Role of N- and O-glycans in polarized biosynthetic sorting

2006 ◽  
Vol 290 (1) ◽  
pp. C1-C10 ◽  
Author(s):  
Beth A. Potter ◽  
Rebecca P. Hughey ◽  
Ora A. Weisz
Keyword(s):  
Developmental Stage ◽  
Posttranslational Modifications ◽  
Biosynthetic Pathway ◽  
Cell Type ◽  
The Past ◽  
Differentiated Cells ◽  
Sorting Signals ◽  
Targeting Signals ◽  
Apical Sorting

The maintenance of proper epithelial function requires efficient sorting of newly synthesized and recycling proteins to the apical and basolateral surfaces of differentiated cells. Whereas basolateral protein sorting signals are generally confined to their cytoplasmic regions, apical targeting signals have been identified that localize to luminal, transmembrane, and cytoplasmic aspects of proteins. In the past few years, both N- and O-linked glycans have been identified as apical sorting determinants. Glycan structures are extraordinarily diverse and have tremendous information potential. Moreover, because the oligosaccharides added to a given protein can change depending on cell type and developmental stage, the potential exists for altering sorting pathways by modulation of the expression pattern of enzymes involved in glycan synthesis. In this review, we discuss the evidence for glycan-mediated apical sorting along the biosynthetic pathway and present possible mechanisms by which these common and heterogeneous posttranslational modifications might function as specific sorting signals.

scholarly journals Role of N-glycosylation in trafficking of apical membrane proteins in epithelia

2009 ◽  
Vol 296 (3) ◽  
pp. F459-F469 ◽  
Author(s):  
Olga Vagin ◽  
Jeffrey A. Kraut ◽  
George Sachs
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Transporters ◽  
Membrane Domains ◽  
Sorting Signals ◽  
Galectin 3 ◽  
Vectorial Functions ◽  
Apical Sorting ◽  
Golgi Network

Polarized distribution of plasma membrane transporters and receptors in epithelia is essential for vectorial functions of epithelia. This polarity is maintained by sorting of membrane proteins into apical or basolateral transport containers in the trans-Golgi network and/or endosomes followed by their delivery to the appropriate plasma membrane domains. Sorting depends on the recognition of sorting signals in proteins by specific sorting machinery. In the present review, we summarize experimental evidence for and against the hypothesis that N-glycans attached to the membrane proteins can act as apical sorting signals. Furthermore, we discuss the roles of N-glycans in the apical sorting event per se and their contribution to folding and quality control of glycoproteins in the endoplasmic reticulum or retention of glycoproteins in the plasma membrane. Finally, we review existing hypotheses on the mechanism of apical sorting and discuss the potential roles of the lectins, VIP36 and galectin-3, as putative apical sorting receptors.

scholarly journals Inducing your neighbors to become like you: Cell recruitment and its contribution to developmental patterning and growth

2020 ◽  
Vol 52 ◽  
Author(s):  
Luis Manuel Muñoz-Nava ◽  
Marycruz Flores-Flores ◽  
Marcos Nahmad
Keyword(s):  
Specific Cell ◽  
Cell Type ◽  
Recruitment Process ◽  
Cell Recruitment ◽  
Drosophila Wing ◽  
Differentiated Cells ◽  
Open Questions ◽  
Developmental Patterning ◽  
Type Population

Cell differentiation, proliferation, and morphogenesis are generally driven by instructive signals that are sent and interpreted by adjacent tissues, a process known as induction. Cell recruitment is a particular case of induction in which differentiated cells produce a signal that drives adjacent cells to differentiate into the same type as the inducers. Once recruited, these new cells may become inducers to continue the recruitment process, closing a feed-forward loop that propagates the growth of a specific cell-type population. So far, little attention has been given to cell recruitment as a developmental mechanism. Here, we review the components of cell recruitment and discuss its contribution to development in three different examples: the Drosophila wing, the vertebrate inner ear, and the mammalian thyroid gland. Finally, we posit some open questions about the role of cell recruitment in organ patterning and growth.

scholarly journals Role of oxidative stress in facilitating carcinogenesis

2017 ◽  
Vol 5 (3) ◽  
pp. 742
Author(s):  
Venkateswaran Natarajan
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle Progression ◽  
Cell Type ◽  
Cycle Progression ◽  
Cellular Survival ◽  
The Past ◽  
Great Debate ◽  
External Sources ◽  
Negative Role

