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International Journal of Molecular... Dec 2021Cardiovascular complications due to accelerated arterial stiffening and atherosclerosis are the leading cause of morbimortality in Western society. Both pathologies are... (Review)
Review
Cardiovascular complications due to accelerated arterial stiffening and atherosclerosis are the leading cause of morbimortality in Western society. Both pathologies are frequently associated with vascular calcification. Pathologic calcification of cardiovascular structures, or vascular calcification, is associated with several diseases (for example, genetic diseases, diabetes, and chronic kidney disease) and is a common consequence of aging. Calcium phosphate deposition, mainly in the form of hydroxyapatite, is the hallmark of vascular calcification and can occur in the medial layer of arteries (medial calcification), in the atheroma plaque (intimal calcification), and cardiac valves (heart valve calcification). Although various mechanisms have been proposed for the pathogenesis of vascular calcification, our understanding of the pathogenesis of calcification is far from complete. However, in recent years, some risk factors have been identified, including high serum phosphorus concentration (hyperphosphatemia) and defective synthesis of pyrophosphate (pyrophosphate deficiency). The balance between phosphate and pyrophosphate, strictly controlled by several genes, plays a key role in vascular calcification. This review summarizes the current knowledge concerning phosphate and pyrophosphate homeostasis, focusing on the role of extracellular pyrophosphate metabolism in aortic smooth muscle cells and macrophages.
Topics: Diphosphates; Humans; Phosphates; Vascular Calcification
PubMed: 34948333
DOI: 10.3390/ijms222413536 -
Nature Jun 2022All known triterpenes are generated by triterpene synthases (TrTSs) from squalene or oxidosqualene. This approach is fundamentally different from the biosynthesis of...
All known triterpenes are generated by triterpene synthases (TrTSs) from squalene or oxidosqualene. This approach is fundamentally different from the biosynthesis of short-chain (C-C) terpenes that are formed from polyisoprenyl diphosphates. In this study, two fungal chimeric class I TrTSs, Talaromyces verruculosus talaropentaene synthase (TvTS) and Macrophomina phaseolina macrophomene synthase (MpMS), were characterized. Both enzymes use dimethylallyl diphosphate and isopentenyl diphosphate or hexaprenyl diphosphate as substrates, representing the first examples, to our knowledge, of non-squalene-dependent triterpene biosynthesis. The cyclization mechanisms of TvTS and MpMS and the absolute configurations of their products were investigated in isotopic labelling experiments. Structural analyses of the terpene cyclase domain of TvTS and full-length MpMS provide detailed insights into their catalytic mechanisms. An AlphaFold2-based screening platform was developed to mine a third TrTS, Colletotrichum gloeosporioides colleterpenol synthase (CgCS). Our findings identify a new enzymatic mechanism for the biosynthesis of triterpenes and enhance understanding of terpene biosynthesis in nature.
Topics: Ascomycota; Colletotrichum; Cyclization; Diphosphates; Squalene; Substrate Specificity; Talaromyces; Triterpenes
PubMed: 35650436
DOI: 10.1038/s41586-022-04773-3 -
Current Opinion in Rheumatology Nov 2022The aim of this study was to provide updated information on the prevalence, pathogenesis, diagnostics and therapeutics of calcinosis cutis associated with systemic... (Review)
Review
PURPOSE OF REVIEW
The aim of this study was to provide updated information on the prevalence, pathogenesis, diagnostics and therapeutics of calcinosis cutis associated with systemic sclerosis (SSc).
RECENT FINDINGS
Observational studies show ethnic and geographical differences in the prevalence of calcinosis. In addition to clinical and serological associations, biochemical studies and in-vivo models have attempted to explain theories behind its pathogenesis, including prolonged state of inflammation, mechanical stress, hypoxia and dysregulation in bone and phosphate metabolism. Long-term use of proton pump inhibitors may increase the risk for calcinosis in SSc. Few single-centre observational studies have shown mild benefit with minocycline and topical sodium thiosulfate.
SUMMARY
Calcinosis cutis is the deposition of insoluble calcium in the skin and subcutaneous tissues. It affects up to 40% of SSc patients and causes significant morbidity. Long disease duration, features of vascular dysfunction and osteoporosis have been associated with calcinosis. Altered levels of inorganic pyrophosphate and fibroblast growth factor-23 have been implicated in dysregulated phosphate metabolism that may lead to calcinosis in SSc. Plain radiography can help with diagnosis and quantifying the calcinosis burden. Surgical treatment remains the most effective therapy when feasible. At present, no medical therapies have proven efficacy in large randomized controlled trials.
Topics: Calcinosis; Calcium; Diphosphates; Humans; Minocycline; Proton Pump Inhibitors; Scleroderma, Systemic
PubMed: 35993867
DOI: 10.1097/BOR.0000000000000896 -
Current Opinion in Chemical Biology Oct 2022Inositol pyrophosphates (PP-InsPs) constitute a group of highly charged messengers, which regulate central biological processes in health and disease, such as cellular... (Review)
Review
Inositol pyrophosphates (PP-InsPs) constitute a group of highly charged messengers, which regulate central biological processes in health and disease, such as cellular phosphate and general energy homeostasis. Deciphering the molecular mechanisms underlying PP-InsP-mediated signaling remains a challenge due to the unique properties of these molecules, the different modes of action they can access, and a somewhat limited chemical and analytical toolset. Herein, we summarize the most recent mechanistic insights into PP-InsP signaling, which illustrate our progress in connecting mechanism and function of PP-InsPs.
Topics: Biological Phenomena; Diphosphates; Inositol Phosphates; Phosphates; Signal Transduction
PubMed: 35780751
DOI: 10.1016/j.cbpa.2022.102177 -
Aging Dec 2018
Topics: Calcinosis; Diphosphates; Humans; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Phosphates
PubMed: 30530922
DOI: 10.18632/aging.101703 -
Cellular Microbiology Jun 2021Inositol polyphosphates (IPs) and inositol pyrophosphates (PP-IPs) regulate diverse cellular processes in eukaryotic cells. IPs and PP-IPs are highly negatively charged... (Review)
Review
Inositol polyphosphates (IPs) and inositol pyrophosphates (PP-IPs) regulate diverse cellular processes in eukaryotic cells. IPs and PP-IPs are highly negatively charged and exert their biological effects by interacting with specific protein targets. Studies performed predominantly in mammalian cells and model yeasts have shown that IPs and PP-IPs modulate target function through allosteric regulation, by promoting intra- and intermolecular stabilization and, in the case of PP-IPs, by donating a phosphate from their pyrophosphate (PP) group to the target protein. Technological advances in genetics have extended studies of IP function to microbial pathogens and demonstrated that disrupting PP-IP biosynthesis and PP-IP-protein interaction has a profound impact on pathogenicity. This review summarises the complexity of IP-mediated regulation in eukaryotes, including microbial pathogens. It also highlights examples of poor conservation of IP-protein interaction outcome despite the presence of conserved IP-binding domains in eukaryotic proteomes.
Topics: Bacteria; Diphosphates; Eukaryotic Cells; Humans; Inositol; Polyphosphates; Protein Interaction Maps; Proteome; Virulence
PubMed: 33721399
DOI: 10.1111/cmi.13325 -
Biochemical Society Transactions Feb 2016To help define the molecular basis of cellular signalling cascades, and their biological functions, there is considerable value in utilizing a high-quality chemical... (Review)
Review
To help define the molecular basis of cellular signalling cascades, and their biological functions, there is considerable value in utilizing a high-quality chemical 'probe' that has a well-defined interaction with a specific cellular protein. Such reagents include inhibitors of protein kinases and small molecule kinases, as well as mimics or antagonists of intracellular signals. The purpose of this review is to consider recent progress and promising future directions for the development of novel molecules that can interrogate and manipulate the cellular actions of inositol pyrophosphates (PP-IPs)--a specialized, 'energetic' group of cell-signalling molecules in which multiple phosphate and diphosphate groups are crammed around a cyclohexane polyol scaffold.
