scholarly journals Cargo Recognition and Function of Selective Autophagy Receptors in Plants

2021 ◽  
Vol 22 (3) ◽  
pp. 1013
Author(s):  
Shuwei Luo ◽  
Xifeng Li ◽  
Yan Zhang ◽  
Yunting Fu ◽  
Baofang Fan ◽  
...  
Keyword(s):  
Cellular Response ◽  
Plant Responses ◽  
Biological Functions ◽  
Biotic And Abiotic Stresses ◽  
Selective Autophagy ◽  
Evolutionarily Conserved ◽  
Autophagic Degradation ◽  
Species Specific ◽  
And Function ◽  
Cellular Components

Autophagy is a major quality control system for degradation of unwanted or damaged cytoplasmic components to promote cellular homeostasis. Although non-selective bulk degradation of cytoplasm by autophagy plays a role during cellular response to nutrient deprivation, the broad roles of autophagy are primarily mediated by selective clearance of specifically targeted components. Selective autophagy relies on cargo receptors that recognize targeted components and recruit them to autophagosomes through interaction with lapidated autophagy-related protein 8 (ATG8) family proteins anchored in the membrane of the forming autophagosomes. In mammals and yeast, a large collection of selective autophagy receptors have been identified that mediate the selective autophagic degradation of organelles, aggregation-prone misfolded proteins and other unwanted or nonnative proteins. A substantial number of selective autophagy receptors have also been identified and functionally characterized in plants. Some of the autophagy receptors in plants are evolutionarily conserved with homologs in other types of organisms, while a majority of them are plant-specific or plant species-specific. Plant selective autophagy receptors mediate autophagic degradation of not only misfolded, nonactive and otherwise unwanted cellular components but also regulatory and signaling factors and play critical roles in plant responses to a broad spectrum of biotic and abiotic stresses. In this review, we summarize the research on selective autophagy in plants, with an emphasis on the cargo recognition and the biological functions of plant selective autophagy receptors.

scholarly journals ATG8-Interacting Motif: Evolution and Function in Selective Autophagy of Targeting Biological Processes

2021 ◽  
Vol 12 ◽  
Author(s):  
Wanqing Liu ◽  
Zinan Liu ◽  
Zulong Mo ◽  
Shaoying Guo ◽  
Yunfeng Liu ◽  
...  
Keyword(s):  
Dual Role ◽  
Current Understanding ◽  
Biological Processes ◽  
Docking Site ◽  
Selective Autophagy ◽  
Evolutionarily Conserved ◽  
And Function ◽  
Cellular Components

Autophagy is an evolutionarily conserved vacuolar process functioning in the degradation of cellular components for reuse. In plants, autophagy is generally activated upon stress and its regulation is executed by numbers of AuTophaGy-related genes (ATGs), of which the ATG8 plays a dual role in both biogenesis of autophagosomes and recruitment of ATG8-interacting motif (AIM) anchored selective autophagy receptors (SARs). Such motif is either termed as AIM or ubiquitin-interacting motif (UIM), corresponding to the LC3-interacting region (LIR)/AIM docking site (LDS) or the UIM docking site (UDS) of ATG8, respectively. To date, dozens of AIM or UIM containing SARs have been characterized. However, the knowledge of these motifs is still obscured. In this review, we intend to summarize the current understanding of SAR proteins and discuss the conservation and diversification of the AIMs/UIMs, expectantly providing new insights into the evolution of them in various biological processes in plants.

scholarly journals A Decade of Mighty Lipophagy: What We Know and What Facts We Need to Know?

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Muhammad Babar Khawar ◽  
Muddasir Hassan Abbasi ◽  
Mussarat Rafiq ◽  
Naila Naz ◽  
Rabia Mehmood ◽  
...  
Keyword(s):  
Cell Death ◽  
Lipid Droplets ◽  
Lysosomal Enzymes ◽  
Lipid Homeostasis ◽  
Cellular Lipid ◽  
Biological Functions ◽  
Lysosomal Function ◽  
Selective Autophagy ◽  
Cellular Components ◽  
Different Levels

Lipids are integral cellular components that act as substrates for energy provision, signaling molecules, and essential constituents of biological membranes along with a variety of other biological functions. Despite their significance, lipid accumulation may result in lipotoxicity, impair autophagy, and lysosomal function that may lead to certain diseases and metabolic syndromes like obesity and even cell death. Therefore, these lipids are continuously recycled and redistributed by the process of selective autophagy specifically termed as lipophagy. This selective form of autophagy employs lysosomes for the maintenance of cellular lipid homeostasis. In this review, we have reviewed the current literature about how lipid droplets (LDs) are recruited towards lysosomes, cross-talk between a variety of autophagy receptors present on LD surface and lysosomes, and lipid hydrolysis by lysosomal enzymes. In addition to it, we have tried to answer most of the possible questions related to lipophagy regulation at different levels. Moreover, in the last part of this review, we have discussed some of the pathological states due to the accumulation of these LDs and their possible treatments under the light of currently available findings.

