scholarly journals Conformational plasticity of the ULK3 kinase domain

2021 ◽  
Author(s):  
Sebastian Mathea ◽  
Eidarus Salah ◽  
Cynthia Tallant ◽  
Deep Chatterjee ◽  
Benedict-Tilman Berger ◽  
...  
Keyword(s):  
Protein Kinase ◽  
High Resolution ◽  
Substrate Recognition ◽  
Kinase Domain ◽  
Recognition Mechanism ◽  
Conformational Switch ◽  
Human Protein Kinase ◽  
Wide Range ◽  
Conformational Plasticity ◽  
Potential Substrate

The human protein kinase ULK3 regulates the timing of membrane abscission, thus being involved in exosome budding and cytokinesis. Herein, we present the first high-resolution structures of the ULK3 kinase domain. Its unique features are explored against the background of other ULK kinases. An inhibitor fingerprint indicates that ULK3 is highly druggable and capable of adopting a wide range of conformations. In accordance with this, we describe a conformational switch between the active and an inactive ULK3 conformation, controlled by the properties of the attached small-molecule binder. Finally, we discuss a potential substrate-recognition mechanism of the full-length ULK3 protein.

scholarly journals Genome-wide identification of MAPKKK genes and their responses to phytoplasma infection in Chinese jujube (Ziziphus jujuba Mill.)

2019 ◽  
Author(s):  
ZhiGuo Liu(Former Corresponding Author) ◽  
Lixin Wang ◽  
Chaoling Xue ◽  
Yuetong Chu ◽  
Weilin Gao ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Expression Profiles ◽  
Phylogenetic Analyses ◽  
Kinase Domain ◽  
Mitogen Activated Protein Kinase ◽  
Chinese Jujube ◽  
Mapk Cascades ◽  
Wide Range ◽  
Phytoplasma Infection ◽  
Gene Structures

Abstract Background Mitogen activated protein kinase (MAPK) cascades play vital roles in signal transduction in response to a wide range of biotic and abiotic stresses. In a previous study we identified ten ZjMAPKs and five ZjMAPKKs in the Chinese jujube genome. We found some members of ZjMAPKs and ZjMAPKKs may play key roles in the plant’s response to phytoplasma infection. But how these ZjMAPKKs are modulated by ZjMAPKKKs during the response process remains uncertain. Little information is available regarding MAPKKKs in Chinese jujube. Results A total of 56 ZjMAPKKKs were identified in the jujube genome. All contain the key S-TKc (serine/threonine protein kinase) domain which is distributed among all 12 chromosomes. Phylogenetic analyses show these ZjMAPKKKs can be classified into two subfamilies. Of these, 41 belong to the Raf subfamily and 15 to the MEKK subfamily. In addition, the ZjMAPKKKs in each subfamily share the same conserved motifs and gene structures. Only one pair of ZjMAPKKKs (15/16, on Chromosome 5) was found to be tandem duplicated. Using qPCR, the expression profiles of these MAPKKKs were investigated in response to infection with phytoplasma. In the three main infected tissues (witches’ broom leaves, phyllody leaves, apparently normal leaves), ZjMAPKKK26 and 45 were significantly up-regulated and ZjMAPKKK3, 43 and 50 were significantly down-regulated. While the ZjMAPKKK4, 10, 25 and 44 were significantly and highly induced in sterile cultivated tissues infected by phytoplasma, while ZjMAPKKK6, 7, 17, 18, 30, 34, 35, 37, 40, 41, 43, 46, 52 and 46 53 were significantly down-regulated. Conclusions For the first time, we present an identification and classification analysis of ZjMAPKKKs. Some ZjMAPKKKs genes possibly play key roles in response to phytoplasma infection. This study provides an initial understanding for the mechanisms through which ZjMAPKKKs are involved in the response of Chinese jujube to phytoplasma infection.

scholarly journals Genome-wide identification of MAPKKK genes and their responses to phytoplasma infection in Chinese jujube (Ziziphus jujuba Mill.)

2020 ◽  
Author(s):  
ZhiGuo Liu ◽  
Lixin Wang ◽  
Chaoling Xue ◽  
Yuetong Chu ◽  
Weilin Gao ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Expression Profiles ◽  
Phylogenetic Analyses ