scholarly journals Molecular analysis of two closely related mouse aldehyde dehydrogenase genes: identification of a role for Aldh1, but not Aldh-pb, in the biosynthesis of retinoic acid

1999 ◽  
Vol 339 (2) ◽  
pp. 387-395 ◽  
Author(s):  
Lily C. HSU ◽  
Wen-Chung CHANG ◽  
Ines HOFFMANN ◽  
Gregg DUESTER
Keyword(s):  
Retinoic Acid ◽  
Aldehyde Dehydrogenase ◽  
Sequence Similarity ◽  
Physiological Role ◽  
Acid Synthesis ◽  
Promoter Regions ◽  
High Sequence Similarity ◽  
Xenopus Embryos ◽  
High Amino Acid

Mammalian class I aldehyde dehydrogenase (ALDH1) has been implicated as a retinal dehydrogenase in the biosynthesis of retinoic acid, a modulator of gene expression and cell differentiation. As the first step towards studying the regulation of ALDH1 and its physiological role in the biosynthesis of retinoic acid, mouse ALDH1 cDNA and genomic clones have been characterized. During the cloning process, an additional closely related gene was also isolated and named Aldh-pb, owing to its high amino acid sequence identity (92%) with the rat phenobarbitol-inducible ALDH protein (ALDH-PB). Aldh1 spans about 45 kb in length, whereas Aldh-pb spans about 35 kb. Both genes are composed of 13 exons, and the positions of all the exon/intron boundaries are conserved with those of human ALDH1. The promoter regions of Aldh1 and Aldh-pb demonstrate high sequence similarity with those of human ALDH1 and rat ALDH-PB. Expression of Aldh1 and Aldh-pb is tissue-specific, with mRNAs for both genes being found in the liver, lung and testis, but not in the heart, spleen or muscle. Expression of Aldh-pb, but not Aldh1, was also detected at high levels in the kidney. Aldh1 and Aldh-pb encode proteins of 501 amino acids with 90% positional identity. To examine the relative roles of these two enzymes in retinoic acid synthesis in vivo, Xenopus embryos were injected with mRNAs encoding these enzymes to assay the effect on conversion of endogenous retinal into retinoic acid. Injection of ALDH1, but not ALDH-PB, mRNA stimulated retinoic acid synthesis in Xenopus embryos at the blastula stage. Thus our results indicate that Aldh1 can function in retinoic acid synthesis under physiological conditions, but that the closely related Aldh-pb does not share this property.

scholarly journals Insights into Transcriptional Repression of the Homologous Toxin-Antitoxin Cassettes yefM-yoeB and axe-txe

2020 ◽  
Vol 21 (23) ◽  
pp. 9062
Author(s):  
Barbara Kędzierska ◽  
Katarzyna Potrykus ◽  
Agnieszka Szalewska-Pałasz ◽  
Beata Wodzikowska
Keyword(s):  
Transcriptional Repression ◽  
Transcription Initiation ◽  
Sequence Similarity ◽  
In Vitro Transcription ◽  
High Sequence Similarity ◽  
Sequence Composition ◽  
Repressor Complex ◽  
Transcriptional Fusions

Transcriptional repression is a mechanism which enables effective gene expression switch off. The activity of most of type II toxin-antitoxin (TA) cassettes is controlled in this way. These cassettes undergo negative autoregulation by the TA protein complex which binds to the promoter/operator sequence and blocks transcription initiation of the TA operon. Precise and tight control of this process is vital to avoid uncontrolled expression of the toxin component. Here, we employed a series of in vivo and in vitro experiments to establish the molecular basis for previously observed differences in transcriptional activity and repression levels of the pyy and pat promoters which control expression of two homologous TA systems, YefM-YoeB and Axe-Txe, respectively. Transcriptional fusions of promoters with a lux reporter, together with in vitro transcription, EMSA and footprinting assays revealed that: (1) the different sequence composition of the −35 promoter element is responsible for substantial divergence in strengths of the promoters; (2) variations in repression result from the TA repressor complex acting at different steps in the transcription initiation process; (3) transcription from an additional promoter upstream of pat also contributes to the observed inefficient repression of axe-txe module. This study provides evidence that even closely related TA cassettes with high sequence similarity in the promoter/operator region may employ diverse mechanisms for transcriptional regulation of their genes.

scholarly journals NDE1 and NDEL1: twin neurodevelopmental proteins with similar ‘nature’ but different ‘nurture’

