How glycosylation affects glycosylation: the role of N-glycans in glycosyltransferase activity

Glycobiology ◽  
2020 ◽  
Vol 30 (12) ◽  
pp. 941-969 ◽  
Author(s):  
Krzysztof Mikolajczyk ◽  
Radoslaw Kaczmarek ◽  
Marcin Czerwinski
Keyword(s):  
Posttranslational Modifications ◽  
Intracellular Localization ◽  
Profound Impact ◽  
Full Activity ◽  
New Therapy ◽  
Complex Group ◽  
Growing Body

Abstract N-glycosylation is one of the most important posttranslational modifications of proteins. It plays important roles in the biogenesis and functions of proteins by influencing their folding, intracellular localization, stability and solubility. N-glycans are synthesized by glycosyltransferases, a complex group of ubiquitous enzymes that occur in most kingdoms of life. A growing body of evidence shows that N-glycans may influence processing and functions of glycosyltransferases, including their secretion, stability and substrate/acceptor affinity. Changes in these properties may have a profound impact on glycosyltransferase activity. Indeed, some glycosyltransferases have to be glycosylated themselves for full activity. N-glycans and glycosyltransferases play roles in the pathogenesis of many diseases (including cancers), so studies on glycosyltransferases may contribute to the development of new therapy methods and novel glycoengineered enzymes with improved properties. In this review, we focus on the role of N-glycosylation in the activity of glycosyltransferases and attempt to summarize all available data about this phenomenon.

scholarly journals New Insights into the Role of miR-29a in Hepatocellular Carcinoma: Implications in Mechanisms and Theragnostics

2021 ◽  
Vol 11 (3) ◽  
pp. 219
Author(s):  
Ya-Ling Yang ◽  
Yen-Hsiang Chang ◽  
Chia-Jung Li ◽  
Ying-Hsien Huang ◽  
Ming-Chao Tsai ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Tumor Microenvironment ◽  
Crucial Role ◽  
Human Cancer ◽  
Metabolic Adaptation ◽  
Advanced Hcc ◽  
Diagnosis And Prognosis ◽  
Competitive Endogenous Rnas ◽  
Growing Body

Hepatocellular carcinoma (HCC) remains one of the most lethal human cancer globally. For advanced HCC, curable plan for advanced HCC is yet to be established, and the prognosis remains poor. The detail mechanisms underlying the progression of HCC tumorigenicity and the corruption of tumor microenvironment (TME) is complex and inconclusive. A growing body of studies demonstrate microRNAs (miRs) are important regulators in the tumorigenicity and TME development. Notably, mounting evidences indicate miR-29a play a crucial role in exerting hepatoprotective effect on various types of stress and involved in the progression of HCC, which elucidates their potential theragnostic implications. In this review, we reviewed the advanced insights into the detail mechanisms by which miR-29a dictates carcinogenesis, epigenetic program, and metabolic adaptation, and implicated in the sponging activity of competitive endogenous RNAs (ceRNA) and the TME components in the scenario of HCC. Furthermore, we highlighted its clinical significance in diagnosis and prognosis, as well as the emerging therapeutics centered on the activation of miR-29a.

scholarly journals Site-specific ubiquitylation acts as a regulator of linker histone H1

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Höllmüller ◽  
Simon Geigges ◽  
Marie L. Niedermeier ◽  
Kai-Michael Kammer ◽  
Simon M. Kienle ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Histone H1 ◽  
Linker Histone ◽  
Active Chromatin ◽  
Site Specific ◽  
Linker Histone H1 ◽  
Fundamental Process ◽  
Core Histones ◽  
Wide Scale

AbstractDecoding the role of histone posttranslational modifications (PTMs) is key to understand the fundamental process of epigenetic regulation. This is well studied for PTMs of core histones but not for linker histone H1 in general and its ubiquitylation in particular due to a lack of proper tools. Here, we report on the chemical synthesis of site-specifically mono-ubiquitylated H1.2 and identify its ubiquitin-dependent interactome on a proteome-wide scale. We show that site-specific ubiquitylation of H1 at position K64 modulates interactions with deubiquitylating enzymes and the deacetylase SIRT1. Moreover, it affects H1-dependent chromatosome assembly and phase separation resulting in a more open chromatosome conformation generally associated with a transcriptionally active chromatin state. In summary, we propose that site-specific ubiquitylation plays a general regulatory role for linker histone H1.

An Examination of Women's Perspectives on Power

1992 ◽  
Vol 16 (4) ◽  
pp. 415-428 ◽  
Author(s):  
Cynthia L. Miller ◽  
A. Gaye Cummins
Keyword(s):  
Women’S Experiences ◽  
Body Of Knowledge ◽  
Women's Experiences ◽  
Growing Body ◽  
Personal Authority ◽  
Women’S Perceptions ◽  
Definition Of ◽  
Men's Experience ◽  
The Way

Historically, theoretical and popular conceptions about power have not included or addressed women's experiences. This study adds to the growing body of knowledge about women by examining women's perceptions of and relationship to power. One hundred twenty-five women, ranging in age from 21 to 63, were asked to define and explore power through a variety of structured and open-ended questions. The results showed that women's definition of power differed significantly from their perception of society's definition of power, as well as from the way power has traditionally been conceptualized. More theoretical and empirical attention should be given to understanding the role of personal authority in both women's and men's experience of power.

