scholarly journals The γTuRC Revisited: A Comparative Analysis of Interphase and Mitotic Human γTuRC Redefines the Set of Core Components and Identifies the Novel Subunit GCP8

2010 ◽  
Vol 21 (22) ◽  
pp. 3963-3972 ◽  
Author(s):  
Neus Teixidó-Travesa ◽  
Judit Villén ◽  
Cristina Lacasa ◽  
Maria Teresa Bertran ◽  
Marco Archinti ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Comparative Analysis ◽  
Protein Complex ◽  
The Novel ◽  
Microtubule Network ◽  
Microtubule Polymerization ◽  
Open Ring ◽  
Core Components ◽  
Ring Complexes ◽  
Ring Shaped Structure

The γ-tubulin complex is a multi-subunit protein complex that nucleates microtubule polymerization. γ-Tubulin complexes are present in all eukaryotes, but size and subunit composition vary. In Drosophila, Xenopus, and humans large γ-tubulin ring complexes (γTuRCs) have been described, which have a characteristic open ring-shaped structure and are composed of a similar set of subunits, named γ-tubulin, GCPs 2-6, and GCP-WD in humans. Despite the identification of these proteins, γTuRC function and regulation remain poorly understood. Here we establish a new method for the purification of native human γTuRC. Using mass spectrometry of whole protein mixtures we compared the composition of γTuRCs from nonsynchronized and mitotic human cells. Based on our analysis we can define core subunits as well as more transient interactors such as the augmin complex, which associates specifically with mitotic γTuRCs. We also identified GCP8/MOZART2 as a novel core subunit that is present in both interphase and mitotic γTuRCs. GCP8 depletion does not affect γTuRC assembly but interferes with γTuRC recruitment and microtubule nucleation at interphase centrosomes without disrupting general centrosome structure. GCP8-depleted cells do not display any obvious mitotic defects, suggesting that GCP8 specifically affects the organization of the interphase microtubule network.

Recommendations for Test Lab Regarding Transition to New Requirements GOST ISO/IEC 17025–2019

2020 ◽  
Vol 86 (2) ◽  
pp. 69-78
Author(s):  
S. N. Gusarova ◽  
Yu. M. Erokhina ◽  
D. I. Kramok ◽  
E. I. Khunuzidi
Keyword(s):  
Comparative Analysis ◽  
Russian Federation ◽  
Transition Period ◽  
Process Approach ◽  
National Standard ◽  
The Novel ◽  
Self Assessment ◽  
Testing Laboratories ◽  
The Russian Federation ◽  
Practical Level

Since September 1, 2019, GOST ISO/IEC 17025–2019 has been enacted as a national standard in the Russian Federation. The novel standard imposes a number of fundamentally new requirements for testing laboratories (hereinafter referred to as the IL or laboratory), and also supplements and specifies the requirements previously regulated by GOST ISO/IEC 17025–2009. In this regard, in order to transfer laboratories to the new requirements, the FSA issued an order in August 2019 listing the mandatory activities that IL must fulfill to bring their activities in line with the new requirements. However, a transition period desired for matching these requirements is absent on a practical level for a number of the laboratories. The purpose of the article is to facilitate a gentle, efficient and pain-free move from the requirements of GOST ISO/IEC 17025–2009 to the new requirements of GOST ISO/IEC 17025–2019, including compliance with new changes in accreditation criteria. We carried out a comparative analysis of the requirements of the new and previous versions of the standard and marked each new and significant item to which the laboratory should pay attention first of all. The new standard focuses on the application of the process approach, risk and opportunity management, as well as on implementation of the policy of impartiality, independence, minimization of competitive interests and confidentiality. The article describes the planning, implementation and monitoring of each event or phase of the transition of testing laboratories to new requirements. Moreover, the recommendations on the structure of the «Quality Manual» and self-assessment on the compliance of IL activities and QMS with the new requirements, including the use of statistical methods for substantiation of the correctness of the assessment are given as an example of the implementation of IL capabilities.

