Read by QxMD icon Read

26S proteasome

Richard S Marshall, David C Gemperline, Richard D Vierstra
The 26S proteasome is a highly dynamic, multisubunit, ATP-dependent protease that plays a central role in cellular housekeeping and many aspects of plant growth and development by degrading aberrant polypeptides and key cellular regulators that are first modified by ubiquitin. Although the 26S proteasome was originally enriched from plants over 30 years ago, only recently have significant advances been made in our ability to isolate and study the plant particle. Here, we describe two robust methods for purifying the 26S proteasome and its subcomplexes from Arabidopsis thaliana; one that involves conventional chromatography techniques to isolate the complex from wild-type plants, and another that employs the genetic replacement of individual subunits with epitope-tagged variants combined with affinity purification...
2017: Methods in Molecular Biology
Ewa Waclawek, Ewa Joachimiak, Malgorzata Hanna Hall, Hanna Fabczak, Dorota Wloga
Katanin is a microtubule severing protein that functions as a heterodimer composed of an AAA domain catalytic subunit, p60, and a regulatory subunit, a WD40 repeat protein, p80. Katanin-dependent severing of microtubules is important for proper execution of key cellular activities including cell division, migration, and differentiation. Published data obtained in C. elegans, Xenopus and mammals indicate that katanin is regulated at multiple levels including transcription, posttranslational modifications (of both katanin and microtubules) and degradation...
October 11, 2016: Molecular Microbiology
Yuntao Shi, Marcus J C Long, Masha M Rosenberg, Shican Li, Aimee Kobjack, Philip Lessans, Rory T Coffey, Lizbeth Hedstrom
Targeted protein degradation is a promising strategy for drug design and functional assessment. Several small molecule approaches have been developed that localize target proteins to ubiquitin ligases, inducing ubiquitination and subsequent degradation by the 26S proteasome. We discovered that the degradation of a target protein can also be induced by a recognition ligand linked to tert-butyl carbamate (Boc3)-protected arginine (B3A). Here we show that this process requires the proteasome, but does not involve ubiquitination of the target protein...
October 5, 2016: ACS Chemical Biology
Chao Luo, Xiao-Teng Cai, Jin Du, Tao-Lan Zhao, Peng-Fei Wang, Ping-Xia Zhao, Rui Liu, Qi Xie, Xiao-Feng Cao, Cheng-Bin Xiang
Oxidative stress is unavoidable for aerobic organisms. When abiotic and biotic stresses are encountered, oxidative damage could occur in cells. To avoid this damage, defense mechanisms must be timely and efficiently modulated. While the response to oxidative stress has been extensively studied in plants, little is known about how the activated response is switched off when oxidative stress is diminished. By studying Arabidopsis mutant paraquat tolerance3, we identified the genetic locus PARAQUAT TOLERANCE3 (PQT3) as a major negative regulator of oxidative stress tolerance...
September 2016: PLoS Genetics
Marija Iljina, Laura Tosatto, Minee L Choi, Jason C Sang, Yu Ye, Craig D Hughes, Clare E Bryant, Sonia Gandhi, David Klenerman
The protein alpha-synuclein (αS) self-assembles into toxic beta-sheet aggregates in Parkinson's disease, while it is proposed that αS forms soluble alpha-helical multimers in healthy neurons. Here, we have made αS multimers in vitro using arachidonic acid (ARA), one of the most abundant fatty acids in the brain, and characterized them by a combination of bulk experiments and single-molecule Fӧrster resonance energy transfer (sm-FRET) measurements. The data suggest that ARA-induced oligomers are alpha-helical, resistant to fibril formation, more prone to disaggregation, enzymatic digestion and degradation by the 26S proteasome, and lead to lower neuronal damage and reduced activation of microglia compared to the oligomers formed in the absence of ARA...
