scholarly journals The Specification and Function of Enteroendocrine Cells in Drosophila and Mammals: A Comparative Review

FEBS Journal ◽  
2021 ◽  
Author(s):  
Xingting Guo ◽  
Jiaying Lv ◽  
Rongwen Xi
Keyword(s):  
Enteroendocrine Cells ◽  
Comparative Review ◽  
And Function

scholarly journals A Comparative Review on the Catalytic Mechanism of Nonheme Iron Hydroxylases and Halogenases

Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 314 ◽  
Author(s):  
Amy Timmins ◽  
Sam P. de Visser
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Oxygen ◽  
Catalytic Mechanism ◽  
Computational Modelling ◽  
Active Species ◽  
Nonheme Iron ◽  
Comparative Review ◽  
Modelling Studies ◽  
Iron Heme ◽  
And Function

Enzymatic halogenation and haloperoxidation are unusual processes in biology; however, a range of halogenases and haloperoxidases exist that are able to transfer an aliphatic or aromatic C–H bond into C–Cl/C–Br. Haloperoxidases utilize hydrogen peroxide, and in a reaction with halides (Cl−/Br−), they react to form hypohalides (OCl−/OBr−) that subsequently react with substrate by halide transfer. There are three types of haloperoxidases, namely the iron-heme, nonheme vanadium, and flavin-dependent haloperoxidases that are reviewed here. In addition, there are the nonheme iron halogenases that show structural and functional similarity to the nonheme iron hydroxylases and form an iron(IV)-oxo active species from a reaction of molecular oxygen with α-ketoglutarate on an iron(II) center. They subsequently transfer a halide (Cl−/Br−) to an aliphatic C–H bond. We review the mechanism and function of nonheme iron halogenases and hydroxylases and show recent computational modelling studies of our group on the hectochlorin biosynthesis enzyme and prolyl-4-hydroxylase as examples of nonheme iron halogenases and hydroxylases. These studies have established the catalytic mechanism of these enzymes and show the importance of substrate and oxidant positioning on the stereo-, chemo- and regioselectivity of the reaction that takes place.

scholarly journals Pulmonary Smooth Muscle in Vertebrates: A Comparative Review of Structure and Function

2019 ◽  
Vol 59 (1) ◽  
pp. 10-28 ◽  
Author(s):  
Robert L Cieri
Keyword(s):  
Smooth Muscle ◽  
Cholinergic Innervation ◽  
Lung Structure ◽  
Airway Caliber ◽  
Comparative Review ◽  
Species Specific ◽  
Shape Complexity ◽  
Visceral Smooth Muscle ◽  
And Function ◽  
Tension Regulation

Abstract Although the airways of vertebrates are diverse in shape, complexity, and function, they all contain visceral smooth muscle. The morphology, function, and innervation of this tissue in airways is reviewed in actinopterygians, lungfish, amphibians, non-avian reptiles, birds, and mammals. Smooth muscle was likely involved in tension regulation ancestrally, and may serve to assist lung emptying in fishes and aquatic amphibians, as well as maintain internal lung structure. In certain non-avian reptiles and anurans antagonistic smooth muscle fibers may contribute to intrapulmonary gas mixing. In mammals and birds, smooth muscle regulates airway caliber, and may be important in controlling the distribution of ventilation at rest and exercise, or during thermoregulatory and vocal hyperventilation. Airway smooth muscle is controlled by the autonomic nervous system: cranial cholinergic innervation generally causes excitation, cranial non-adrenergic, non-cholinergic innervation causes inhibition, and spinal adrenergic (SA) input causes species-specific, often heterogeneous contractions and relaxations.

scholarly journals Induction of different human enteroendocrine cells in intestinal organoids

2020 ◽  
Author(s):  
Hans Clevers ◽  
Joep Beumer
Keyword(s):  
Cell Types ◽  
Bmp Signaling ◽  
Enteroendocrine Cells ◽  
Model Systems ◽  
Endocrine Organ ◽  
Intestinal Organoids ◽  
Novel Approach ◽  
Key Players ◽  
And Function ◽  
Diabetes And Obesity

Abstract Intestinal enteroendocrine cells \(EECs) are key players in mammalian physiology as largest endocrine organ, and regulate metabolic processes such as insulin secretion and induction of satiety. EECs are rare cell types \(less than 1% of the epithelium) and produce a large number of different hormones making these challenging to study. Model systems to assess the differentiation and function of these essential cell types have been lacking. In a novel approach, we describe the induction of human EECs in intestinal organoids. Moreover, in the manuscript linked to this protocol, we describe that manipulating the BMP signaling pathway allows to induce expression of specific sets of hormones that correspond to the EEC state in the crypt-villus axis. This differentiation platform can be used to study the function of EECs and could contribute to the development of drugs for diabetes and obesity.

Calf muscle architecture and function in ultra runners and low physical activity individuals: A comparative review

2018 ◽  
Vol 1 (6) ◽  
pp. 250-256
Author(s):  
Kim A. Buchholtz ◽  
Michael I. Lambert ◽  
Andrew Bosch ◽  
Theresa L. Burgess
Keyword(s):  
Physical Activity ◽  
Muscle Architecture ◽  
Calf Muscle ◽  
Comparative Review ◽  
And Function

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

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