Study abroad and the SLA of variable structures: A look at the present perfect, the copula contrast, and the present progressive in Mexico and Spain

Probus ◽  
2015 ◽  
Vol 27 (2) ◽  
Author(s):  
Matthew Kanwit ◽  
Kimberly L. Geeslin ◽  
Stephen Fafulas
Keyword(s):  
Study Abroad ◽  
Language Learning ◽  
Native Speakers ◽  
L2 Acquisition ◽  
Present Perfect ◽  
Immersion Programs ◽  
Growing Body ◽  
English Speaking ◽  
Grammatical Structures

AbstractThe present study connects research on the L2 acquisition of variable structures to the ever-growing body of research on the role of study abroad in the language learning process. The data come from a group of 46 English-speaking learners of Spanish who participated in immersion programs in two distinct locations, Valencia, Spain and San Luis Potosí, Mexico. Simultaneously, we tested a group of native speakers from each region to create an appropriate target model for each learner group. Learners completed a written contextualized questionnaire at the beginning and end of their seven-week stay abroad. Our instrument examines three variable grammatical structures: (1) the copulas

scholarly journals Epigenetic regulation by the menin pathway

2017 ◽  
Vol 24 (10) ◽  
pp. T147-T159 ◽  
Author(s):  
Zijie Feng ◽  
Jian Ma ◽  
Xianxin Hua
Keyword(s):  
Transcription Factors ◽  
Cell Signaling ◽  
Signaling Pathways ◽  
Gene Transcription ◽  
Epigenetic Regulation ◽  
Posttranslational Modifications ◽  
Genetic Model ◽  
Mirna Biogenesis ◽  
Endocrine Organs

There is a trend of increasing prevalence of neuroendocrine tumors (NETs), and the inherited multiple endocrine neoplasia type 1 (MEN1) syndrome serves as a genetic model to investigate how NETs develop and the underlying mechanisms. Menin, encoded by the MEN1 gene, at least partly acts as a scaffold protein by interacting with multiple partners to regulate cellular homeostasis of various endocrine organs. Menin has multiple functions including regulation of several important signaling pathways by controlling gene transcription. Here, we focus on reviewing the recent progress in elucidating the key biochemical role of menin in epigenetic regulation of gene transcription and cell signaling, as well as posttranslational regulation of menin itself. In particular, we will review the progress in studying structural and functional interactions of menin with various histone modifiers and transcription factors such as MLL, PRMT5, SUV39H1 and other transcription factors including c-Myb and JunD. Moreover, the role of menin in regulating cell signaling pathways such as TGF-beta, Wnt and Hedgehog, as well as miRNA biogenesis and processing will be described. Further, the regulation of the MEN1 gene transcription, posttranslational modifications and stability of menin protein will be reviewed. These various modes of regulation by menin as well as regulation of menin by various biological factors broaden the view regarding how menin controls various biological processes in neuroendocrine organ homeostasis.

scholarly journals The Role of Posttranslational Modifications in DNA Repair

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Miaomiao Bai ◽  
Dongdong Ti ◽  
Qian Mei ◽  
Jiejie Liu ◽  
Xin Yan ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Protein Interactions ◽  
Posttranslational Modifications ◽  
Genome Stability ◽  
Protein Localization ◽  
Complex Structure ◽  
Protein Protein Interactions ◽  
Regulate Protein

The human body is a complex structure of cells, which are exposed to many types of stress. Cells must utilize various mechanisms to protect their DNA from damage caused by metabolic and external sources to maintain genomic integrity and homeostasis and to prevent the development of cancer. DNA damage inevitably occurs regardless of physiological or abnormal conditions. In response to DNA damage, signaling pathways are activated to repair the damaged DNA or to induce cell apoptosis. During the process, posttranslational modifications (PTMs) can be used to modulate enzymatic activities and regulate protein stability, protein localization, and protein-protein interactions. Thus, PTMs in DNA repair should be studied. In this review, we will focus on the current understanding of the phosphorylation, poly(ADP-ribosyl)ation, ubiquitination, SUMOylation, acetylation, and methylation of six typical PTMs and summarize PTMs of the key proteins in DNA repair, providing important insight into the role of PTMs in the maintenance of genome stability and contributing to reveal new and selective therapeutic approaches to target cancers.

scholarly journals Labour Politics in a Naval Dockyard: The Case of Karlskrona, Sweden c. 1880–1925

2001 ◽  
Vol 46 (3) ◽  
pp. 341-369 ◽  
Author(s):  
Mary Hilson
Keyword(s):  
Working Conditions ◽  
Division Of Labour ◽  
Shipbuilding Industry ◽  
Improve Working ◽  
Labour Relations ◽  
Growing Body ◽  
State Employees ◽  
Military Discipline ◽  
Unique Relationship