September 27, 2016: Scientific Reports
B M Kirilenko, E N Grineva, D S Karpov, V L Karpov
26S proteasome is an ATP-dependent protease complex that takes part in cell homeostasis maintenance by the selective degradation of regulatory and damaged proteins. The proteasomal genes expression in Saccharomyces cerevisiae yeast is coordinately regulated by the system, which consists of the Rpn4 transcription factor and its binding site, called PACE. The ability to modulate proteasomal activity by changing the expression of its genes is an essential tool that can be used in fundamental studies devoted to the mechanisms of proteasome dependent cell processes, as well as in applied research for developing strategies to correct proteasome activity in some pathological processes...
July 2016: Molekuliarnaia Biologiia
Gabriel Nasri Marzuca-Nassr, Kaio Fernando Vitzel, Luís Gustavo De Sousa, Gilson M Murata, Amanda Rabello Crisma, Carlos Flores Rodrigues Junior, Phablo Abreu, Rosângela Pavan Torres, Jorge Mancini-Filho, Sandro M Hirabara, Philip Newsholme, Rui Curi
The effects of either eicosapentaenoic (EPA)- or docosahexaenoic (DHA)-rich fish oils on hindlimb suspension (HS)-induced muscle disuse atrophy were compared. Daily oral supplementations (0.3 mL/100 g b.w.) with mineral oil (MO) or high EPA or high DHA fish oils were performed in adult rats. After 2 weeks, the animals were subjected to HS for further 2 weeks. The treatments were maintained alongside HS At the end of 4 weeks, we evaluated: body weight gain, muscle mass and fat depots, composition of fatty acids, cross-sectional areas (CSA) of the soleus muscle and soleus muscle fibers, activities of cathepsin L and 26S proteasome, and content of carbonylated proteins in the soleus muscle...
September 2016: Physiological Reports
Eunju Im, Jong Bok Yoon, Han-Woong Lee, Kwang Chul Chung
Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase, an RNA-dependent DNA polymerase that elongates telomeric DNA. hTERT displays several extra-telomeric functions that are independent of its telomere-regulatory function, including tumor progression and neuronal cell death regulation. In this study, we evaluated these additional hTERT non-telomeric functions. We determined that hTERT interacts with several 19S and 20S proteasome subunits. The 19S regulatory particle and 20S core particle are part of 26S proteasome complex, which plays a central role in ubiquitin-dependent proteolysis...
September 20, 2016: Journal of Cellular Physiology
Anna Maria Santoro, Irene Monaco, Francesco Attanasio, Valeria Lanza, Giuseppe Pappalardo, Marianna Flora Tomasello, Alessandra Cunsolo, Enrico Rizzarelli, Ada De Luigi, Mario Salmona, Danilo Milardi
Due to their altered metabolism cancer cells are more sensitive to proteasome inhibition or changes of copper levels than normal cells. Thus, the development of copper complexes endowed with proteasome inhibition features has emerged as a promising anticancer strategy. However, limited information is available about the exact mechanism by which copper inhibits proteasome. Here we show that Cu(II) ions simultaneously inhibit the three peptidase activities of isolated 20S proteasomes with potencies (IC50) in the micromolar range...
2016: Scientific Reports
Lian Jin, Qingqing Qin, Yu Wang, Yingying Pu, Lifang Liu, Xing Wen, Shaoyi Ji, Jianguo Wu, Chunhong Wei, Biao Ding, Yi Li
The phytohormone auxin plays critical roles in regulating myriads of plant growth and developmental processes. Microbe infection can disturb auxin signaling resulting in defects in these processes, but the underlying mechanisms are poorly understood. Auxin signaling begins with perception of auxin by a transient co-receptor complex consisting of an F-box transport inhibitor response 1/auxin signaling F-box (TIR1/AFB) protein and an auxin/indole-3-acetic acid (Aux/IAA) protein. Auxin binding to the co-receptor triggers ubiquitination and 26S proteasome degradation of the Aux/IAA proteins, leading to subsequent events, including expression of auxin-responsive genes...
