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Frontiers in Bioengineering and... 2023Metabolic engineering strategies for terpenoid production have mainly focused on bottlenecks in the supply of precursor molecules and cytotoxicity to terpenoids. In... (Review)
Review
Metabolic engineering strategies for terpenoid production have mainly focused on bottlenecks in the supply of precursor molecules and cytotoxicity to terpenoids. In recent years, the strategies involving compartmentalization in eukaryotic cells has rapidly developed and have provided several advantages in the supply of precursors, cofactors and a suitable physiochemical environment for product storage. In this review, we provide a comprehensive analysis of organelle compartmentalization for terpenoid production, which can guide the rewiring of subcellular metabolism to make full use of precursors, reduce metabolite toxicity, as well as provide suitable storage capacity and environment. Additionally, the strategies that can enhance the efficiency of a relocated pathway by increasing the number and size of organelles, expanding the cell membrane and targeting metabolic pathways in several organelles are also discussed. Finally, the challenges and future perspectives of this approach for the terpenoid biosynthesis are also discussed.
PubMed: 36911190
DOI: 10.3389/fbioe.2023.1132244 -
Journal of Neurochemistry May 2017Most growth factors and hormones are synthesized as pre-pro-proteins which are processed to the biologically active mature protein. The pre- and prodomains are cleaved... (Review)
Review
Most growth factors and hormones are synthesized as pre-pro-proteins which are processed to the biologically active mature protein. The pre- and prodomains are cleaved from the precursor protein in the secretory pathway or, in some cases, extracellularly. The canonical functions of these prodomains are to assist in folding and stabilization of the mature domain, to direct intra and extracellular localization, to facilitate storage, and to regulate bioavailability of their mature counterpart. Recently, exciting evidence has revealed that prodomains of certain growth factors, after cleaved from the precursor pro-protein, can act as independent active signaling molecules. In this review, we discuss the various classical functions of prodomains, and the biological consequences of these pro-peptides acting as ligands. We will focus our attention on the brain-derived neurotrophic factor prodomain (pBDNF), which has been recently described as a novel secreted ligand influencing neuronal morphology and physiology.
Topics: Animals; Brain-Derived Neurotrophic Factor; Hormones; Humans; Intercellular Signaling Peptides and Proteins; Ligands; Protein Precursors
PubMed: 28218971
DOI: 10.1111/jnc.13993 -
Clinical Gastroenterology and... Mar 2024The prevalence of precursor lesions for gastric cancer (GC) and the differential burden between countries of varying GC risk is not well-understood. We conducted a...
BACKGROUND & AIMS
The prevalence of precursor lesions for gastric cancer (GC) and the differential burden between countries of varying GC risk is not well-understood. We conducted a systematic review and meta-analysis to estimate the global prevalence of precursor lesions.
METHODS
We estimated the prevalence of atrophic gastritis (AG), gastric intestinal metaplasia (IM), and dysplasia in regions with low, medium, and high GC incidence. Because IM is an advanced manifestation of AG, we assessed the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. Prevalence was sub-stratified by Helicobacter pylori infection, symptomatology, and period (<2000, 2000-2010, and >2010).
RESULTS
Among the 582 articles that underwent full-text review, 166 studies met inclusion criteria. The global prevalence estimates of AG, IM, and dysplasia were 25.4%, 16.2%, and 2.0%, respectively, on the basis of 126 studies that reported the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. The prevalence of all precursor lesions was higher in high and medium compared with low GC incidence countries (P < .01). Prevalence of AG and IM was significantly higher among H pylori-infected individuals (P < .01) but not statistically different between symptomatic and asymptomatic individuals (P > .17). All precursors demonstrated a secular decrease in prevalence over time.
CONCLUSIONS
Gastric precursor lesions have differences in prevalence in regions with differential GC incidence and are associated with H pylori infection. Because of the substantial prevalence of precursor lesions in both symptomatic and asymptomatic individuals, symptomatic evaluation may not be sufficient to identify individuals at risk. These estimates provide important insights for tailoring GC prevention strategies.
PubMed: 38438000
DOI: 10.1016/j.cgh.2024.02.023 -
Environmental Science & Technology Nov 2022To unravel the complexity of per- and polyfluoroalkyl substances (PFAS) in products and environmental samples, sum parameters that provide relevant information on...