scholarly journals Human Long Noncoding RNA Interactome: Detection, Characterization and Function

2020 ◽  
Vol 21 (3) ◽  
pp. 1027 ◽  
Author(s):  
Kazimierczyk ◽  
Kasprowicz ◽  
Kasprzyk ◽  
Wrzesinski
Keyword(s):  
Noncoding Rna ◽  
Potential Role ◽  
Integrated Analysis ◽  
Biological Functions ◽  
Non Coding Rna ◽  
Non Coding Rnas ◽  
And Function ◽  
New Generation ◽  
Cellular Components ◽  
Proteins And Peptides

The application of a new generation of sequencing techniques has revealed that most of the genome has already been transcribed. However, only a small part of the genome codes proteins. The rest of the genome "dark matter” belongs to divergent groups of non-coding RNA (ncRNA), that is not translated into proteins. There are two groups of ncRNAs, which include small and long non-coding RNAs (sncRNA and lncRNA respectively). Over the last decade, there has been an increased interest in lncRNAs and their interaction with cellular components. In this review, we presented the newest information about the human lncRNA interactome. The term lncRNA interactome refers to cellular biomolecules, such as nucleic acids, proteins, and peptides that interact with lncRNA. The lncRNA interactome was characterized in the last decade, however, understanding what role the biomolecules associated with lncRNA play and the nature of these interactions will allow us to better understand lncRNA's biological functions in the cell. We also describe a set of methods currently used for the detection of lncRNA interactome components and the analysis of their interactions. We think that such a holistic and integrated analysis of the lncRNA interactome will help to better understand its potential role in the development of organisms and cancers.

scholarly journals Selective Autophagy inDrosophila

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ioannis P. Nezis
Keyword(s):  
Cellular Response ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Model Organism ◽  
Major Pathway ◽  
Selective Autophagy ◽  
Cytoplasmic Material ◽  
Evolutionarily Conserved ◽  
High Conservation

Autophagy is an evolutionarily conserved process of cellular self-eating and is a major pathway for degradation of cytoplasmic material by the lysosomal machinery. Autophagy functions as a cellular response in nutrient starvation, but it is also associated with the removal of protein aggregates and damaged organelles and therefore plays an important role in the quality control of proteins and organelles. Although it was initially believed that autophagy occurs randomly in the cell, during the last years, there is growing evidence that sequestration and degradation of cytoplasmic material by autophagy can be selective. Given the important role of autophagy and selective autophagy in several disease-related processes such as neurodegeneration, infections, and tumorigenesis, it is important to understand the molecular mechanisms of selective autophagy, especially at the organismal level.Drosophilais an excellent genetically modifiable model organism exhibiting high conservation in the autophagic machinery. However, the regulation and mechanisms of selective autophagy inDrosophilahave been largely unexplored. In this paper, I will present an overview of the current knowledge about selective autophagy inDrosophila.

scholarly journals The molecular basis of selective autophagy

2012 ◽  
Vol 34 (2) ◽  
pp. 24-30 ◽  
Author(s):  
Doris Popovic ◽  
Ivan Dikic
Keyword(s):  
Molecular Basis ◽  
Membrane Vesicles ◽  
Degradation Process ◽  
Degradation Pathway ◽  
Selective Autophagy ◽  
Intracellular Degradation ◽  
Selective Degradation ◽  
Evolutionarily Conserved ◽  
The Family ◽  
Cellular Components

Autophagy is an evolutionarily conserved intracellular degradation process, through which large cellular cargos are sequestered into double-membrane vesicles (autophagosomes) and delivered to the lysosome. Starvation-induced autophagy represents a general non-selective degradation pathway that breaks down cellular components for energy replenishment. Alternatively, selective autophagy targets specific organelles, protein aggregates or invading pathogens that need to be precisely removed from the cell during development or pathogenic infection. Selective autophagy receptors noncovalently bind to the family of ATG8 modifiers and can be controlled by post-translational protein modifications, including ubiquitination and phosphorylation. In this article, we review recent advances in our understanding of the molecular basis of cargo selection in autophagy.

scholarly journals Defective Autophagy in Sf1 Neurons Perturbs the Metabolic Response to Fasting and Causes Mitochondrial Dysfunction