Naval dockyards have been largely neglected by labour historians, a surprising omission given their importance as industrial workplaces with a distinct culture of labour and labour relations. This article considers labour politics in Karlskrona dockyard, Sweden, in the light of a growing body of research on work and labour relations in the British and other European dockyards. Evidence from Karlskrona suggests that, rather than being repressed by military discipline or bought off by generous state benefits, the dockyard workforce drew on aspects of its unique relationship with the national state to improve working conditions. Particular attention is given to the role of the dockyard trade union in creating a sense of workforce identity as state employees. This is in contrast to the British dockyards where unionism was founded on the rigid division of labour in the shipbuilding industry.

scholarly journals Expression of Mycobacterium smegmatisPyrazinamidase in Mycobacterium tuberculosis Confers Hypersensitivity to Pyrazinamide and Related Amides

2000 ◽  
Vol 182 (19) ◽  
pp. 5479-5485 ◽  
Author(s):  
Helena I. M. Boshoff ◽  
Valerie Mizrahi
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Intracellular Localization ◽  
Wild Type ◽  
Gene Encoding ◽  
Allelic Exchange ◽  
Mutant Strains ◽  
Established Role ◽  
Amidase Gene

ABSTRACT A pyrazinamidase (PZase)-deficient pncA mutant ofMycobacterium tuberculosis, constructed by allelic exchange, was used to investigate the effects of heterologous amidase gene expression on the susceptibility of this organism to pyrazinamide (PZA) and related amides. The mutant was highly resistant to PZA (MIC, >2,000 μg/ml), in accordance with the well-established role ofpncA in the PZA susceptibility of M. tuberculosis (A. Scorpio and Y. Zhang, Nat. Med. 2:662–667, 1996). Integration of the pzaA gene encoding the major PZase/nicotinamidase from Mycobacterium smegmatis (H. I. M. Boshoff and V. Mizrahi, J. Bacteriol. 180:5809–5814, 1998) or the M. tuberculosis pncA gene into the pncAmutant complemented its PZase/nicotinamidase defect. In bothpzaA- and pncA-complemented mutant strains, the PZase activity was detected exclusively in the cytoplasm, suggesting an intracellular localization for PzaA and PncA. ThepzaA-complemented strain was hypersensitive to PZA (MIC, ≤10 μg/ml) and nicotinamide (MIC, ≥20 μg/ml) and was also sensitive to benzamide (MIC, 20 μg/ml), unlike the wild-type andpncA-complemented mutant strains, which were highly resistant to this amide (MIC, >500 μg/ml). This finding was consistent with the observation that benzamide is hydrolyzed by PzaA but not by PncA. Overexpression of PzaA also conferred sensitivity to PZA, nicotinamide, and benzamide on M. smegmatis (MIC, 150 μg/ml in all cases) and rendered Escherichia colihypersensitive for growth at low pH.

scholarly journals Role of maltase in the utilization of sucrose by Candida albicans

1993 ◽  
Vol 291 (3) ◽  
pp. 765-771 ◽  
Author(s):  
P R Williamson ◽  
M A Huber ◽  
J E Bennett
Keyword(s):  
Candida Albicans ◽  
Intracellular Localization ◽  
Cross Reactivity ◽  
Neutral Sugar ◽  
Sequence Specificity ◽  
Western Blots ◽  
Sds Page ◽  
Molecular Masses ◽  
Kinetics Of

Two isoenzymes of maltase (EC 3.2.1.20) were purified to homogeneity from Candida albicans. Isoenzymes I and II were found to have apparent molecular masses of 63 and 66 kDa on SDS/PAGE with isoelectric points of 5.0 and 4.6 respectively. Both isoenzymes resembled each other in similar N-terminal sequence, specificity for the alpha(1-−>4) glycosidic linkage and immune cross-reactivity on Western blots using a maltase II antigen-purified rabbit antibody. Maltase was induced by growth on sucrose whereas beta-fructofuranosidase activity could not be detected under similar conditions. Maltase I and II were shown to be unglycosylated enzymes by neutral sugar assay, and more than 90% of alpha-glucosidase activity was recoverable from spheroplasts. These data, in combination with other results from this laboratory [Geber, Williamson, Rex, Sweeney and Bennett (1992) J. Bacteriol. 174, 6992-6996] showing lack of a plausible leader sequence in genomic or mRNA transcripts, suggest an intracellular localization of the enzyme. To establish further the mechanism of sucrose assimilation by maltase, the existence of a sucrose-inducible H+/sucrose syn-transporter was demonstrated by (1) the kinetics of sucrose-induced [14C]sucrose uptake, (2) recovery of intact [14C]sucrose from ground cells by t.l.c. and (3) transport of 0.83 mol of H+/mol of [14C]sucrose. In total, the above is consistent with a mechanism whereby sucrose is transported into C. albicans to be hydrolysed by an intracellular maltase.

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