scholarly journals The small and large ribosomal subunits depend on each other for stability and accumulation

2019 ◽  
Vol 2 (2) ◽  
pp. e201800150 ◽  
Author(s):  
Brian Gregory ◽  
Nusrat Rahman ◽  
Ananth Bommakanti ◽  
Md Shamsuzzaman ◽  
Mamata Thapa ◽  
...  

The 1:1 balance between the numbers of large and small ribosomal subunits can be disturbed by mutations that inhibit the assembly of only one of the subunits. Here, we have investigated if the cell can counteract an imbalance of the number of the two subunits. We show that abrogating 60S assembly blocks 40S subunit accumulation. In contrast, cessation of the 40S pathways does not prevent 60S accumulation, but does, however, lead to fragmentation of the 25S rRNA in 60S subunits and formation of a 55S ribosomal particle derived from the 60S. We also present evidence suggesting that these events occur post assembly and discuss the possibility that the turnover of subunits is due to vulnerability of free subunits not paired with the other subunit to form 80S ribosomes.

2006 ◽  
Vol 188 (3) ◽  
pp. 1205-1210 ◽  
Author(s):  
A. E. Sikora ◽  
R. Zielke ◽  
K. Datta ◽  
J. R. Maddock

ABSTRACT It was previously reported that unlike the other obg/cgtA GTPases, the Vibrio harveyi cgtAV is not essential. Here we show that cgtAV was not disrupted in these studies and is, in fact, essential for viability. Depletion of CgtAV did not result in cell elongation. CgtAV is associated with the large ribosomal particle. In light of our results, we predict that the V. harveyi CgtAV protein plays a similar essential role to that seen for Obg/CgtA proteins in other bacteria.


2020 ◽  
Vol 14 (1) ◽  
pp. 32-37
Author(s):  
Christian Domingo Ribas

The COVID-19 pandemic is a recently emerging problem. This has caused that the knowledge of the disease has been progressive and, therefore, the therapeutic decisions have been conditioned by this lack of knowledge on the one hand and by the therapeutic limitations on the other. Many published studies are methodologically weak and their conclusions, of limited value, have contributed to creating confusion on the therapeutic approach of the disease. In the present paper, we propose a therapeutic approach based on a new disease staging. The therapeutic approach is divided into two big sections: the pharmacological treatment for the phase of viral replication, cytokine storm or late respiratory events (which includes the adult respiratory distress syndrome (ARDS)) and the treatment of the respiratory failure In every stage, we discuss the pathophysiology and comment (accept or rule out) the pharmacological options according to the present evidence. Moreover, we indicate how respiratory failure should be treated. Some characteristics are based on the evidence found in the literature. Others are the result of my experience in other situations.


1990 ◽  
Vol 265 (2) ◽  
pp. 609-612 ◽  
Author(s):  
L Van Den Bosch ◽  
H De Smedt ◽  
L Missiaen ◽  
J B Parys ◽  
R Borghgraef

We present evidence for the existence of an Na(+)-dependent transporter and an Na(+)-independent transporter for polyamines in LLC-PK1 cells. Both transporters could be discriminated by their sensitivity to inhibitors, particularly rho-chloromercuriphenyl sulphate and various polycationic molecules. By using cell monolayers grown on a permeable filter support, we have found that the Na(+)-dependent polyamine uptake occurred preferentially from the basolateral side. The Na(+)-independent uptake, on the other hand, occurred to the same extent from either the apical or the basolateral side.


2005 ◽  
Vol 38 (6) ◽  
pp. 811-819 ◽  
Author(s):  
ANTHONY F. BOGAERT ◽  
JIAN LIU

Birth order is correlated with male sexual orientation, but the reason(s) for this relationship is unclear. In the present study, data from a Canadian sample of homosexual and heterosexual men (N=604) were used to present evidence of two independent birth order interactions – one with height and the other with parental age – predicting sexual orientation in men. If these findings prove reliable, it raises the possibility that different aetiological factors underlie the birth order/sexual orientation relationship in men.


1970 ◽  
Vol 25 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Wolfram Domschke ◽  
Jürgen G. Meyer-Bertenrath

After preparation of a coloured protein component containing iron from rat liver ribosomes 1 this fraction was submitted to detailed analysis by means of polyacrylamide gel electrophoresis. Thus it may be separated into one main and two secondary bands, which do not contain RNA detectable by methylene blue staining. The ferric content of all bands can be demonstrated by staining with 2,4-dinitroso-1,3-naphthalenediol 2. These bands are to be found in the large ribosomal subunits as well as in the small one in qualitative conformity, they differ, however, in their quantitative relations to each other depending on origin. LiCl-extraction as described for the preparation of ribosomal proteins causes dissociation of the chromoproteid fraction into six bands possessing lower molecular weights each than the original bands.The chromoproteids, localized in the large ribosomal subunits on the one hand and in the small subunits on the other hand were prepared differentiatedly by gel filtration. Results show the chromoproteid represented in the 57-S-subunit on a bigger scale than the nucleoproteid part, on the contrary, the 29-S-subunit is constructed of RNA-containing material preferably.