2013 ◽  
Vol 4 (5) ◽  
pp. 447-464 ◽  
Author(s):  
Nicholas J. Bradshaw ◽  
William Hennah ◽  
Dinesh C. Soares
Keyword(s):  
Neurodevelopmental Disorders ◽  
Sequence Similarity ◽  
Review Of The Literature ◽  
Post Translational Modification ◽  
Similar Nature ◽  
High Sequence Similarity ◽  
Basic Functions ◽  
Key Aspects ◽  
Paralogous Proteins

AbstractNuclear distribution element 1 (NDE1, also known as NudE) and NDE-like 1 (NDEL1, also known as Nudel) are paralogous proteins essential for mitosis and neurodevelopment that have been implicated in psychiatric and neurodevelopmental disorders. The two proteins possess high sequence similarity and have been shown to physically interact with one another. Numerous lines of experimental evidence in vivo and in cell culture have demonstrated that these proteins share common functions, although instances of differing functions between the two have recently emerged. We review the key aspects of NDE1 and NDEL1 in terms of recent advances in structure elucidation and cellular function, with an emphasis on their differing mechanisms of post-translational modification. Based on a review of the literature and bioinformatics assessment, we advance the concept that the twin proteins NDE1 and NDEL1, while sharing a similar ‘nature’ in terms of their structure and basic functions, appear to be different in their ‘nurture’, the manner in which they are regulated both in terms of expression and of post-translational modification within the cell. These differences are likely to be of significant importance in understanding the specific roles of NDE1 and NDEL1 in neurodevelopment and disease.

scholarly journals A double-stranded RNA-inducible fish gene homologous to the murine influenza virus resistance gene Mx.

1989 ◽  
Vol 9 (7) ◽  
pp. 3117-3121 ◽  
Author(s):  
P Staeheli ◽  
Y X Yu ◽  
R Grob ◽  
O Haller
Keyword(s):  
Influenza Virus ◽  
Resistance Gene ◽  
Virus Resistance ◽  
Genomic Dna ◽  
Sequence Similarity ◽  
Perca Fluviatilis ◽  
High Sequence Similarity ◽  
Double Stranded Rna ◽  
Virus Resistance Gene

We cloned and sequenced a 2.35-kilobase EcoRI fragment of genomic DNA from a local freshwater fish (Perca fluviatilis) that strongly hybridized to probes derived from the murine influenza virus resistance gene Mx. The cloned fish DNA contained blocks of sequences related to Mx gene exons 3 to 8, which appeared to represent exons of a bona fide fish gene because they were separated by intron sequences flanked by consensus splice acceptor and donor sites. Injection of double-stranded RNA into the peritoneal cavity of trouts resulted in 5- to 10-fold elevated levels of two liver mRNAs of about 2.0 to 2.5 kilobases in length that hybridized to the cloned genomic DNA. High sequence similarity between this fish gene and the murine Mx gene, identical exon lengths, and similar inducibilities in vivo by double-stranded RNA indicate that we isolated a fragment of a fish Mx gene.

scholarly journals Identification of a d-Arabinose-5-Phosphate Isomerase in the Gram-Positive Clostridium tetani

2017 ◽  
Vol 199 (17) ◽  
Author(s):  
David L. Cech ◽  
Katherine Markin ◽  
Ronald W. Woodard
Keyword(s):  
Sequence Similarity ◽  
Physiological Role ◽  
Gram Negative Bacteria ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Clostridium Tetani ◽  
High Sequence Similarity ◽  
Gram Negative ◽  
Content Type ◽  
Sugar Phosphates