September 2016: PLoS Pathogens
Chao Wu, Ye Liu, Xiangxiang Gu, Tianhui Zhu, Shuang Yang, Wei Sun
In eukaryotic cells, the post-translational modification of proteins by ubiquitin or ubiquitin-like proteins (UBLs) is the most common trigger for protein degradation and is involved in the regulation of a wide range of biological processes. FAT10 (HLA-F-adjacent transcript 10), which belongs to the UBL family, is activated specifically through the UBA6-USE1 cascade and targets substrates covalently for 26S proteasomal degradation. LMO2 is a well-recognized transcriptional regulator in hematopoietic and endothelial systems; however, it is predominantly located in the cytoplasm of epithelium-derived cells...
September 23, 2016: Biochemical and Biophysical Research Communications
Tao Fan, Zhixin Huang, Lei Chen, Wei Wang, Boyou Zhang, Yao Xu, Shize Pan, Zhangfan Mao, Hao Hu, Qing Geng
The activation of autophagy has been demonstrated to exert protective roles during hypoxia-reoxygenation (H/R)-induced brain injuries. This study aimed to investigate whether and how preconditioning with a proteasome inhibitor (MG-132), a proteasome promoter (Adriamycin, ADM), an autophagy inhibitor (3-methyladenine, 3-MA) and an autophagy promoter (Rapamycin, Rap) affected endoplasmic reticulum stress (ERS), the ubiquitin-proteasome system (UPS), autophagy, inflammation and apoptosis. Ubiquitin protein and 26S proteasome activity levels were decreased by MG-132 pretreatment but increased by ADM pretreatment at 2h, 4h and 6h following H/R treatment...
August 26, 2016: European Journal of Pharmacology
Ken-Ichi Kubo, Mai Tsukahara, Sota Fujii, Kohji Murase, Yuko Wada, Tetsuyuki Entani, Megumi Iwano, Seiji Takayama
Self-incompatibility (SI) in flowering plants is a genetic reproductive barrier to distinguish self- and non-self pollen to promote outbreeding. In Solanaceae, self-pollen is rejected by the ribonucleases expressed in the styles (S-RNases), via its cytotoxic function. On the other side, male-determinant is the S-locus F-box proteins (SLFs) expressed in pollen. Multiple SLFs collaboratively detoxify non-self S-RNases; therefore non-self recognition is the mode of self-/non-self discrimination in Solanaceae. It is considered that SLFs function as a substrate-recognition module of Skp1-Cullin1-F-box (SCF) complex that inactivates non-self S-RNases via their polyubiquitination that leads to degradation by 26S proteasome...
August 26, 2016: Plant & Cell Physiology
Yasuyuki Yamada, Fumihiko Sato
Benzylisoquinoline alkaloids (BIQ) are among the most structurally diverse and pharmaceutically valuable secondary metabolites. A plant-specific WRKY-type transcription factor, CjWRKY1, was isolated from Coptis japonica and identified as a transcriptional activator of BIQ biosynthesis. However, the expression of CjWRKY1 gene alone was not sufficient for the activation of genes encoding biosynthetic enzymes. Here, we report the importance of post-translational regulation of CjWRKY1 in BIQ biosynthesis. First, we detected the differential accumulation of CjWRKY1 protein in two cell lines with similar CjWRKY1 gene expression but different levels of accumulated alkaloids...
2016: Scientific Reports
Won-Hee Song, Young-Joo Yi, Miriam Sutovsky, Stuart Meyers, Peter Sutovsky
Maternal inheritance of mitochondria and mtDNA is a universal principle in human and animal development, guided by selective ubiquitin-dependent degradation of the sperm-borne mitochondria after fertilization. However, it is not clear how the 26S proteasome, the ubiquitin-dependent protease that is only capable of degrading one protein molecule at a time, can dispose of a whole sperm mitochondrial sheath. We hypothesized that the canonical ubiquitin-like autophagy receptors [sequestosome 1 (SQSTM1), microtubule-associated protein 1 light chain 3 (LC3), gamma-aminobutyric acid receptor-associated protein (GABARAP)] and the nontraditional mitophagy pathways involving ubiquitin-proteasome system and the ubiquitin-binding protein dislocase, valosin-containing protein (VCP), may act in concert during mammalian sperm mitophagy...