2019 ◽  
Vol 30 (2) ◽  
pp. 279-292
Author(s):  
Aija Logren ◽  
Johanna Ruusuvuori ◽  
Jaana Laitinen

In this article, we examine comparative time-framed experience telling: episodes of interaction in health promotion group discussions in which one of the participants tells their experience and, in response, another participant tells their own experiences from separate moments or periods of their life and compares them. In so doing, group members reinforce and encourage the previous speaker’s positive stance or challenge the negative stance toward contextually relevant objects: behavior change and suggested solutions. This practice allows group members to demonstrate their independent access to experiences that are similar to those of the other, present evidence of similarities and differences between the experiences, and show their epistemic independence regarding their claims. By recontextualizing the experience of the other in this way, it becomes possible for the group members to interpret and even oppose it while maintaining a level of understanding of the differences between the experiences in question and respecting them.


1990 ◽  
Vol 156 (6) ◽  
pp. 878-882 ◽  
Author(s):  
M. W. P. Carney

Recently, research into the connection between vitamins and psychiatric disorder, particularly affective changes, has been in the doldrums, with the exceptions perhaps of studies of folic acid and pyridoxine. The best way for research to proceed is first to establish that the association of a vitamin deficiency with a psychiatric disorder is beyond a chance finding. Then, questions should be asked about what mental symptoms it is linked with, and what the other associations (malnutrition, drugs, physical illness, etc) are. Lastly, queries should be raised about whether the association is causal or if the mental symptoms are merely secondary to the anorexia and poor diet so common in mental illness (or whether they are linked in a vicious circle as suggested by Reynoldset al(1971)). These questions became pertinent in the mid-1960s when reliable ways of assaying B vitamins such as folic acid became more generally available. In this review, I present evidence that deficiencies of folic acid, B12, thiamine, riboflavin, pyridoxine and ascorbic acid are not infrequently found in psychiatric practice. It should be remembered, however, that some ways of assaying vitamins are liable to give a larger proportion of spurious low results than other methods (false positives), although the adoption of more reliable ways of assaying vitamins should reduce this.


1986 ◽  
Vol 88 (2) ◽  
pp. 237-251 ◽  
Author(s):  
W J Germann ◽  
M E Lowy ◽  
S A Ernst ◽  
D C Dawson

The K conductance of the basolateral membrane of turtle colon was measured in amphotericin-treated cell layers under a variety of ionic conditions. Changing the composition of the bathing solutions changed not only the magnitude but also the physical properties of the basolateral K conductance. The results are consistent with the notion that altered ionic environments can lead to changes in the relative abundance of two different populations of K channels in the basolateral membrane, which can be differentiated on the basis of pharmacological specificity, ion selectivity, and tracer kinetics. In the following article (Germann, W. J., S. A. Ernst, and D. C. Dawson, 1986, Journal of General Physiology, 88:253-274), we present evidence consistent with the hypothesis that one of these conductances was due to the same channels that give rise to the normal resting basolateral K conductance of the transporting cells, while the other was associated with experimental maneuvers that led to extreme swelling of the epithelial cells.


2018 ◽  
Vol 30 (10) ◽  
pp. 1499-1516 ◽  
Author(s):  
Valentinos Zachariou ◽  
Zaid N. Safiullah ◽  
Leslie G. Ungerleider

The fusiform and occipital face areas (FFA and OFA) are functionally defined brain regions in human ventral occipitotemporal cortex associated with face perception. There is an ongoing debate, however, whether these regions are face-specific or whether they also facilitate the perception of nonface object categories. Here, we present evidence that, under certain conditions, bilateral FFA and OFA respond to a nonface category equivalently to faces. In two fMRI sessions, participants performed same–different judgments on two object categories (faces and chairs). In one session, participants differentiated between distinct exemplars of each category, and in the other session, participants differentiated between exemplars that differed only in the shape or spatial configuration of their features (featural/configural differences). During the latter session, the within-category similarity was comparable for both object categories. When differentiating between distinct exemplars of each category, bilateral FFA and OFA responded more strongly to faces than to chairs. In contrast, during featural/configural difference judgments, bilateral FFA and OFA responded equivalently to both object categories. Importantly, during featural/configural difference judgments, the magnitude of activity within FFA and OFA evoked by the chair task predicted the participants' behavioral performance. In contrast, when participants differentiated between distinct chair exemplars, activity within these face regions did not predict the behavioral performance of the chair task. We conclude that, when the within-category similarity of a face and a nonface category is comparable and when the same cognitive strategies used to process a face are applied to a nonface category, the FFA and OFA respond equivalently to that nonface category and faces.


2017 ◽  
Vol 216 (12) ◽  
pp. 4141-4151 ◽  
Author(s):  
Yu Chen ◽  
David C. Gershlick ◽  
Sang Yoon Park ◽  
Juan S. Bonifacino

Biosynthetic sorting of newly synthesized transmembrane cargos to endosomes and lysosomes is thought to occur at the TGN through recognition of sorting signals in the cytosolic tails of the cargos by adaptor proteins, leading to cargo packaging into coated vesicles destined for the endolysosomal system. Here we present evidence for a different mechanism in which two sets of endolysosomal proteins undergo early segregation to distinct domains of the Golgi complex by virtue of the proteins’ luminal and transmembrane domains. Proteins in one Golgi domain exit into predominantly vesicular carriers by interaction of sorting signals with adaptor proteins, but proteins in the other domain exit into predominantly tubular carriers shared with plasma membrane proteins, independently of signal–adaptor interactions. These findings demonstrate that sorting of endolysosomal proteins begins at an earlier stage and involves mechanisms that partly differ from those described by classical models.


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