2020 ◽  
Author(s):  
Bérengère Coupé ◽  
Corinne Leloup ◽  
Julien Maillard ◽  
Luc Pénicaud ◽  
Tamas L. Horvath ◽  
...  
Keyword(s):  
Cellular Response ◽  
Energy Homeostasis ◽  
Metabolic Response ◽  
Ventromedial Nucleus ◽  
Related Gene ◽  
Physiological Processes ◽  
Evolutionarily Conserved ◽  
Central Response ◽  
Altered Regulation ◽  
Cellular Components

AbstractObjectiveThe ventromedial nucleus of the hypothalamus (VMH) is a critical component of the forebrain pathways that regulate energy homeostasis. It also plays an important role in the metabolic response to fasting. However, the mechanisms contributing to these physiological processes remain elusive. Autophagy is an evolutionarily conserved mechanism that maintains cellular homeostasis by turning over cellular components and providing nutrients to the cells during starvation. Here we investigated the importance of the autophagy-related gene Atg7 in Sf1-expressing neurons of the VMH in control and fasted conditions.MethodsWe generated Sf1-Cre; Atg7loxP/loxP mice and examined their metabolic and cellular response to fasting.ResultsFasting induces autophagy in the VMH, and mice lacking Atg7 in Sf1-expressing neurons display altered regulation in glucose and leptin homeostasis and impaired energy expenditure regulation in response to fasting. Moreover, loss of Atg7 in Sf1 neurons causes alterations in the central response to fasting. Furthermore, alterations in mitochondria morphology and activity are observed in mutant mice.ConclusionTogether, these data show that autophagy is nutritionally regulated in VMH neurons and that VMH autophagy participates in the control of energy homeostasis during fasting.

Oxygen and cancer

2019 ◽  
pp. 255-269
Author(s):  
Adrian L. Harris ◽  
Margaret Ashcroft
Keyword(s):  
Cellular Response ◽  
Cell Types ◽  
Tumour Microenvironment ◽  
Solid Tumours ◽  
Adaptive Responses ◽  
Tumour Vasculature ◽  
Evolutionarily Conserved ◽  
And Function ◽  
Different Cell Types ◽  
The Impact

Oxygen is required for most multicellular, aerobic organisms to survive and function. The vasculature provides the conduit for delivering oxygen via haemoglobin in the blood to organs, tissues, and cells. In diseases such as cancer, low tissue oxygenation or hypoxia occurs in solid tumours because of an inadequate supply of oxygen due to aberrant tumour vasculature. Hypoxia is a key feature of most solid tumours and underlies many of the processes associated with how cancer progresses; including tumour cell survival and proliferation, genetic instability, immune responses, angiogenesis, invasion and metastasis, and metabolic adaptive responses. Solid tumours contain several different cell types that respond to hypoxia within the tumour microenvironment. Hypoxia-inducible factors (HIFs) are a highly evolutionarily conserved family of dimeric transcription factors that are central to mediating the cellular response to hypoxia by regulating the expression of a diverse array of targets. Hypoxia and HIF activation is associated with treatment failure, resistance, and poor clinical outcomes. This chapter will provide an overview of the role of hypoxia in cancer, outline the methods used to measure hypoxia clinically, and discuss the impact of hypoxia on current front-line therapies being used to treat cancer.

Structure and Function of Angiopoietin-like Protein 3 (ANGPTL3) in Atherosclerosis

2020 ◽  
Vol 27 (31) ◽  
pp. 5159-5174 ◽  
Author(s):  
Xinjie Lu
Keyword(s):  
Low Density Lipoprotein ◽  
Lipoprotein Metabolism ◽  
Density Lipoprotein ◽  
Structure And Function ◽  
Biological Functions ◽  
Pharmacological Management ◽  
Vascular Growth ◽  
Promising Target ◽  
And Function ◽  
Systematic Appraisal

Background:Angiopoietin-Like Proteins (ANGPTLs) are structurally related to the angiopoietins. A total of eight ANGPTLs (from ANGPTL1 to ANGPTL8) have been identified so far. Most ANGPTLs possess multibiological functions on lipid metabolism, atherosclerosis, and cancer. Among them, ANGPTL3 has been shown to regulate the levels of Very Low-Density Lipoprotein (VLDL) made by the liver and play a crucial role in human lipoprotein metabolism.Method:A systematic appraisal of ANGPTLs was conducted, focusing on the main features of ANGPTL3 that has a significant role in atherosclerosis.Results:Angiopoietins including ANGPTL3 are vascular growth factors that are highly specific for endothelial cells, perform a variety of other regulatory activities to influence inflammation, and have been shown to possess both pro-atherosclerotic and atheroprotective effects.Conclusion:ANGPTL3 has been demonstrated as a promising target in the pharmacological management of atherosclerosis. However, many questions remain about its biological functions.