Topics: Animals; Diphosphates; Humans; Inositol Phosphates; Phosphotransferases (Phosphate Group Acceptor); Protein Kinase Inhibitors; Signal Transduction
PubMed: 26862205
DOI: 10.1042/BST20150184 -
Chembiochem : a European Journal of... Jun 2019Nonribosomal peptides are a prolific source of bioactive molecules biosynthesized on large, modular assembly line synthetases. Synthetic biologists seek to obtain... (Review)
Review
Nonribosomal peptides are a prolific source of bioactive molecules biosynthesized on large, modular assembly line synthetases. Synthetic biologists seek to obtain tailored peptides with tuned or novel bioactivities by engineering modules and domains of these nonribosomal peptide synthetases. The activation step catalyzed by adenylation domains primarily selects which amino acids are incorporated into nonribosomal peptides. Here, we review experimental protocols for probing the adenylation reaction that are applicable in natural product discovery and engineering. Several alternatives to the established pyrophosphate exchange assay will be compared and potential pitfalls pointed out. Binding pocket mutagenesis of adenylation domains has been successfully conducted to adjust substrate preferences. Novel screening methods relying on yeast surface display, for instance, search a larger sequence space for improved mutants and thus allow more substantial changes in peptide structure.
Topics: Bioengineering; Cell Surface Display Techniques; Diphosphates; Kinetics; Peptide Biosynthesis, Nucleic Acid-Independent; Peptide Synthases; Peptides; Protein Domains; Substrate Specificity
PubMed: 30629787
DOI: 10.1002/cbic.201800750 -
Movement Disorders Clinical Practice Jan 2024Variants in dehydrodolichol diphosphate synthetase (DHDDS) and nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) cause a neurodevelopmental disorder, classically with... (Review)
Review
BACKGROUND
Variants in dehydrodolichol diphosphate synthetase (DHDDS) and nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) cause a neurodevelopmental disorder, classically with prominent epilepsy. Recent reports suggest a complex movement disorder and an overlapping phenotype has been postulated due to their combined role in dolichol synthesis.
CASES
We describe three patients with heterozygous variants in DHDDS and five with variants affecting NUS1. They bear a remarkably similar phenotype of a movement disorder dominated by multifocal myoclonus. Diagnostic clues include myoclonus exacerbated by action and facial involvement, and slowly progressive or stable, gait ataxia with disproportionately impaired tandem gait. Myoclonus is confirmed with neurophysiology, including EMG of facial muscles.
LITERATURE REVIEW
Ninety-eight reports of heterozygous variants in DHDDS, NUS1 and chromosome 6q22.1 structural alterations spanning NUS1, confirm the convergent phenotype of hypotonia at birth, developmental delay, multifocal myoclonus, ataxia, dystonia and later parkinsonism with or without generalized epilepsy. Other features include periodic exacerbations, stereotypies, anxiety, and dysmorphisms. Although their gene products contribute to dolichol biosynthesis, a key step in N-glycosylation, transferrin isoform profiles are typically normal. Imaging is normal or non-specific.
CONCLUSIONS
Recognition of their shared phenotype may expedite diagnosis through chromosomal microarray and by including DHDDS/NUS1 in movement disorder gene panels.
Topics: Infant, Newborn; Humans; Diphosphates; Myoclonus; Movement Disorders; Phenotype; Ataxia; Dolichols; Receptors, Cell Surface
PubMed: 38291835
DOI: 10.1002/mdc3.13920 -
Current Opinion in Structural Biology Oct 2022Enzymes that use thiamin diphosphate (ThDP), the biologically active derivative of vitamin B1, as a cofactor play important roles in cellular metabolism in all domains... (Review)
Review
Enzymes that use thiamin diphosphate (ThDP), the biologically active derivative of vitamin B1, as a cofactor play important roles in cellular metabolism in all domains of life. The analysis of ThDP enzymes in the past decades have provided a general framework for our understanding of enzyme catalysis of this protein family. In this review, we will discuss recent advances in the field that include the observation of "unusual" reactions and reaction intermediates that highlight the chemical versatility of the thiamin cofactor. Further topics cover the structural basis of cooperativity of ThDP enzymes, novel insights into the mechanism and structure of selected enzymes, and the discovery of "superassemblies" as reported, for example, acetohydroxy acid synthase. Finally, we summarize recent findings in the structural organisation and mode of action of 2-keto acid dehydrogenase multienzyme complexes and discuss future directions of this exciting research field.
Topics: Acetolactate Synthase; Diphosphates; Multienzyme Complexes; Oxidoreductases; Thiamine; Thiamine Pyrophosphate
PubMed: 35988322
DOI: 10.1016/j.sbi.2022.102441