scholarly journals Three Decades of Advances in Arabinogalactan-Protein Biosynthesis

2020 ◽  
Vol 11 ◽  
Author(s):  
Jessy Silva ◽  
Ricardo Ferraz ◽  
Paul Dupree ◽  
Allan M. Showalter ◽  
Sílvia Coimbra
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Protein Biosynthesis ◽  
Arabinogalactan Protein ◽  
The Past ◽  
Outer Leaflet ◽  
The Family ◽  
Development Processes ◽  
Proline Hydroxylation ◽  
Genetics And Genomics

Arabinogalactan-proteins (AGPs) are a large, complex, and highly diverse class of heavily glycosylated proteins that belong to the family of cell wall hydroxyproline-rich glycoproteins. Approximately 90% of the molecules consist of arabinogalactan polysaccharides, which are composed of arabinose and galactose as major sugars and minor sugars such as glucuronic acid, fucose, and rhamnose. About half of the AGP family members contain a glycosylphosphatidylinositol (GPI) lipid anchor, which allows for an association with the outer leaflet of the plasma membrane. The mysterious AGP family has captivated the attention of plant biologists for several decades. This diverse family of glycoproteins is widely distributed in the plant kingdom, including many algae, where they play fundamental roles in growth and development processes. The journey of AGP biosynthesis begins with the assembly of amino acids into peptide chains of proteins. An N-terminal signal peptide directs AGPs toward the endoplasmic reticulum, where proline hydroxylation occurs and a GPI anchor may be added. GPI-anchored AGPs, as well as unanchored AGPs, are then transferred to the Golgi apparatus, where extensive glycosylation occurs by the action of a variety glycosyltransferase enzymes. Following glycosylation, AGPs are transported by secretory vesicles to the cell wall or to the extracellular face of the plasma membrane (in the case of GPI-anchored AGPs). GPI-anchored proteins can be released from the plasma membrane into the cell wall by phospholipases. In this review, we present an overview of the accumulated knowledge on AGP biosynthesis over the past three decades. Particular emphasis is placed on the glycosylation of AGPs as the sugar moiety is essential to their function. Recent genetics and genomics approaches have significantly contributed to a broader knowledge of AGP biosynthesis. However, many questions remain to be elucidated in the decades ahead.

scholarly journals Fasciclin-Like Arabinogalactan-Protein 16 (FLA16) Is Required for Stem Development in Arabidopsis

2020 ◽  
Vol 11 ◽  
Author(s):  
Edgar Liu ◽  
Colleen P. MacMillan ◽  
Thomas Shafee ◽  
Yingxuan Ma ◽  
Julian Ratcliffe ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Biomechanical Properties ◽  
Arabinogalactan Protein ◽  
Stem Length ◽  
Group A ◽  
Stem Development ◽  
Secondary Cell Wall Synthesis ◽  
Group B ◽  
And Function

The predominant Fascilin 1 (FAS1)-containing proteins in plants belong to the Fasciclin-Like Arabinogalactan-protein (FLA) family of extracellular glycoproteins. In addition to FAS1 domains, these multi-domain FLA proteins contain glycomotif regions predicted to direct addition of large arabinogalactan (AG) glycans and many contain signal sequences for addition of a glycosylphosphatidylinositol (GPI)-anchor to tether them to the plasma membrane. FLAs are proposed to play both structural and signaling functions by forming a range of interactions in the plant extracellular matrix, similar to FAS1-containing proteins in animals. FLA group B members contain two FAS1 domains and are not predicted to be GPI-anchored. None of the group B members have been functionally characterized or their sub-cellular location resolved, limiting understanding of their function. We investigated the group B FLA16 in Arabidopsis that is predominantly expressed in inflorescence tissues. FLA16 is the most highly expressed FLA in the stem after Group A members FLA11 and FLA12 that are stem specific. A FLA16-YFP fusion protein driven by the endogenous putative FLA16 promoter in wild type background showed expression in cells with secondary cell walls, and FLA16 displayed characteristics of cell wall glycoproteins with moderate glycosylation. Investigation of a fla16 mutant showed loss of FLA16 leads to reduced stem length and altered biomechanical properties, likely as a result of reduced levels of cellulose. Immuno-labeling indicated support for FLA16 location to the plasma-membrane and (apoplastic) cell wall of interfascicular stem fiber cells. Together these results indicate FLA16, a two-FAS1 domain FLAs, plays a role in plant secondary cell wall synthesis and function.

scholarly journals The Role of the Primary Cell Wall in Plant Morphogenesis

2018 ◽  
Vol 19 (9) ◽  
pp. 2674 ◽  
Author(s):  
Derek Lamport ◽  
Li Tan ◽  
Michael Held ◽  
Marcia Kieliszewski
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Computational Modelling ◽  
Primary Cell ◽  
Arabinogalactan Protein ◽  
Primary Cell Wall ◽  
Proton Pumps ◽  
Plant Morphogenesis ◽  
Evolutionary Origins