To unravel the complexity of per- and polyfluoroalkyl substances (PFAS) in products and environmental samples, sum parameters that provide relevant information on chemical characteristics are necessary since not all PFAS can be captured by target analysis in case of missing reference standards or if they are not extractable or amenable to the analytical method. Therefore, we evaluated photocatalysis (UV/TiO) as a further total oxidizable precursor approach (PhotoTOP) to characterize perfluoroalkyl acid precursors via their conversion to perfluoroalkyl carboxylic acids (PFCAs). Photocatalysis has the advantage that no salts are needed, allowing direct injection with liquid chromatography-mass spectrometry without time-consuming and potentially discriminating sample cleanup. OH radicals were monitored with OH probes to determine the reactivity. For eight different precursors (diPAPs, FTSAs, FTCAs, -EtFOSAA, PFOSA), mass balance was achieved within 4 h of oxidation, and also, in the presence of matrix, complete conversion was possible. The PhotoTOP was able to predict the precursor chain length of known and here newly identified precursors qualitatively when applied to two PFAS-coated paper samples and technical PFAS mixtures. The length of the perfluorinated carbon chain (n) was mostly conserved in the form of PFCAs (n-1) with only minor fractions of shorter-chain PFCAs. Finally, an unknown fabric sample and a polymer mixture (no PFAS detectable in extracts) were oxidized, and the generated PFCAs indicated the occurrence of side-chain fluorinated polymers.
Topics: Environmental Monitoring; Fluorocarbons; Carboxylic Acids; Water Pollutants, Chemical
PubMed: 36305720
DOI: 10.1021/acs.est.2c05652 -
Seminars in Cell & Developmental Biology Aug 2014Secreted cytokines of the TGFβ family are found in all multicellular organisms and implicated in regulating fundamental cell behaviors such as proliferation,... (Review)
Review
Secreted cytokines of the TGFβ family are found in all multicellular organisms and implicated in regulating fundamental cell behaviors such as proliferation, differentiation, migration and survival. Signal transduction involves complexes of specific type I and II receptor kinases that induce the nuclear translocation of Smad transcription factors to regulate target genes. Ligands of the BMP and Nodal subgroups act at a distance to specify distinct cell fates in a concentration-dependent manner. These signaling gradients are shaped by multiple factors, including proteases of the proprotein convertase (PC) family that hydrolyze one or several peptide bonds between an N-terminal prodomain and the C-terminal domain that forms the mature ligand. This review summarizes information on the proteolytic processing of TGFβ and related precursors, and its spatiotemporal regulation by PCs during development and various diseases, including cancer. Available evidence suggests that the unmasking of receptor binding epitopes of TGFβ is only one (and in some cases a non-essential) function of precursor processing. Future studies should consider the impact of proteolytic maturation on protein localization, trafficking and turnover in cells and in the extracellular space.
Topics: Animals; Humans; Latent TGF-beta Binding Proteins; Models, Molecular; Proprotein Convertases; Protein Binding; Protein Precursors; Protein Structure, Tertiary; Signal Transduction; Transforming Growth Factor beta
PubMed: 24508081
DOI: 10.1016/j.semcdb.2014.01.008 -
Journal of Hepato-biliary-pancreatic... Jul 2023To clarify the pathological significance of two precursors (high-grade biliary intraepithelial neoplasm [BilIN] and intraductal papillary neoplasm of bile duct [IPNB])...
BACKGROUND
To clarify the pathological significance of two precursors (high-grade biliary intraepithelial neoplasm [BilIN] and intraductal papillary neoplasm of bile duct [IPNB]) in cholangiocarcinomas (CCAs).
METHODS
Ninety-one cases of CCA (47 distal CCAs [dCCAs], 31 perihilar CCAs [pCCAs] and 13 intrahepatic CCAs of large duct type [LD-iCCAs]) were examined for their association with precursors. Neoplastic intraepithelial lesions without underlying infiltrating carcinoma in the surrounding mucosa of CCAs were considered to reflect high-grade BilIN. High-grade BilIN and IPNB were subdivided into gastric, biliary, intestinal and oncocytic subtypes, while CCAs were subdivided into gastrobiliary, intestinal and oncocytic subtypes. The postoperative overall survival (OS) was examined.