Age and architecture of the largest African Baobabs from Mayotte, France

2020 ◽  
Author(s):  
Adrian Patrut ◽  
Roxana Patrut ◽  
Laszlo Rakosy ◽  
Karl von Reden
Keyword(s):  
Life Cycle ◽  
Radiocarbon Dating ◽  
Cluster Structure ◽  
Radiocarbon Date ◽  
General State ◽  
Adansonia Digitata ◽  
Open Ring ◽  
The Indian Ocean ◽  
Ring Shaped Structure ◽  
Comoro Islands

The volcanic Comoro Islands, located in the Indian Ocean in between mainland Africa and Madagascar, host several thousand African baobabs (Adansonia digitata). Most of them are found in Mayotte, which currently belongs to France, as an overseas department. We report the investigation of the largest two baobabs of Mayotte, the Big baobab of Musical Plage and the largest baobab of Plage N’Gouja. The Big baobab of Musical Plage exhibits a cluster structure and consists of 5 fused stems, out of which 4 are common stems and one is a false stem. The baobab of Plage N’Gouja has an open ring-shaped structure and consists of 7 partially fused stems, out of which 3 stems are large and old, while 4 are young. Several wood samples were collected from both baobabs and analyzed via radiocarbon dating. The oldest dated sample from the baobab of Musical Plage has a radiocarbon date of 275 ± 25 BP, which corresponds to a calibrated calendar age of 365 ± 15 yr. On its turn, the oldest sample from Plage N’Gouja has a radiocarbon date of 231 ± 20 BP, which translates into a calibrated age of 265 ± 15 yr. These results indicate that the Big baobab of Musical Plage is around 420 years old, while the baobab of Plage N’Gouja has an age close to 330 years. In present, both baobabs are in a general state of deterioration with many broken or damaged branches, and the Baobab of Plage N’Gouja has several missing stems. These observations suggest that the two baobabs are in decline and, most likely, close to the end of their life cycle.

scholarly journals Comprehensive Analysis of RNA–Protein Complex Using Mass Spectrometry-Based Technology

2015 ◽  
Vol 53 (12) ◽  
pp. 850-859
Author(s):  
Keiichi IZUMIKAWA ◽  
Hideaki ISHIKAWA ◽  
Harunori YOSHIKAWA ◽  
Toshiaki ISOBE ◽  
Nobuhiro TAKAHASHI
Keyword(s):  
Mass Spectrometry ◽  
Protein Complex ◽  
Comprehensive Analysis

Mass spectrometry supported determination of protein complex structure

2013 ◽  
Vol 23 (2) ◽  
pp. 252-260 ◽  
Author(s):  
Thomas Walzthoeni ◽  
Alexander Leitner ◽  
Florian Stengel ◽  
Ruedi Aebersold
Keyword(s):  
Mass Spectrometry ◽  
Protein Complex ◽  
Complex Structure

Development and comparative analysis of yeast protein extraction protocols for mass spectrometry

2019 ◽  
Vol 567 ◽  
pp. 90-95 ◽  
Author(s):  
Lauana Fogaça de Almeida ◽  
Leonardo Nazário de Moraes ◽  
Lucilene Delazari dos Santos ◽  
Guilherme Targino Valente
Keyword(s):  
Mass Spectrometry ◽  
Comparative Analysis ◽  
Protein Extraction ◽  
Yeast Protein

Relationship between plasma and salivary melatonin and cortisol investigated by LC-MS/MS

2017 ◽  
Vol 55 (9) ◽  
Author(s):  
Martijn van Faassen ◽  
Rainer Bischoff ◽  
Ido P. Kema
Keyword(s):  
Mass Spectrometry ◽  
Equilibrium Dialysis ◽  
Added Value ◽  
The Novel ◽  
Plasma Melatonin ◽  
Disease States ◽  
Validation Criteria ◽  
Significant Difference ◽  
Salivary Melatonin ◽  
Free Plasma

AbstractBackground:Disturbance of the circadian rhythm has been associated with disease states, such as metabolic disorders, depression and cancer. Quantification of the circadian markers such as melatonin and cortisol critically depend on reliable and reproducible analytical methods. Previously, melatonin and cortisol were primarily analyzed separately, mainly using immunoassays.Methods:Here we describe the validation and application of a high-throughput liquid chromatography in combination with mass spectrometry (LC-MS/MS) method for the combined analysis of melatonin and cortisol in plasma and saliva. The LC-MS/MS method was validated according to international validation guidelines. We used this method to analyze total plasma, free plasma (as obtained by equilibrium dialysis) and saliva melatonin and cortisol in healthy adults.Results:Validation results for plasma and saliva melatonin and cortisol were well within the international validation criteria. We observed no difference between saliva collected by passive drooling or Salivette. Moreover, we noted a significant difference in saliva vs. free plasma melatonin. We observed on average 36% (95% CI: 4%–60%) higher salivary melatonin levels in comparison to free plasma melatonin, suggestive of local production of melatonin in the salivary glands.Conclusions:The novel outcome of this study is probably due to the high precision of our LC-MS/MS assay. These outcomes illustrate the added value of accurate and sensitive mass spectrometry based methods for the quantification of neuroendocrine biomarkers.

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