scholarly journals A structure of human Scap bound to Insig-2 suggests how their interaction is regulated by sterols

Science ◽  
2021 ◽  
pp. eabb2224
Author(s):  
Renhong Yan ◽  
Pingping Cao ◽  
Wenqi Song ◽  
Hongwu Qian ◽  
Ximing Du ◽  
...  
Keyword(s):  
Cellular Homeostasis ◽  
Key Players ◽  
S4 Segment

The SREBP pathway controls cellular homeostasis of sterols. The key players in this pathway, Scap and Insig-1/2, are membrane-embedded sterol sensors. 25-hydroxycholesterol (25HC)-dependent association of Scap and Insigs acts as the master switch for the SREBP pathway. Here, we present cryo-EM analysis of the human Scap and Insig-2 complex in the presence of 25HC, with the transmembrane (TM) domains determined at an average resolution of 3.7 Å. The sterol sensing domain (SSD) in Scap and all six TMs in Insig-2 were resolved. A 25HC molecule is sandwiched between the S4-S6 segments in Scap and TMs 3/4 in Insig-2 in the luminal leaflet of the membrane. Unwinding of the middle of the Scap-S4 segment is crucial for 25HC binding and Insig association.

Mitochondrial hyperfusion: a friend or a foe

2020 ◽  
Vol 48 (2) ◽  
pp. 631-644 ◽  
Author(s):  
Rajdeep Das ◽  
Oishee Chakrabarti
Keyword(s):  
Negative Impact ◽  
Cellular Stress ◽  
Cellular Homeostasis ◽  
Mitochondrial Population

The cellular mitochondrial population undergoes repeated cycles of fission and fusion to maintain its integrity, as well as overall cellular homeostasis. While equilibrium usually exists between the fission–fusion dynamics, their rates are influenced by organellar and cellular metabolic and pathogenic conditions. Under conditions of cellular stress, there is a disruption of this fission and fusion balance and mitochondria undergo either increased fusion, forming a hyperfused meshwork or excessive fission to counteract stress and remove damaged mitochondria via mitophagy. While some previous reports suggest that hyperfusion is initiated to ameliorate cellular stress, recent studies show its negative impact on cellular health in disease conditions. The exact mechanism of mitochondrial hyperfusion and its role in maintaining cellular health and homeostasis, however, remain unclear. In this review, we aim to highlight the different aspects of mitochondrial hyperfusion in either promoting or mitigating stress and also its role in immunity and diseases.

Youth Development in Europe

2009 ◽  
Vol 14 (4) ◽  
pp. 372-375 ◽  
Author(s):  
Katariina Salmela-Aro ◽  
Ingrid Schoon
Keyword(s):  
Young People ◽  
Relationship Quality ◽  
Youth Development ◽  
Social Relationships ◽  
Transition To Adulthood ◽  
Cultural Context ◽  
Integrative Framework ◽  
Reciprocal Interactions ◽  
The Family ◽  
Key Players

A series of six papers on “Youth Development in Europe: Transitions and Identities” has now been published in the European Psychologist throughout 2008 and 2009. The papers aim to make a conceptual contribution to the increasingly important area of productive youth development by focusing on variations and changes in the transition to adulthood and emerging identities. The papers address different aspects of an integrative framework for the study of reciprocal multiple person-environment interactions shaping the pathways to adulthood in the contexts of the family, the school, and social relationships with peers and significant others. Interactions between these key players are shaped by their embeddedness in varied neighborhoods and communities, institutional regulations, and social policies, which in turn are influenced by the wider sociohistorical and cultural context. Young people are active agents, and their development is shaped through reciprocal interactions with these contexts; thus, the developing individual both influences and is influenced by those contexts. Relationship quality and engagement in interactions appears to be a fruitful avenue for a better understanding of how young people adjust to and tackle development to productive adulthood.

Downregulation of Hemeoxygenase-1 and Altered Cellular Homeostasis in Cystic Fibrosis

Pneumologie ◽  
2014 ◽  
Vol 68 (06) ◽  
Author(s):  
SP Chillappagari ◽  
S Venkatesan ◽  
V Garapati ◽  
P Mahavadi ◽  
A Munder ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Cellular Homeostasis

Biological Activity of Trans-Membrane Anion Carriers

2018 ◽  
Vol 25 (30) ◽  
pp. 3560-3576 ◽  
Author(s):  
Massimo Tosolini ◽  
Paolo Pengo ◽  
Paolo Tecilla
Keyword(s):  
Biological Activity ◽  
Membrane Transport ◽  
Anticancer Agents ◽  
Biological Effects ◽  
Structure Activity Relationship ◽  
New Drugs ◽  
Activity Relationship ◽  
Anion Channels ◽  
Cellular Homeostasis ◽  
Structure Activity

Natural and synthetic anionophores promote the trans-membrane transport of anions such as chloride and bicarbonate. This process may alter cellular homeostasis with possible effects on internal ions concentration and pH levels triggering several and diverse biological effects. In this article, an overview of the recent results on the study of aniontransporters, mainly acting with a carrier-type mechanism, is given with emphasis on the structure/activity relationship and on their biological activity as antibiotic and anticancer agents and in the development of new drugs for treating conditions derived from dysregulation of natural anion channels.

The Sino–Russian Strategic Partnership

2018 ◽  
Author(s):  
Paul J. Bolt ◽  
Sharyl N. Cross
Keyword(s):  
The United States ◽  
Strategic Partnership ◽  
Relative Power ◽  
Mutual Respect ◽  
Major Power ◽  
The West ◽  
The World ◽  
Key Players ◽  
Common Interests ◽  
The Relationship

The Conclusion reviews the volume’s major themes. Russia and China have common interests that cement their partnership, and are key players in shaping the international order. Both seek better relations with the West, but on the basis of “mutual respect” and “equality.” While the relationship has grown deeper, particularly since 2014, China and Russia are partners but not allies. Thus, their relationship is marked by burgeoning cooperation, but still areas of potential competition and friction. Russia in particular must deal with China’s growing relative power at the same time that it is isolated from the West. While the Russian–Chinese relationship creates challenges for the United States and Europe and a return of major power rivalry, there is also room for cooperation in the strategic triangle comprising China, Russia, and the West. Looking ahead, the world is in a period of dramatic transition.

scholarly journals Understanding sex differences in long-term blood pressure regulation: insights from experimental studies and computational modeling

2019 ◽  
Vol 316 (5) ◽  
pp. H1113-H1123 ◽  
Author(s):  
Sameed Ahmed ◽  
Rui Hu ◽  
Jessica Leete ◽  
Anita T. Layton
Keyword(s):  
Blood Pressure ◽  
Sex Differences ◽  
Computational Models ◽  
Experimental Studies ◽  
Pressure Control ◽  
Blood Pressure Regulation ◽  
Pressure Regulation ◽  
Physiological Processes ◽  
Key Players

Sex differences in blood pressure and the prevalence of hypertension are found in humans and animal models. Moreover, there has been a recent explosion of data concerning sex differences in nitric oxide, the renin-angiotensin-aldosterone system, inflammation, and kidney function. These data have the potential to reveal the mechanisms underlying male-female differences in blood pressure control. To elucidate the interactions among the multitude of physiological processes involved, one may apply computational models. In this review, we describe published computational models that represent key players in blood pressure regulation, and highlight sex-specific models and their findings.

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