RESULTS
Fifty-four and 8 of 91 CCAs were associated with high-grade BilIN and IPNB, respectively, while these precursors were unidentifiable in the remaining CCAs. A majority of CCAs were of the gastrobiliary subtype, while the intestinal subtype was occasionally detected, and the oncocytic subtype was rare. CCAs with high-grade BilIN showed a similar postoperative OS to CCAs without precursors, while CCAs with IPNB showed a favorable postoperative OS compared to CCAs without precursors.
CONCLUSIONS
CCAs were frequently associated with precursors; high-grade BilIN may be a major precursor and IPNB a minor one. CCAs with IPNB showed a favorable postoperative OS compared to CCAs with high-grade BilIN.
Topics: Humans; Bile Ducts, Intrahepatic; Bile Duct Neoplasms; Cholangiocarcinoma; Bile Ducts; Carcinoma in Situ; Bile Pigments
PubMed: 36707055
DOI: 10.1002/jhbp.1308 -
The American Journal of Surgical... Aug 2023Recently, the World Health Organization (WHO) recognized the existence of human papillomavirus (HPV)-independent invasive cervical squamous cell carcinoma (SCC), but...
Recently, the World Health Organization (WHO) recognized the existence of human papillomavirus (HPV)-independent invasive cervical squamous cell carcinoma (SCC), but HPV-independent precursor lesions were not included due to the lack of description of this rare entity. We present the histologic spectrum of highly differentiated squamous HPV-negative and p16 ink4a -negative precursor lesions adjacent to and/or preceding invasive HPV-negative cervical SCC in 3 patients. The histologic features resembled those described for vulvar HPV-negative precursor lesions. One precursor featured a proliferation of atypical basal keratinocytes with mitotic activity, premature squamatization in elongated epithelial rete, and mostly regular superficial squamous differentiation with TP53 mutation and immunohistochemical p53 overexpression termed differentiated cervical intraepithelial neoplasia (d-CIN). The other 2 precursors included verruciform acanthosis with plump rete, minimal atypia, and an EGFR mutation that resembled vulvar acanthosis with altered differentiation, and an exophytic papillary proliferation with a PIK3CA mutation resembling the differentiated exophytic vulvar intraepithelial lesion. Two precursors that preceded the invasive SCC harbored an additional pathogenic SMARCB1 mutation. The cytologic smears of d-CIN revealed 3-dimensional branched basaloid tubular structures and eosinophilic squamous cell clusters mimicking the histologic features. In conclusion, highly differentiated cervical HPV-negative precursors are characteristic intraepithelial squamous lesions with somatic mutations that resemble those described in vulvar HPV-independent carcinogenesis. For optimal reproducibility, we propose a simplistic classification of these HPV-negative cervical precursors in TP53 -mutated d-CIN and p53 wild-type verruciform intraepithelial neoplasia.
Topics: Female; Humans; Tumor Suppressor Protein p53; Papillomavirus Infections; Reproducibility of Results; Vulvar Neoplasms; Carcinoma in Situ; Carcinoma, Squamous Cell; Papillomaviridae; Uterine Cervical Dysplasia; Cyclin-Dependent Kinase Inhibitor p16
PubMed: 37283469
DOI: 10.1097/PAS.0000000000002067 -
The New Phytologist Jan 2021The gaseous plant hormone ethylene is produced by a fairly simple two-step biosynthesis route. Despite this pathway's simplicity, recent molecular and genetic studies... (Review)
Review
The gaseous plant hormone ethylene is produced by a fairly simple two-step biosynthesis route. Despite this pathway's simplicity, recent molecular and genetic studies have revealed that the regulation of ethylene biosynthesis is far more complex and occurs at different layers. Ethylene production is intimately linked with the homeostasis of its general precursor S-adenosyl-l-methionine (SAM), which experiences transcriptional and posttranslational control of its synthesising enzymes (SAM synthetase), as well as the metabolic flux through the adjacent Yang cycle. Ethylene biosynthesis continues from SAM by two dedicated enzymes: 1-aminocyclopropane-1-carboxylic (ACC) synthase (ACS) and ACC oxidase (ACO). Although the transcriptional dynamics of ACS and ACO have been well documented, the first transcription factors that control ACS and ACO expression have only recently been discovered. Both ACS and ACO display a type-specific posttranslational regulation that controls protein stability and activity. The nonproteinogenic amino acid ACC also shows a tight level of control through conjugation and translocation. Different players in ACC conjugation and transport have been identified over the years, however their molecular regulation and biological significance is unclear, yet relevant, as ACC can also signal independently of ethylene. In this review, we bring together historical reports and the latest findings on the complex regulation of the ethylene biosynthesis pathway in plants.