The carcinogenic role of ROS has been a great debate in the past and will be in the future. ROS is produced by both internal (inflammation) and external sources (UV). ROS is important for various important signalling mechanisms for the normal cellular survival. Even though literature exists to support the role of ROS in cancer, the magnitude of its expression and cell type it is expressed will determine whether it plays a positive (apoptosis) or negative role (genomic instability) in cancer. Apart from inducing DNA damage, ROS facilitates carcinogenesis by regulating cell cycle progression, gap junction, inflammation etc. The present review updates the recent discoveries of how ROS regulates these important cellular signalling mechanisms to facilitate carcinogenesis.

scholarly journals Anthocyanins: Biosynthesis, Distribution, Ecological Role, and Use of Biostimulants to Increase Their Content in Plant Foods—A Review

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 212
Author(s):  
Giuseppe Mannino ◽  
Carla Gentile ◽  
Andrea Ertani ◽  
Graziella Serio ◽  
Cinzia Margherita Bertea
Keyword(s):  
Chemical Structure ◽  
Biosynthetic Pathway ◽  
Physiological Role ◽  
Plant Distribution ◽  
Anthocyanin Synthesis ◽  
Past Century ◽  
Anthocyanin Content ◽  
The Past ◽  
Increasing Demand

In the past century, plant biostimulants have been increasingly used in agriculture as innovative and sustainable practice. Plant biostimulants have been mainly investigated as potential agents able to mitigate abiotic stress. However, few information is available about their ability to influence fruit quality or change fruit phytochemical composition. In particular, very little is known about their effects on anthocyanin synthesis and accumulation. Due to the increasing demand of consumers for healthier foods with high nutraceutical values, this review tries to fill the gap between anthocyanin content and biostimulant application. Here, we elucidate the chemical structure, biosynthetic pathway, plant distribution, and physiological role of anthocyanins in plants. Moreover, we discuss the potential implications for human health derived from the consumption of foods rich in these molecules. Finally, we report on literature data concerning the changes in anthocyanin content and profile after the application of biostimulant products on the most common anthocyanin-containing foods.

scholarly journals Regulation of Nuclear Factor-kappaB Function by O-GlcNAcylation in Inflammation and Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Angela Rose Liu ◽  
Parameswaran Ramakrishnan
Keyword(s):  
Cell Proliferation ◽  
Posttranslational Modifications ◽  
Nuclear Factor Kappab ◽  
Nuclear Factor ◽  
Cancer Cell Proliferation ◽  
The Past ◽  
Pathological Conditions ◽  
Evolutionarily Conserved ◽  
Made In

Nuclear factor-kappaB (NF-κB) is a pleiotropic, evolutionarily conserved transcription factor family that plays a central role in regulating immune responses, inflammation, cell survival, and apoptosis. Great strides have been made in the past three decades to understand the role of NF-κB in physiological and pathological conditions. Carcinogenesis is associated with constitutive activation of NF-κB that promotes tumor cell proliferation, angiogenesis, and apoptosis evasion. NF-κB is ubiquitously expressed, however, its activity is under tight regulation by inhibitors of the pathway and through multiple posttranslational modifications. O-GlcNAcylation is a dynamic posttranslational modification that controls NF-κB-dependent transactivation. O-GlcNAcylation acts as a nutrient-dependent rheostat of cellular signaling. Increased uptake of glucose and glutamine by cancer cells enhances NF-κB O-GlcNAcylation. Growing evidence indicates that O-GlcNAcylation of NF-κB is a key molecular mechanism that regulates cancer cell proliferation, survival and metastasis and acts as link between inflammation and cancer. In this review, we are attempting to summarize the current understanding of the cohesive role of NF-κB O-GlcNAcylation in inflammation and cancer.

scholarly journals Transdifferentiation Meets Next-generation Biotechnologies

StemJournal ◽  
2022 ◽  
pp. 1-11
Author(s):  
Xiaoshan Ke ◽  
Abhimanyu Thakur ◽  
Huanhuan Joyce Chen
Keyword(s):  
Tissue Regeneration ◽  
Disease Modeling ◽  
Directed Differentiation ◽  
Next Generation ◽  
Cell Type ◽  
Promising Alternative ◽  
Cell Lineages ◽  
The Past ◽  
Differentiated Cells ◽  
Cell Sources

Transdifferentiation is the process of converting terminally differentiated cells to another cell type. Being less time-consuming and free from tumorigenesis, it is a promising alternative to directed differentiation, which provides cell sources for tissue regeneration therapy and disease modeling. In the past decades, transdifferentiation was found to happen within or across the cell lineages, being induced by overexpression of key transcription factors, chemical cocktail treatments, etc. Implementing next-generation biotechnologies, such as genome editing tools and scRNA-seq, improves current protocols and has the potential to facilitate discovery in new pathways of transdifferentiation, which will accelerate its application in clinical use.

