scholarly journals Identifying Common Features in the Activation of Melanocortin-2 Receptors: Studies on the Xenopus tropicalis Melanocortin-2 Receptor

2019 ◽  
Vol 20 (17) ◽  
pp. 4166
Author(s):  
Perry E. Davis ◽  
Emily C. Wilkinson ◽  
Robert M. Dores

The interaction between the pituitary hormone, adrenocorticotropin (ACTH), and melanocortin-2 receptor (MC2R) orthologs involves the H6 F7 R8 W9 and R/K15 K16 R17 R18 motifs in ACTH making contact with corresponding contact sites on MC2R. Earlier studies have localized the common HFRW binding site of all melanocortin receptors to residues in TM2, TM3, and TM6 that are located close to the extracellular space. The current study has identified residues in Xenopus tropicalis (xt) MC2R in TM4 (I158, F161), in EC2 (M166), and in TM5 (V172) that also are involved in activation of xtMC2R, and may be in the R/KKRR contact site of xtMC2R. These results are compared to earlier studies on the corresponding domains of human MC2R and rainbow trout MC2R in an effort to identify common features in the activation of teleost and tetrapod MC2R orthologs following stimulation with ACTH.

Author(s):  
Graeme D. Ruxton ◽  
William L. Allen ◽  
Thomas N. Sherratt ◽  
Michael P. Speed

Aposematism is the pairing of two kinds of defensive phenotype: an often repellent secondary defence that typically renders prey unprofitable to predators if they attack them and some evolved signal that indicates the presence of that defence. Aposematic signals often work to modify the behaviours of predators both before and during attacks. Warning coloration, for example, may increase wariness and hence improve the chances that a chemically defended prey is released unharmed after an attack. An aposematic signal may therefore first tend to reduce the probability that a predator commences attack (a primary defence) and then (as a component of secondary defence) reduce the probability that the prey is injured or killed during any subsequent attack. In this chapter we will consider both the primary and the secondary effects of aposematic signals on prey protection. We begin first by describing the common features of aposematic signals and attempting to show the wide use to which aposematic signalling is deployed across animals (and perhaps plants too). We then review the interesting evolutionary issues aposematic signals raise, including their initial evolution and their integration with sexual and other signals. We also discuss important ecological, co-evolutionary, and macroevolutionary consequences of aposematism.


2021 ◽  
Vol 5 (1) ◽  
pp. 43-51
Author(s):  
Jeong-A Jo

This study aims to examine the common features and differences in how the Chinese-character classifier ‘ ben 本’ is used in Chinese, Korean, and Japanese, and will explore the factors that have affected the categorization processes and patterns of the classifier ‘ ben 本.’ Consideration of the differences in the patterns of usage and categorization of the same Chinese classifier in different languages enables us to look into the perception of the world and the socio cultural differences inherent in each language, the differences in the perception of Chinese characters, and the relationship between classifiers.


2020 ◽  
Vol 401 (6-7) ◽  
pp. 793-809
Author(s):  
Naama Zung ◽  
Maya Schuldiner

AbstractContact sites, areas where two organelles are held in close proximity through the action of molecular tethers, enable non-vesicular communication between compartments. Mitochondria have been center stage in the contact site field since the discovery of the first contact between mitochondria and the endoplasmic reticulum (ER) over 60 years ago. However, only now, in the last decade, has there been a burst of discoveries regarding contact site biology in general and mitochondrial contacts specifically. The number and types of characterized contacts increased dramatically, new molecular mechanisms enabling contact formation were discovered, additional unexpected functions for contacts were shown, and their roles in cellular and organismal physiology were emphasized. Here, we focus on mitochondria as we highlight the most recent developments, future goals and unresolved questions in the field.


Author(s):  
Kelly Cline ◽  
Holly Zullo ◽  
David A Huckaby

Abstract Common student errors and misconceptions can be addressed through the method of classroom voting, in which the instructor presents a multiple-choice question to the class, and after a few minutes for consideration and small-group discussion, each student votes on the correct answer, using a clicker or a phone. If a large number of students have voted for one particular incorrect answer, the instructor can recognize and address the issue. In order to identify multiple-choice questions that are especially effective at provoking common errors and misconceptions, we recorded the percentages of students voting for each option on each question used in 25 sections of integral calculus, taught by 7 instructors, at 4 institutions, over the course of 12 years, on a collection of 172 questions. We restricted our analysis to the 115 questions which were voted on by at least 5 different classes. We present the six questions that caused the largest percentages of students to vote for a particular incorrect answer, discuss how we used these questions in the classroom, and examine the common features of these questions. Further, we look for correlations between question characteristics and the mean percentage of students voting for common errors on these questions, and we find that questions based on general cases have higher percentages of students voting for common errors.


2014 ◽  
Vol 70 (8) ◽  
pp. 58-61
Author(s):  
Aina Mardia Akhmad Aznan ◽  
Zanariah Abdullah ◽  
Vannajan Sanghiran Lee ◽  
Edward R. T. Tiekink

The title compound, C12H11N3O2, is a second monoclinic polymorph (P21, withZ′ = 4) of the previously reported monoclinic (P21/c, withZ′ = 2) form [Akhmad Aznanet al.(2010).Acta Cryst.E66, o2400]. Four independent molecules comprise the asymmetric unit, which have the common features of asyndisposition of the pyridine N atom and the toluene ring, and an intramolecular amine–nitro N—H...O hydrogen bond. The differences between molecules relate to the dihedral angles between the rings which range from 2.92 (19) to 26.24 (19)°. The geometry-optimized structure [B3LYP level of theory and 6–311 g+(d,p) basis set] has the same features except that the entire molecule is planar. In the crystal, the three-dimensional architecture is consolidated by a combination of C—H...O, C—H...π, nitro-N—O...π and π–π interactions [inter-centroid distances = 3.649 (2)–3.916 (2) Å].


2021 ◽  
pp. 251385022098177
Author(s):  
Jeong-A Jo

This study aims to examine the common features and differences in how the Chinese-character classifier ‘ ben 本’ is used in Chinese, Korean, and Japanese, and will explore the factors that have affected the categorization processes and patterns of the classifier ‘ ben 本.’ Consideration of the differences in the patterns of usage and categorization of the same Chinese classifier in different languages enables us to look into the perception of the world and the socio cultural differences inherent in each language, the differences in the perception of Chinese characters, and the relationship between classifiers.


1952 ◽  
Vol 98 (413) ◽  
pp. 515-564 ◽  
Author(s):  
P. M. Yap

Few mental diseases have attracted the attention of medical men working in outlandish parts of the world more than Latah. This is due, not only to its intrinsic interest, showing as it regularly does the unusual symptoms of echolalia, echopraxia, and automatic obedience, but also to its remarkable geographical distribution. This illness was described by travellers to the Malay Archipelago in the latter part of the nineteenth century, but very similar reactions were later found to exist in other lands, known to the native peoples by other names. The term “Latah,” however, is the best known, and as the common features between these various reactions became apparent, it has been used as an inclusive name for them all. It is to-day employed with much the same connotation in the French, Dutch, Italian, and English literature, but the discussion of its nature betrays inadequate understanding, attempts at its nosological classification remain unsatisfactory, and speculations as to its aetology continue to be somewhat fanciful.


Sign in / Sign up

Export Citation Format

Share Document