
Aspergillus Nidulans ◽  
Essential Amino Acid ◽  
Gene Encoding ◽  
Nitrogen Metabolite Repression ◽  
Link Type ◽  
Wide Range

ABSTRACT Glutamine synthetase (GS), EC 6.3.1.2 , is a central enzyme in the assimilation of nitrogen and the biosynthesis of glutamine. We have isolated the Aspergillus nidulans glnA gene encoding GS and have shown that glnA encodes a highly expressed but not highly regulated mRNA. Inactivation of glnA results in an absolute glutamine requirement, indicating that GS is responsible for the synthesis of this essential amino acid. Even when supplemented with high levels of glutamine, strains lacking a functionalglnA gene have an inhibited morphology, and a wide range of compounds have been shown to interfere with repair of the glutamine auxotrophy. Heterologous expression of the prokaryotic Anabaena glnA gene from the A. nidulans alcA promoter allowed full complementation of the A. nidulans glnAΔ mutation. However, the A. nidulans fluG gene, which encodes a protein with similarity to prokaryotic GS, did not replace A. nidulans glnA function when similarly expressed. Our studies with theglnAΔ mutant confirm that glutamine, and not GS, is the key effector of nitrogen metabolite repression. Additionally, ammonium and its immediate product glutamate may also act directly to signal nitrogen sufficiency.

Dissecting the pro-tumoural role of the essential amino-acid transporter complex CD98/LAT1

2016 ◽  
Vol 61 ◽  
pp. S73
Author(s):  
Y. Cormerais ◽  
S. Giuliano ◽  
P.A. Massard ◽  
J. Durivault ◽  
E. Hitoshi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Essential Amino Acid ◽  
Amino Acid Transporter ◽  
Acid Transporter

scholarly journals Human hepatic tryptophan 2,3-dioxygenase ubiquitin-dependent protein degradation: The critical role of its exosite as the molecular lynchpin of its substrate-mediated protein stabilization

2019 ◽  
Author(s):  
Sung-Mi Kim ◽  
Yi Liu ◽  
YongQiang Wang ◽  
Shay Karkashon ◽  
Ariel Lewis-Ballester ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Opposite Effect ◽  
Critical Role ◽  
Protein Stabilization ◽  
High Affinity ◽  
Dependent Protein ◽  
Rate Limiting

AbstractHepatic tryptophan 2,3-dioxygenase (TDO) is a cytoplasmic homotetrameric hemoprotein and the rate-limiting enzyme in the irreversible degradation of the essential amino acid L-tryptophan (L-Trp) to N-formylkynurenine, thus controlling the flux of L-Trp into its serotonergic and kynureninic/NAD pathways. TDO has long been recognized to be substrate-inducible via protein stabilization, but the molecular mechanism of this stabilization has remained elusive. Recent elucidation of human TDO (hTDO) crystal structure has identified a high-affinity (Kd ≈ 0.5 μM) Trp-binding exosite in each of its 4 monomeric subunits. Mutation of the Glu105, Trp208 and Arg211 comprising this exosite not only abolished the high-affinity L-Trp binding, but also accelerated the ubiquitin-dependent proteasomal degradation of hTDO. We have further characterized this hTDO degradation by documenting that its ubiquitination by gp78/AMFR and CHIP E2/E3 ligase complexes occurs on external Lys-residues within or vicinal to acidic Asp/Glu and phosphorylated pSer/pThr (DEpSpT)-clusters. Furthermore, we have identified the unstructured hTDO N- and C-termini as imparting relatively high proteolytic instability, as their deletion (ΔNC) markedly prolonged hTDO t1/2. Additionally, although previous studies reported that upon hepatic heme-depletion, the heme-free apoTDO turns over with a t1/2 ≈ 2.2 h relative to the t1/2 of 7.7 h of holoTDO, mutating the axial heme-ligating His328 to Ala has the opposite effect of prolonging hTDO t1/2. Most importantly, introducing the exosite mutation into the ΔNC-deleted or H328A-mutant completely abolished their prolonged half-lives irrespective of L-Trp presence or absence, thereby revealing that the exosite is the molecular lynchpin that defines L-Trp-mediated TDO induction via protein stabilization.

scholarly journals The role of serine, a non-essential amino acid, in the production of cytokines

2019 ◽  
Vol 92 (0) ◽  
pp. 2-P-089
Author(s):  
Hiroya Ohta ◽  
Kento Kurita ◽  
Ibuki Shirakawa ◽  
Jun Okada ◽  
Yuka Ohno ◽  
...  
Keyword(s):  
Amino Acid ◽  
Essential Amino Acid

scholarly journals Indoleamine 2,3-dioxygenase expression is associated with chronic rhinosinusitis with nasal polyps and antrochoanal polyps

2011 ◽  
Vol 49 (3) ◽  
pp. 356-363
Author(s):  
T. Honkanen ◽  
A. Luukkainen ◽  
M. Lehtonen ◽  
T. Paavonen ◽  
J. Karjalainen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chronic Rhinosinusitis ◽  
Essential Amino Acid ◽  
Nasal Polyps ◽  
Allergic Airway Inflammation ◽  
Upper Airways ◽  
Indoleamine 2,3 Dioxygenase ◽  
Amino Acid Tryptophan ◽  
Sinus Mucosa

Chronic rhinosinusitis without and with nasal polyps (CRSwNP and CRSsNP), and antrochoanal polyps are different phenotypes with different pathomechanisms. Indoleamine 2,3-dioxygenase (IDO) is an enzyme expressed in many cells involved in the catabolism of the essential amino acid tryptophan to kynurenine. IDO might have a role in allergic airway inflammation. The aim was to evaluate if IDO expression is associated with CRSsNP, CRSwNP, or ACP. One hundred fifty specimens from the nasal cavity and sinus mucosa were immunohistochemically stained with mAb anti-IDO. The expression of epithelial and leukocyte IDO was associated with CRSwNP and ACP. The presence of ASA intolerance, asthma, atopy, smoking and use of medication did not significantly change the results. The different expression of IDO could putatively indicate the differences in the pathomechanisms of CRSsNP, CRSwNP and ACP. Further studies on the role of IDO in upper airways pathologies are required.

scholarly journals Genetic Disruption of the Multifunctional CD98/LAT1 Complex Demonstrates the Key Role of Essential Amino Acid Transport in the Control of mTORC1 and Tumor Growth

2016 ◽  
Vol 76 (15) ◽  
pp. 4481-4492 ◽  
Author(s):  
Yann Cormerais ◽  
Sandy Giuliano ◽  
Renaud LeFloch ◽  
Benoît Front ◽  
Jerome Durivault ◽  
...  
Keyword(s):  
Amino Acid ◽  
Tumor Growth ◽  
Amino Acid Transport ◽  
Essential Amino Acid ◽  
Acid Transport
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