scholarly journals Velocity of cytoplasm streaming in basal and subbasal cells of antheridium as well as internodal cells of pleuridium in Chara vulgaris L. and GA3 influence on it: videomicroscopic observations

2014 ◽  
Vol 71 (4) ◽  
pp. 283-286
Author(s):  
Maria Kwiatkowska ◽  
Sławomir Malinowski ◽  
Katarzyna Popłońska ◽  
Sławomira Knake ◽  
Anna Sobala
Keyword(s):  
Developmental Stage ◽  
Basal Cell ◽  
Cell Type ◽  
Chara Vulgaris ◽  
Exogenous Gibberellin ◽  
A Cell

The velocity of cytoplasm streaming in an antheridial basal cell and in a subbasal cell as well as in internodal cells of pleuridia carrying antheridia were measured with the use of videomicroscopy. Velocity of streaming proved different depending on a cell type. The most intensive streaming (ca 40 µm/s) was observed in a subbasal cell while in a basal cell it was quite intensive during antheridial filament cells proliferation but falling to half of it during spermatozoid differentiation (ca 20 µm/s and 10 µm/s respectively). In internodal cells of pleuridia the velocity was ca 17 µm/s. GA<sub>3</sub> at the 10<sup>-5</sup>M concentration decreased the velocity of streaming in a basal cell during proliferation of antheridial filament cells and increased it during spermiogenesis. In internodal cells of pleuridia the velocity diminished while in a subbasal cell it rose a little after GA<sub>3</sub> administering. The obtained data suggest that cytoplasm streaming and its reaction to exogenous gibberellin depend on the role of a cell in a multicellulate system; it also depends on a developmental stage.

N-glycans as apical targeting signals in polarized epithelial cells.

2005 ◽  
Vol 72 ◽  
pp. 39-45 ◽  
Author(s):  
Paula Urquhart ◽  
Susan Pang ◽  
Nigel M. Hooper
Keyword(s):  
Epithelial Cells ◽  
Kidney Cells ◽  
Apical Surface ◽  
Madin Darby Canine Kidney ◽  
Targeting Signals ◽  
Polarized Epithelial Cells ◽  
Apical Sorting ◽  
Darby Canine Kidney ◽  
Canine Kidney

MDCK (Madin-Darby canine kidney) cells represent a good model of polarized epithelium to investigate the signals involved in the apical targeting of proteins. As reported previously, GPI (glycosylphosphatidylinositol) anchors mediate the apical sorting of proteins in polarized epithelial cells through their interaction with lipid rafts. However, using a naturally N-glycosylated and GPI-anchored protein, we found that the GPI anchor does not influence the targeting of the protein. It is, in fact, the N-glycans that signal the protein to the apical surface. In the present review, the role of N-glycans and GPI anchors as apical signals is discussed along with the putative mechanisms involved.

scholarly journals Genetic Evidence that GTP Is Required for Transposition of IS903 and Tn552 in Escherichia coli

2005 ◽  
Vol 187 (13) ◽  
pp. 4598-4606 ◽  
Author(s):  
Abbie M. Coros ◽  
Erin Twiss ◽  
Norma P. Tavakoli ◽  
Keith M. Derbyshire
Keyword(s):  
Escherichia Coli ◽  
Developmental Stage ◽  
Biosynthetic Pathway ◽  
Spatial Location ◽  
Colony Growth ◽  
Host Factors ◽  
Mutant Library ◽  
E Coli ◽  
Late Stages

ABSTRACT Surprisingly little is known about the role of host factors in regulating transposition, despite the potentially deleterious rearrangements caused by the movement of transposons. An extensive mutant screen was therefore conducted to identify Escherichia coli host factors that regulate transposition. An E. coli mutant library was screened using a papillation assay that allows detection of IS903 transposition events by the formation of blue papillae on a colony. Several host mutants were identified that exhibited a unique papillation pattern: a predominant ring of papillae just inside the edge of the colony, implying that transposition was triggered within these cells based on their spatial location within the colony. These mutants were found to be in pur genes, whose products are involved in the purine biosynthetic pathway. The transposition ring phenotype was also observed with Tn552, but not Tn10, establishing that this was not unique to IS903 and that it was not an artifact of the assay. Further genetic analyses of purine biosynthetic mutants indicated that the ring of transposition was consistent with a GTP requirement for IS903 and Tn552 transposition. Together, our observations suggest that transposition occurs during late stages of colony growth and that transposition occurs inside the colony edge in response to both a gradient of exogenous purines across the colony and the developmental stage of the cells.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

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