September 6, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jesse D Woodson
Contents 36 I. 36 II. 37 III. 37 IV. 38 V. 39 VI. 40 VII. 40 40 References 40 SUMMARY: All organisms require the ability to sense their surroundings and adapt. Such capabilities allow them to thrive in a wide range of habitats. This is especially true for plants, which are sessile and have to be genetically equipped to withstand every change in their environment. Plants and other eukaryotes use their energy-producing organelles (i.e. mitochondria and chloroplasts) as such sensors. In response to a changing cellular or external environment, these organelles can emit 'retrograde' signals that alter gene expression and/or cell physiology...
October 2016: New Phytologist
Curtis Brandt, Pamela J McFie, Scot J Stone
Acyl-CoA:1,2-diacylglycerol acyltransferase (DGAT)-2 is one of the two DGAT enzymes that catalyzes the synthesis of triacylglycerol, which is an important form of stored energy for eukaryotic organisms. There is currently limited information available regarding how DGAT2 and triacylglycerol synthesis are regulated. Recent studies have indicated that DGAT2 can be regulated by changes in gene expression. How DGAT2 is regulated post-transcriptionally remains less clear. In this study, we demonstrated that DGAT2 is a very unstable protein and is rapidly degraded in an ubiquitin-dependent manner via the proteasome...
October 15, 2016: Biochemical Journal
Gina Sanchez, Daniela Berrios, Ivonne Olmedo, Javier Pezoa, Jaime A Riquelme, Luis Montecinos, Zully Pedrozo, Paulina Donoso
Inhibitors of the ubiquitin-proteasome system improve hemodynamic parameters and decrease the infarct size after ischemia reperfusion. The molecular basis of this protection is not fully understood since most available data report inhibition of the 26 proteasome after ischemia reperfusion. The decrease in cellular ATP levels during ischemia leads to the dissociation of the 26S proteasome into the 19S regulatory complex and the 20S catalytic core, which results in protein degradation independently of ubiquitination...
2016: PloS One
Gary S McDowell, Anna Philpott
The small protein modifier, ubiquitin, can be covalently attached to proteins in the process of ubiquitylation, resulting in a variety of functional outcomes. In particular, the most commonly-associated and well-studied fate for proteins modified with ubiquitin is their ultimate destruction: degradation by the 26S proteasome via the ubiquitin-proteasome system, or digestion in lysosomes by proteolytic enzymes. From the earliest days of ubiquitylation research, a reliable and versatile "cell-in-a-test-tube" system has been employed in the form of cytoplasmic extracts from the eggs and embryos of the frog Xenopus laevis...
August 16, 2016: International Journal of Developmental Biology
Qing Liu, Qin Wang, Bin Liu, Wei Wang, Xu Wang, Joon Park, Zhenming Yang, Xinglin Du, Mingdi Bian, Chentao Lin
Cryptochromes are blue light receptors regulated by light-dependent ubiquitination and degradation in both plant and animal lineages. The Arabidopsis genome encodes two cryptochromes, CRY1 and CRY2, of which CRY2 undergoes blue light-dependent ubiquitination and 26S proteasome-dependent degradation. The molecular mechanism regulating blue light-dependent proteolysis of CRY2 remains not fully understood. We found that the F-box proteins ZTL and LKP2, which mediate blue-light suppression of degradation of the CRY2 signaling partner CIB1, are not required for the blue light-dependent CRY2 degradation...
August 11, 2016: Plant & Cell Physiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"