scholarly journals A rapid, parasite-dependent cellular response to Dirofilaria immitis in the Mongolian jird (Meriones unguiculatus)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Christopher C. Evans ◽  
Katherine M. Day ◽  
Yi Chu ◽  
Bridget Garner ◽  
Kaori Sakamoto ◽  
...  
Keyword(s):  
Cellular Response ◽  
Dirofilaria Immitis ◽  
Cell Attachment ◽  
Early Response ◽  
Meriones Unguiculatus ◽  
Filarial Parasite ◽  
Immune Mediated ◽  
Secretory Products ◽  
Species Specific

Abstract Background The Mongolian jird (Meriones unguiculatus) has long been recognized as a permissive host for the filarial parasite Brugia malayi; however, it is nonpermissive to another filarial parasite, canine heartworm (Dirofilaria immitis). By elucidating differences in the early response to infection, we sought to identify mechanisms involved in the species-specific clearance of these parasites. We hypothesized that the early clearance of D. immitis in intraperitoneal infection of the jird is immune mediated and parasite species dependent. Methods Jird peritoneal exudate cells (PECs) were isolated and their attachment to parasite larvae assessed in vitro under various conditions: D. immitis and B. malayi cultured separately, co-culture of both parasites, incubation before addition of cells, culture of heat-killed parasites, and culture with PECs isolated from jirds with mature B. malayi infection. The cells attaching to larvae were identified by immunohistochemistry. Results In vitro cell attachment to live D. immitis was high (mean = 99.6%) while much lower for B. malayi (mean = 5.56%). This species-specific attachment was also observed when both filarial species were co-cultured, with no significant change from controls (U(9, 14) = 58.5, p = 0.999). When we replicated these experiments with PECs derived from jirds subcutaneously infected with B. malayi, the results were similar (99.4% and 4.72% of D. immitis and B. malayi, respectively, exhibited cell attachment). Heat-killing the parasites significantly reduced cell attachment to D. immitis (mean = 71.9%; U(11, 14) = 7.5, p < 0.001) while increasing attachment to B. malayi (mean = 16.7%; U(9, 15) = 20, p = 0.002). Cell attachment to both species was reduced when larvae were allowed a 24-h pre-incubation period prior to the addition of cells. The attaching cells were identified as macrophages by immunohistochemistry. Conclusions These results suggest a strongly species-dependent response from which B. malayi could not confer protection by proxy in co-culture. The changes in cell attachment following heat-killing and pre-incubation suggest a role for excretory/secretory products in host immune evasion and/or antigenicity. The nature of this attachment is the subject of ongoing study and may provide insight into filarial host specificity.

scholarly journals Identification and Functional Analysis of Apoptotic Protease Activating Factor-1 (Apaf-1) from Spodoptera litura

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 64
Author(s):  
Haihao Ma ◽  
Xiumei Yan ◽  
Lin Yan ◽  
Jingyan Zhao ◽  
Jiping Song ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Actinomycin D ◽  
Titration Calorimetry ◽  
Apoptosis Pathway ◽  
Downstream Effector ◽  
Lepidopteran Insects ◽  
Evolutionarily Conserved ◽  
Effector Caspases ◽  
And Function

Apoptotic protease activating factor-1 (Apaf-1) is an adaptor molecule, essential for activating initiator caspase and downstream effector caspases, which directly cause apoptosis. In fruit flies, nematodes, and mammals, Apaf-1 has been extensively studied. However, the structure and function of Apaf-1 in Lepidoptera remain unclear. This study identified a novel Apaf-1 from Spodoptera litura, named Sl-Apaf-1. Sl-Apaf-1 contains three domains: a CARD domain, as well as NOD and WD motifs, and is very similar to mammalian Apaf-1. Interference of Sl-apaf-1 expression in SL-1 cells blocked apoptosis induced by actinomycin D. Overexpression of Sl-apaf-1 significantly enhances apoptosis induced by actinomycin D in Sf9/SL-1/U2OS cells, suggesting that the function of Sl-Apaf-1 is evolutionarily conserved. Furthermore, Sl-Apaf-1 could interact with Sl-caspase-5 (a homologue of mammalian caspase-9) and yielded a binding affinity of 1.37 × 106 M–1 according isothermal titration calorimetry assay. Initiator caspase (procaspase-5) of S. litura could be activated by Sl-Apaf-1 (without WD motif) in vitro, and the activated Sl-caspase-5 could cleave Sl-procaspase-1 (a homologue of caspase-3 in mammals), which directly caused apoptosis. This study demonstrates the key role of Sl-Apaf-1 in the apoptosis pathway, suggesting that the apoptosis pathway in Lepidopteran insects and mammals is conserved.

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