ABSTRACT d-Arabinose-5-phosphate (A5P) isomerases (APIs) catalyze the interconversion of d-ribulose-5-phosphate and d-arabinose-5-phosphate. Various Gram-negative bacteria, such as the uropathogenic Escherichia coli strain CFT073, contain multiple API paralogs (KdsD, GutQ, KpsF, and c3406) that have been assigned various cellular functions. The d-arabinose-5-phosphate formed by these enzymes seems to play important roles in the biosynthesis of lipopolysaccharide (LPS) and group 2 K-antigen capsules, as well as in the regulation of the cellular d-glucitol uptake and uropathogenic infectivity/virulence. The genome of a Gram-positive pathogenic bacterium, Clostridium tetani, contains a gene encoding a putative API, C. tetani API (CtAPI), even though C. tetani lacks both LPS and capsid biosynthetic genes. To better understand the physiological role of d-arabinose-5-phosphate in this Gram-positive organism, recombinant CtAPI was purified and characterized. CtAPI displays biochemical characteristics similar to those of APIs from Gram-negative organisms and complements the API deficiency of an E. coli API knockout strain. Thus, CtAPI represents the first d-arabinose-5-phosphate isomerase to be identified and characterized from a Gram-positive bacterium. IMPORTANCE The genome of Clostridium tetani, a pathogenic Gram-positive bacterium and the causative agent of tetanus, contains a gene (the CtAPI gene) that shares high sequence similarity with those of genes encoding d-arabinose-5-phosphate isomerases. APIs play an important role within Gram-negative bacteria in d-arabinose-5-phosphate production for lipopolysaccharide biosynthesis, capsule formation, and regulation of cellular d-glucitol uptake. The significance of our research is in identifying and characterizing CtAPI, the first Gram-positive API. Our findings show that CtAPI is specific to the interconversion of arabinose-5-phosphate and ribulose-5-phosphate while having no activity with the other sugars and sugar phosphates tested. We have speculated a regulatory role for this API in C. tetani, an organism that does not produce lipopolysaccharide.

scholarly journals Long-lasting Analgesia via Targetedin vivoEpigenetic Repression of Nav1.7

2019 ◽  
Author(s):  
Ana M. Moreno ◽  
Glaucilene F. Catroli ◽  
Fernando Alemán ◽  
Andrew Pla ◽  
Sarah A. Woller ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Genome Engineering ◽  
Therapeutic Potential ◽  
Sequence Similarity ◽  
Thermal Hyperalgesia ◽  
Loss Of Function ◽  
High Sequence Similarity ◽  
Inflammatory State

ABSTRACTCurrent treatments for chronic pain rely largely on opioids despite their unwanted side effects and risk of addiction. Genetic studies have identified in humans key targets pivotal to nociceptive processing, with the voltage-gated sodium channel, NaV1.7 (SCN9A), being perhaps the most promising candidate for analgesic drug development. Specifically, a hereditary loss-of-function mutation in NaV1.7 leads to insensitivity to pain without other neurodevelopmental alterations. However, the high sequence similarity between NaVsubtypes has frustrated efforts to develop selective inhibitors. Here, we investigated targeted epigenetic repression of NaV1.7 via genome engineering approaches based on clustered regularly interspaced short palindromic repeats (CRISPR)-dCas9 and zinc finger proteins as a potential treatment for chronic pain. Towards this end, we first optimized the efficiency of NaV1.7 repressionin vitroin Neuro2A cells, and then by the lumbar intrathecal route delivered both genome-engineering platforms via adeno-associated viruses (AAVs) to assess their effects in three mouse models of pain: carrageenan-induced inflammatory pain, paclitaxel-induced neuropathic pain and BzATP-induced pain. Our results demonstrate: one, effective repression of NaV1.7 in lumbar dorsal root ganglia; two, reduced thermal hyperalgesia in the inflammatory state; three, decreased tactile allodynia in the neuropathic state; and four, no changes in normal motor function. We anticipate this genomically scarless and non-addictivepainamelioration approach enablingLong-lastingAnalgesia viaTargetedin vivoEpigeneticRepression of Nav1.7, a methodology we dubpain LATER, will have significant therapeutic potential, such as for preemptive administration in anticipation of a pain stimulus (pre-operatively), or during an established chronic pain state.One sentence summaryIn situepigenome engineering approach for genomically scarless, durable, and non-addictive management of pain.

scholarly journals PPARγ controls CD1d expression by turning on retinoic acid synthesis in developing human dendritic cells

2006 ◽  
Vol 203 (10) ◽  
pp. 2351-2362 ◽  
Author(s):  
Istvan Szatmari ◽  
Attila Pap ◽  
Ralph Rühl ◽  
Jiang-Xing Ma ◽  
Petr A. Illarionov ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dendritic Cells ◽  
Retinoic Acid ◽  
Antigen Presentation ◽  
Cell Activation ◽  
Acid Synthesis ◽  
Inkt Cell ◽  
Peroxisome Proliferator ◽  
Lipid Antigen

