scholarly journals Tissue-Specific Regulation of HNK-1 Biosynthesis by Bisecting GlcNAc

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5176
Author(s):  
Haruka Kawade ◽  
Jyoji Morise ◽  
Sushil K. Mishra ◽  
Shuta Tsujioka ◽  
Shogo Oka ◽  
...  
Keyword(s):  
Dynamics Simulation ◽  
The Novel ◽  
Tissue Specific ◽  
Synaptic Functions ◽  
The Difference ◽  
Specific Regulation ◽  
The Brain ◽  
Bisecting Glcnac

Human natural killer—1 (HNK-1) is a sulfated glyco-epitope regulating cell adhesion and synaptic functions. HNK-1 and its non-sulfated forms, which are specifically expressed in the brain and the kidney, respectively, are distinctly biosynthesized by two homologous glycosyltransferases: GlcAT-P in the brain and GlcAT-S in the kidney. However, it is largely unclear how the activity of these isozymes is regulated in vivo. We recently found that bisecting GlcNAc, a branching sugar in N-glycan, suppresses both GlcAT-P activity and HNK-1 expression in the brain. Here, we observed that the expression of non-sulfated HNK-1 in the kidney is unexpectedly unaltered in mutant mice lacking bisecting GlcNAc. This suggests that the biosynthesis of HNK-1 in the brain and the kidney are differentially regulated by bisecting GlcNAc. Mechanistically, in vitro activity assays demonstrated that bisecting GlcNAc inhibits the activity of GlcAT-P but not that of GlcAT-S. Furthermore, molecular dynamics simulation showed that GlcAT-P binds poorly to bisected N-glycan substrates, whereas GlcAT-S binds similarly to bisected and non-bisected N-glycans. These findings revealed the difference of the highly homologous isozymes for HNK-1 synthesis, highlighting the novel mechanism of the tissue-specific regulation of HNK-1 synthesis by bisecting GlcNAc.

Cyclin A1 directly interacts with B-myb and cyclin A1/cdk2 phosphorylate B-myb at functionally important serine and threonine residues: tissue-specific regulation of B-myb function

Blood ◽  
2001 ◽  
Vol 97 (7) ◽  
pp. 2091-2097 ◽  
Author(s):  
Carsten Müller-Tidow ◽  
Wenbing Wang ◽  
Gregory E. Idos ◽  
Sven Diederichs ◽  
Rong Yang ◽  
...  
Keyword(s):  
Leukemic Cells ◽  
Glutathione S Transferase ◽  
Cyclin A1 ◽  
Tissue Specific ◽  
Cdk2 Complex ◽  
Cyclin A2 ◽  
Specific Regulation ◽  
Phosphopeptide Mapping

Abstract Cyclin A1 is tissue-specifically expressed during spermatogenesis, but it is also highly expressed in acute myeloid leukemia (AML). Its pathogenetic role in AML and in the cell cycle of leukemic blasts is unknown. B-myb is essential for G1/S transition and has been shown to be phosphorylated by the cyclin A2/cdk2 complex. Here it is demonstrated that cyclin A1 interacts with the C-terminal portion of B-myb as shown by glutathione S-transferase (GST) precipitation. This interaction is confined to cyclin A1 because binding could not be detected between cyclin A2 and B-myb. Also, cdk2 was not pulled down by GST–B-myb from U937 lysates. In addition, co-immunoprecipitation of cyclin A1 and B-myb in leukemic cells evidenced protein interaction in vivo. Baculovirus-expressed cyclin A1/cdk2 complexes were able to phosphorylate human as well as murine B-myb in vitro. Tryptic phosphopeptide mapping revealed that cyclin A1/cdk2 complexes phosphorylated the C-terminal part of B-myb at several sites including threonine 447, 490, and 497 and serine 581. These phosphorylation sites have been demonstrated to be important for the enhancement of B-myb transcriptional activity. Further studies showed that cyclin A1 cooperated with B-myb to transactivate myb binding site containing promoters including the promoter of the human cyclin A1 gene. Taken together, the data suggest that cyclin A1 is a tissue-specific regulator of B-myb function and activates B-myb in leukemic blasts.

scholarly journals Homeoproteins CDP and SATB1 Interact: Potential for Tissue-Specific Regulation

1999 ◽  
Vol 19 (7) ◽  
pp. 4918-4926 ◽  
Author(s):  
Jinqi Liu ◽  
Anna Barnett ◽  
Ellis J. Neufeld ◽  
Jaquelin P. Dudley
Keyword(s):  
T Cells ◽  
Dna Binding ◽  
Promoter Region ◽  
Cell Type ◽  
Tissue Specific ◽  
Specific Antisera ◽  
Mmtv Promoter ◽  
Specific Regulation

ABSTRACT Homeoproteins are known to participate in development and cell type specification. The homeoproteins CCAAT displacement protein (CDP) and special AT-rich sequence binding protein 1 (SATB1) have been shown to bind to nuclear matrix-associated regions and to act as repressors of many cellular genes. Moreover, binding of SATB1 to the mouse mammary tumor virus (MMTV) promoter region dramatically affects the tissue-specific transcription of this retrovirus. Because protein-protein interactions are a common means of regulating homeoprotein function, we tested whether SATB1 and CDP interact in vivo and in vitro. SATB1 interacted with CDP through its DNA-binding domain, as demonstrated by glutathione S-transferase (GST) pull-down assays. GST pull-down assays also showed that CDP associated with SATB1 through three of its four DNA-binding domains (CR1, CR2, and the homeodomain). SATB1-specific antisera, but not preimmune sera, precipitated CDP from nuclear extracts, and CDP-specific antisera precipitated SATB1 from the same extracts. Far-Western blotting detected interaction of SATB1 and CDP in several different tissue extracts. Association of purified SATB1 and CDP in vitro resulted in the inability of each protein to bind to DNA in gel retardation assays. CDP overexpression in cultured T cells led to a loss of detectable SATB1 binding to the MMTV promoter region, as measured by gel shift experiments. CDP overexpression also elevated MMTV long terminal repeat reporter gene activity in transient-transfection assays, a result consistent with neutralization of the SATB1 repressor function in T cells. SATB1 is very abundant in certain tissues, particularly thymus, whereas CDP is relatively ubiquitous, except in certain terminally differentiated cell types. Because of the tissue and cell type distribution of SATB1 and CDP, we propose that the SATB1-to-CDP ratio in different tissues is a novel mechanism for homeoproteins to control gene expression and differentiation in mammals.

Tissue-specific gene expression of prolactin receptor in the acute-phase response induced by lipopolysaccharides

2004 ◽  
Vol 287 (4) ◽  
pp. E750-E757 ◽  
Author(s):  
Ana M. Corbacho ◽  
Giuseppe Valacchi ◽  
Lukas Kubala ◽  
Estibaliz Olano-Martín ◽  
Bettina C. Schock ◽  
...  
Keyword(s):  
Acute Phase ◽  
Acute Phase Response ◽  
Prolactin Receptor ◽  
Phase Response ◽  
Specific Gene ◽  
Mrna Levels ◽  
Tissue Specific ◽  
Specific Regulation

Acute inflammation can elicit a defense reaction known as the acute-phase response (APR) that is crucial for reestablishing homeostasis in the host. The role for prolactin (PRL) as an immunomodulatory factor maintaining homeostasis under conditions of stress has been proposed; however, its function during the APR remains unclear. Previously, it was shown that proinflammatory cytokines characteristic of the APR (TNF-α, IL-1β, and IFNγ) induced the expression of the PRL receptor (PRLR) by pulmonary fibroblasts in vitro. Here, we investigated the in vivo expression of PRLR during lipopolysaccharide (LPS)-induced APR in various tissues of the mouse. We show that PRLR mRNA and protein levels were downregulated in hepatic tissues after intraperitoneal LPS injection. Downregulation of PRLR in the liver was confirmed by immunohistochemistry. A suppressive effect on mRNA expression was also observed in prostate, seminal vesicle, kidney, heart, and lung tissues. However, PRLR mRNA levels were increased in the thymus, and no changes were observed in the spleen. The proportion of transcripts for the different receptor isoforms (long, S1, S2, and S3) in liver and thymus was not altered by LPS injection. These findings suggest a complex tissue-specific regulation of PRLR expression in the context of the APR.

scholarly journals Tissue-specific H2Bub1 is required for cardiomyocyte development

2021 ◽  
Author(s):  
Syndi Barish ◽  
Jeffrey Drozd ◽  
Kathryn Berg ◽  
Isabella Berglund-Brown ◽  
Labeeqa Khizir ◽  
...  
Keyword(s):  
Heart Development ◽  
De Novo ◽  
Cardiac Development ◽  
General Mechanism ◽  
Transcriptional Elongation ◽  
De Novo Mutations ◽  
Tissue Specific ◽  
Specific Regulation

Abstract De-novo mutations affecting Histone2B-K120 monoubiquitination (H2Bub1) are enriched in congenital heart disease; however, how H2Bub1 affects heart development beyond its function in establishing left-right asymmetry remains unknown. Here we show that the RNF20-core complex (RNF20-RNF40-UBE2B), which catalyzes H2Bub1, is required for cardiac development in-vivo in mice and in-vitro in iPSC-derived cardiomyocytes. Mice with cardiac-specific deletion of Rnf20 have abnormal myocardium and ventricular septal defects; iPSCs with mutations affecting H2Bub1 cannot efficiently differentiate into cardiomyocytes. Sarcomeric gene expression is dependent on normal H2Bub1 both in mice and in iPSC-derived cardiomyocytes. Finally, we identify an accumulation of H2Bub1 near the center of tissue-specific genes in cardiomyocytes and MEFs associated with transcriptional efficiency that is reduced in UBE2B-/- cardiomyocytes. In summary, normal H2Bub1 distribution is required in cardiac development, and H2Bub1 accumulation acts as a general mechanism for tissue-specific regulation of transcriptional elongation efficiency.

scholarly journals Tissue-specific regulation and function of Grb10 during growth and neuronal commitment

2014 ◽  
Vol 112 (22) ◽  
pp. 6841-6847 ◽  
Author(s):  
Robert N. Plasschaert ◽  
Marisa S. Bartolomei
Keyword(s):  
Motor Neurons ◽  
Cellular Proliferation ◽  
Neuronal Development ◽  
Embryonic Stem ◽  
Specific Expression ◽  
Tissue Specific ◽  
Specific Regulation ◽  
And Function

Growth-factor receptor bound protein 10 (Grb10) is a signal adapter protein encoded by an imprinted gene that has roles in growth control, cellular proliferation, and insulin signaling. Additionally, Grb10 is critical for the normal behavior of the adult mouse. These functions are paralleled by Grb10’s unique tissue-specific imprinted expression; the paternal copy of Grb10 is expressed in a subset of neurons whereas the maternal copy is expressed in most other adult tissues in the mouse. The mechanism that underlies this switch between maternal and paternal expression is still unclear, as is the role for paternally expressed Grb10 in neurons. Here, we review recent work and present complementary data that contribute to the understanding of Grb10 gene regulation and function, with specific emphasis on growth and neuronal development. Additionally, we show that in vitro differentiation of mouse embryonic stem cells into alpha motor neurons recapitulates the switch from maternal to paternal expression observed during neuronal development in vivo. We postulate that this switch in allele-specific expression is related to the functional role of Grb10 in motor neurons and other neuronal tissues.

scholarly journals Pharmacoinformatics based elucidation and designing of potential inhibitors against Plasmodium falciparum to target importin α/β mediated nuclear importation

2020 ◽  
Author(s):  
Arafat Rahman Oany ◽  
Tahmina Pervin ◽  
Mohammad Ali Moni
Keyword(s):  
Plasmodium Falciparum ◽  
Dynamics Simulation ◽  
The Novel ◽  
Importin Alpha ◽  
Importin Α ◽  
The Stability ◽  
Potential Inhibitors ◽  
Side Pocket

AbstractPlasmodium falciparum, the prime causative agent of malaria, is responsible for 4, 05,000 deaths per year and fatality rates are higher among the children aged below 5 years. The emerging distribution of the multi-drug resistant P. falciparum becomes a worldwide concern, so the identification of unique targets and novel inhibitors is a prime need now. In the present study, we have employed pharmacoinformatics approaches to analyze 265 lead-like compounds from PubChem databases for virtual screening. Thereafter, 15 lead-like compounds were docked within the active side pocket of importin alpha. Comparative ligand properties and absorption, distribution, metabolism, excretion, and toxicity (ADMET) profile were also assessed. Finally, a novel inhibitor was designed and assessed computationally for its efficacy. From the comparative analysis we have found that our screened compounds possess better results than the existing lead ivermectin; having the highest binding energy of −15.6 kcal/mol, whereas ivermectin has −12.4kcal/mol. The novel lead compound possessed more fascinating output without deviating any of the rules of Lipinski. It also possessed higher bioavailability and the drug-likeness score of 0.55 and 0.71, respectively compared to ivermectin. Furthermore, the binding study was confirmed by molecular dynamics simulation over 25 ns by evaluating the stability of the complex. Finally, all the screened compounds and the novel compound showed promising ADMET properties likewise. To end, we hope that our proposed screened compounds, as well as the novel compound, might give some advances to treat malaria efficiently in vitro and in vivo.