Morphogenesis remains a riddle, wrapped in a mystery, inside an enigma. It remains a formidable problem viewed from many different perspectives of morphology, genetics, and computational modelling. We propose a biochemical reductionist approach that shows how both internal and external physical forces contribute to plant morphogenesis via mechanical stress–strain transduction from the primary cell wall tethered to the plasma membrane by a specific arabinogalactan protein (AGP). The resulting stress vector, with direction defined by Hechtian adhesion sites, has a magnitude of a few piconewtons amplified by a hypothetical Hechtian growth oscillator. This paradigm shift involves stress-activated plasma membrane Ca2+ channels and auxin-activated H+-ATPase. The proton pump dissociates periplasmic AGP-glycomodules that bind Ca2+. Thus, as the immediate source of cytosolic Ca2+, an AGP-Ca2+ capacitor directs the vectorial exocytosis of cell wall precursors and auxin efflux (PIN) proteins. In toto, these components comprise the Hechtian oscillator and also the gravisensor. Thus, interdependent auxin and Ca2+ morphogen gradients account for the predominance of AGPs. The size and location of a cell surface AGP-Ca2+ capacitor is essential to differentiation and explains AGP correlation with all stages of morphogenetic patterning from embryogenesis to root and shoot. Finally, the evolutionary origins of the Hechtian oscillator in the unicellular Chlorophycean algae reflect the ubiquitous role of chemiosmotic proton pumps that preceded DNA at the dawn of life.

scholarly journals The Role of the Primary Cell Wall in Plant Morphogenesis

2018 ◽  
Author(s):  
Derek T Lamport ◽  
Li Tan ◽  
Michael Held ◽  
Marcia J. Kieliszewski
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Computational Modelling ◽  
Primary Cell ◽  
Arabinogalactan Protein ◽  
Primary Cell Wall ◽  
Proton Pumps ◽  
Plant Morphogenesis ◽  
Evolutionary Origins

Morphogenesis remains a riddle, wrapped in a mystery, inside an enigma. It remains a formidable problem viewed from many different perspectives of morphology, genetics, and computational modelling. We propose a biochemical reductionist approach that shows how both internal and external physical forces contribute to plant morphogenesis via mechanical stress-strain transduction from the primary cell wall tethered to the plasma membrane by a specific arabinogalactan protein (AGP). The resulting stress vector with direction defined by Hechtian adhesion sites, has a magnitude of a few picoNewtons amplified by a hypothetical Hechtian growth oscillator. This paradigm shift involves stress activated plasma membrane Ca2+channels and auxin-activated H+-ATPase. The proton pump dissociates periplasmic AGP-glycomodules that bind Ca2+. Thus, as the immediate source of cytosolic Ca2+ an AGP-Ca2+ capacitor directs vectorial exocytosis of cell wall precursors and auxin efflux (PIN) proteins. In toto these components comprise the Hechtian Oscillator and also the gravisensor. Thus interdependent auxin and Ca2+ morphogen gradients account for the predominance of AGPs. The size and location of a cell surface AGP-Ca2+ capacitor is essential to differentiation and explains AGP correlation with all stages of morphogenetic patterning from embryogenesis to root and shoot. Finally, evolutionary origins of the Hechtian Oscillator in the unicellular Chlorophycean algae reflect the ubiquitous role of chemiosmotic proton pumps that preceded DNA at the dawn of life.

Microanatomy of the Periplasm of Bacillus Licheniformis

1971 ◽  
Vol 29 ◽  
pp. 262-263
Author(s):  
B.K. Ghosh
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Bacillus Licheniformis ◽  
External Environment ◽  
Permeability Barrier ◽  
Periplasmic Space ◽  
Modified Technique ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

Enrichment of vitronectin- and fibronectin-like proteins in NaCI-adapted plant cells and evidence for their involvement in plasma membrane-cell wall adhesion

1993 ◽  
Vol 3 (5) ◽  
pp. 637-646 ◽  
Author(s):  
Jian-Kang Zhu ◽  
Jun Shi ◽  
Utpal Singh ◽  
Sarah E. Wyatt ◽  
Ray A. Bressan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells ◽  
Membrane Cell

The Medicinal Chemistry of Therapeutic Peptides: Recent Developments in Synthesis and Design Optimizations