Dendritic cells (DCs) expressing CD1d, a molecule responsible for lipid antigen presentation, are capable of enhancing natural killer T (iNKT) cell proliferation. The signals controlling CD1 expression and lipid antigen presentation are poorly defined. We have shown previously that stimulation of the lipid-activated transcription factor, peroxisome proliferator-activated receptor (PPAR)γ, indirectly regulates CD1d expression. Here we demonstrate that PPARγ, turns on retinoic acid synthesis by inducing the expression of retinol and retinal metabolizing enzymes such as retinol dehydrogenase 10 and retinaldehyde dehydrogenase type 2 (RALDH2). PPARγ-regulated expression of these enzymes leads to an increase in the intracellular generation of all-trans retinoic acid (ATRA) from retinol. ATRA regulates gene expression via the activation of the retinoic acid receptor (RAR)α in human DCs, and RARα acutely regulates CD1d expression. The retinoic acid–induced elevated expression of CD1d is coupled to enhanced iNKT cell activation. Furthermore, in vivo relevant lipids such as oxidized low-density lipoprotein can also elicit retinoid signaling leading to CD1d up-regulation. These data show that regulation of retinoid metabolism and signaling is part of the PPARγ-controlled transcriptional events in DCs. The uncovered mechanisms allow the DCs to respond to altered lipid homeostasis by changing CD1 gene expression.

scholarly journals Retinoic acid upregulates β1-integrin in vascular smooth muscle cells and alters adhesion to fibronectin

2000 ◽  
Vol 279 (1) ◽  
pp. H382-H387 ◽  
Author(s):  
Meetha M. Medhora
Keyword(s):  
Smooth Muscle ◽  
Retinoic Acid ◽  
Vascular Smooth Muscle ◽  
Blood Vessels ◽  
Physiological Role ◽  
Cellular Growth ◽  
Integrin Subunit ◽  
Adult Rats ◽  
Functional Changes

Retinoic acid has an established physiological role in differentiation, development, and cellular growth. This study investigated the action of all- trans retinoic acid (ATRA) on vascular integrins, cell-surface receptors that control growth and remodeling of blood vessels. The β1-integrin subunit mRNA and protein was induced after treatment with ATRA in two different rat vascular smooth muscle cell lines. To relate this result to the in vivo state, the aortas from adult rats fed with therapeutic doses of ATRA were examined for β1-integrin protein. A significant upregulation of the integrin subunit was observed in vivo. To assess if this increase contributed to physiological changes in cellular function, cells treated with ATRA were tested for alterations in adhesion to extracellular matrix proteins. The cells exposed to the retinoid were seen to adhere more strongly to fibronectin, via the β1-integrin. These results showed that modulation of vascular integrins by ATRA in adult rats contributes to functional changes that can cause remodeling of blood vessels.

scholarly journals Viral Hormones: Expanding Dimensions in Endocrinology

Endocrinology ◽  
2019 ◽  
Vol 160 (9) ◽  
pp. 2165-2179 ◽  
Author(s):  
Qian Huang ◽  
C Ronald Kahn ◽  
Emrah Altindis
Keyword(s):  
Dna Sequences ◽  
Sequence Similarity ◽  
Endocrine System ◽  
Peptide Hormones ◽  
Rna Sequences ◽  
High Sequence Similarity ◽  
In Vivo Models ◽  
Viral Mimicry

AbstractViruses have developed different mechanisms to manipulate their hosts, including the process of viral mimicry in which viruses express important host proteins. Until recently, examples of viral mimicry were limited to mimics of growth factors and immunomodulatory proteins. Using a comprehensive bioinformatics approach, we have shown that viruses possess the DNA/RNA with potential to encode 16 different peptides with high sequence similarity to human peptide hormones and metabolically important regulatory proteins. We have characterized one of these families, the viral insulin/IGF-1–like peptides (VILPs), which we identified in four members of the Iridoviridae family. VILPs can bind to human insulin and IGF-1 receptors and stimulate classic postreceptor signaling pathways. Moreover, VILPs can stimulate glucose uptake in vitro and in vivo and stimulate DNA synthesis. DNA sequences of some VILP-carrying viruses have been identified in the human enteric virome. In addition to VILPs, sequences with homology to 15 other peptide hormones or cytokines can be identified in viral DNA/RNA sequences, some with a very high identity to hormones. Recent data by others has identified a peptide that resembles and mimics α-melanocyte-stimulating hormone’s anti-inflammatory effects in in vitro and in vivo models. Taken together, these studies reveal novel mechanisms of viral and bacterial pathogenesis in which the microbe can directly target or mimic the host endocrine system. These findings also introduce the concept of a system of microbial hormones that provides new insights into the evolution of peptide hormones, as well as potential new roles of microbial hormones in health and disease.

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