Topics: Amino Acid Oxidoreductases; Ethylenes; Gene Expression Regulation, Plant; Lyases; Plants
PubMed: 32790878
DOI: 10.1111/nph.16873 -
Current Protein & Peptide Science 2023With the advent of cancer diagnostics and therapeutics, circular RNAs (circRNAs) are swiftly becoming one of the significant regulators of gene expression and cellular... (Review)
Review
BACKGROUND
With the advent of cancer diagnostics and therapeutics, circular RNAs (circRNAs) are swiftly becoming one of the significant regulators of gene expression and cellular functions. A plethora of multiple molecular mechanisms has been observed to elicit their influence.
OBJECTIVE
Circular RNAs (circRNAs) are a distinct category of endogenous noncoding RNAs designed as a result of exon back splicing events in precursor's mRNAs (pre-mRNAs) and are widely distributed in the transcriptome of eukaryotic cells.
METHODS
Although the role of circRNAs is still in its infancy, they serve as microRNA sponges, protein scaffolds, and modulators of transcription and splicing and occasionally as templates for the production of peptides.
RESULTS
It is well known that abnormal circRNA expression is prevalent in malignancies and has been linked to a number of pathophysiological aspects of cancer. This extensively anomalous expression assists in cellular proliferation and growth, sustaining cellular invasiveness and bypassing cellular senescence and death, thus advocating their promise to serve as both clinical biomarkers and therapeutic targets.
CONCLUSION
An overview of the recent status of circRNA will aid in the identification of new biomarkers, therapeutic targets, and their prospect in the diagnosis and therapy of disease. In this review article, we discuss the functional mechanisms of circRNAs, their biomarker potential in disease diagnosis and prognosis, therapeutic approaches, and the associated limitations.
Topics: Humans; RNA, Circular; Neoplasms; MicroRNAs; Biomarkers; RNA Splicing
PubMed: 36635927
DOI: 10.2174/1389203724666230111113715 -
International Journal of Molecular... Mar 2021Protein post-translational modifications (PTMs) play key roles in eukaryotes since they finely regulate numerous mechanisms used to diversify the protein functions and... (Review)
Review
Protein post-translational modifications (PTMs) play key roles in eukaryotes since they finely regulate numerous mechanisms used to diversify the protein functions and to modulate their signaling networks. Besides, these chemical modifications also take part in the viral hijacking of the host, and also contribute to the cellular response to viral infections. All domains of the human immunodeficiency virus type 1 (HIV-1) Gag precursor of 55-kDa (Pr55), which is the central actor for viral RNA specific recruitment and genome packaging, are post-translationally modified. In this review, we summarize the current knowledge about HIV-1 Pr55 PTMs such as myristoylation, phosphorylation, ubiquitination, sumoylation, methylation, and ISGylation in order to figure out how these modifications affect the precursor functions and viral replication. Indeed, in HIV-1, PTMs regulate the precursor trafficking between cell compartments and its anchoring at the plasma membrane, where viral assembly occurs. Interestingly, PTMs also allow Pr55 to hijack the cell machinery to achieve viral budding as they drive recognition between viral proteins or cellular components such as the ESCRT machinery. Finally, we will describe and compare PTMs of several other retroviral Gag proteins to give a global overview of their role in the retroviral life cycle.
Topics: Cell Membrane; Endosomal Sorting Complexes Required for Transport; HIV-1; Humans; Protein Precursors; Protein Processing, Post-Translational; RNA, Viral; Virus Assembly; Virus Replication; gag Gene Products, Human Immunodeficiency Virus
PubMed: 33799890
DOI: 10.3390/ijms22062871