2019 ◽  
Vol 26 (13) ◽  
pp. 2330-2355 ◽  
Author(s):  
Anutthaman Parthasarathy ◽  
Sasikala K. Anandamma ◽  
Karunakaran A. Kalesh
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Therapeutic Potential ◽  
The Past ◽  
Recombinant Production ◽  
Tremendous Progress ◽  
Recent Developments ◽  
Therapeutic Peptides ◽  
Development Processes ◽  
Delivery Strategies

Peptide therapeutics has made tremendous progress in the past decade. Many of the inherent weaknesses of peptides which hampered their development as therapeutics are now more or less effectively tackled with recent scientific and technological advancements in integrated drug discovery settings. These include recent developments in synthetic organic chemistry, high-throughput recombinant production strategies, highresolution analytical methods, high-throughput screening options, ingenious drug delivery strategies and novel formulation preparations. Here, we will briefly describe the key methodologies and strategies used in the therapeutic peptide development processes with selected examples of the most recent developments in the field. The aim of this review is to highlight the viable options a medicinal chemist may consider in order to improve a specific pharmacological property of interest in a peptide lead entity and thereby rationally assess the therapeutic potential this class of molecules possesses while they are traditionally (and incorrectly) considered ‘undruggable’.

An Overview on Phytochemical and Pharmacological Profile of Morus alba Linn.

2020 ◽  
Vol 16 ◽  
Author(s):  
Arpita Paul ◽  
Monami Rajiung ◽  
Kamaruz Zaman ◽  
Sushil Kumar Chaudhary ◽  
Hans Raj Bhat ◽  
...  
Keyword(s):  
Traditional Medicine ◽  
Morus Alba ◽  
Biologically Active ◽  
Pharmacological Profile ◽  
Pharmacological Activities ◽  
Significant Information ◽  
The Past ◽  
Comprehensive Information ◽  
The Family ◽  
White Mulberry

Background: Morus alba Linn. commonly known as white mulberry, belongs to the family Moraceae, is a promising traditional medicine. In Asia, besides its use in the preparation of delicacies, every part of this plant is utilized in traditional medicine. Over the past decade, studies related to identification and isolation of biologically active compounds, with flavonoids as the major class of phytoconstituents, from this plant has been reported. These phytoconstituents are not only found to be beneficial for the maintenance of general health but also are associated with a range of potential pharmacological activities such as antioxidant, anti-inflammatory, anti-diabetic, anticancer, hepatoprotective, cardioprotective, neuroprotective to name a few. Objective: This review aims to provide upgraded and comprehensive information regarding the phytochemical, ethnomedicinal use and pharmacological profile of the plant Morus alba Linn. Method: The significant information has been collected through various database viz. PubMed, Scopus, Web of Science, Science Direct based on the recent findings, using different terms of Morus alba. Results: The outcome of the study suggests that Morus alba is a multifunctional plant numerous phytochemicals, and possess a range of pharmacological activities. Conclusion: The data assembled on Morus alba will be beneficial to trigger research in various fields of pharmaceutical and allied science to explore the medicinal importance of this unique plant.

Factor X Deficiency Due to a Compound Heterozygosis Between a New Mutation (Gla72Asp) in Exon 2 and an Already Known one (Gly154Arg) in Exon 5: Factor X Mar Del Plata1)

2019 ◽  
Vol 19 (2) ◽  
pp. 169-173
Author(s):  
Antonio Girolami ◽  
Diana Noemi Garcia de Paoletti ◽  
Marcelo Leonardo Nenkies ◽  
Silvia Ferrari ◽  
Hugo Guglielmone
Keyword(s):  
Bleeding Tendency ◽  
Bleeding Disorders ◽  
Factor X ◽  
Substitution Therapy ◽  
New Mutation ◽  
Exon 2 ◽  
The Third ◽  
The Past ◽  
Factor X Deficiency ◽  
The Family

Background: Investigation of rare bleeding disorders in Latin-America. Objective: The report of a new case of FX deficiency due to a compound heterozygosis. Methods: Accepted clotting procedures were used. Sequencing of DNA was carried out by means of Applied Biosystems Instruments. Results: A compound heterozygote due to the association of a new mutation (Gla72Asp) with an already known mutation (Gly154Arg) of the FX gene is reported. The proposita is a 38 year old female who had a moderate bleeding tendency (menorrhagia, epistaxis, easy bruising). The proposita has never received substitution therapy but in the occasion of a uterine biopsy. The mother was asymptomatic but was a heterozygote for the new mutation. The father was asymptomatic but had deserted the family and could not be investigated. After this abandonment the mother of the proposita re-married with an asymptomatic man and she gave birth to a son who was asymptomatic but was also heterozygous for the new mutation (Gla72Asp). As a consequence it has to be assumed that the first husband of the mother of the proposita was heterozygous for the known mutation (Gly154Arg). Conclusion: This is the third case of a new mutation in the FX gene reported, during the past few years, in Argentina.

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