scholarly journals HNF1alpha is involved in tissue-specific regulation of CFTR gene expression

2004 ◽  
Vol 378 (3) ◽  
pp. 909-918 ◽  
Author(s):  
Nathalie MOUCHEL ◽  
Sytse A. HENSTRA ◽  
Victoria A. McCARTHY ◽  
Sarah H. WILLIAMS ◽  
Marios PHYLACTIDES ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Tissue Specificity ◽  
Regulatory Elements ◽  
Upstream Region ◽  
Mrna Levels ◽  
Tissue Specific ◽  
Specific Regulation

The CFTR (cystic fibrosis transmembrane conductance regulator) gene shows a complex pattern of expression with tissue-specific and temporal regulation. However, the genetic elements and transcription factors that control CFTR expression are largely unidentified. The CFTR promoter does not confer tissue specificity on gene expression, suggesting that there are regulatory elements outside the upstream region. Analysis of potential regulatory elements defined as DNase 1-hypersensitive sites within introns of the gene revealed multiple predicted binding sites for the HNF1α (hepatocyte nuclear factor 1α) transcription factor. HNF1α, which is expressed in many of the same epithelial cell types as CFTR and shows similar differentiation-dependent changes in gene expression, bound to these sites in vitro. Overexpression of heterologous HNF1α augmented CFTR transcription in vivo. In contrast, antisense inhibition of HNF1α transcription decreased the CFTR mRNA levels. Hnf1α knockout mice showed lower levels of CFTR mRNA in their small intestine in comparison with wild-type mice. This is the first report of a transcription factor, which confers tissue specificity on the expression of this important disease-associated gene.

scholarly journals Differential Expression of Progestin Receptor Isoforms in the Hypothalamus, Pituitary, and Endometrium of Rhesus Macaques*

Endocrinology ◽  
1998 ◽  
Vol 139 (2) ◽  
pp. 677-687 ◽  
Author(s):  
Cynthia L. Bethea ◽  
Andrea A. Widmann
Keyword(s):  
Differential Expression ◽  
Messenger Rna ◽  
Rhesus Macaques ◽  
Short Form ◽  
Tissue Specific ◽  
Progestin Receptor ◽  
Receptor Isoforms ◽  
Specific Regulation

Abstract The progestin receptor exists in at least two isoforms: a long form (PR-B) and a short form (PR-A), which can be separated and detected with Western blot analysis. It has been suggested from in vitro transfection experiments that differential expression of the two isoforms may provide one mechanism for tissue specific actions of progesterone (P). However, more information from in vivo experimentation is needed. It has been reported that P down-regulates the expression of PR in the endometrium and pituitary of E primed macaques. However, PR protein and PR messenger RNA expression in the hypothalamus is maintained with P treatment of E-primed macaques. Thus, there is tissue-specific regulation of PR by its cognate ligand in the nonhuman primate. To gain insight into the tissue-specific regulation of PR by P, we questioned whether differential expression of the isoforms of PR exists in the endometrium, pituitary, and hypothalamus of rhesus monkeys. The expression of PR-A and PR-B was examined after E (28–30 days) and E + P (14 days E + 14 days E + P) treatment in the primate endometrium, pituitary, and hypothalamus. After E or E + P treatment, the levels of PR-A were 5 times higher than PR-B in the endometrium. PR-A was 1.6-fold higher than PR-B in the pituitary. In the hypothalamus, the ratio of A to B ranged from less than 1 (B exceeds A) to unity (A and B equimolar). There was no difference in the ratio of A to B between E-treated and E + P-treated groups in any tissue examined. These observations (a) provide further support of the hypothesis that differential expression of the isoforms of PR may subserve the tissue specific actions of P and (b) also suggest that P does not differentially affect the expression of the isoforms of its cognate receptor in the endometrium, pituitary, or hypothalamus.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

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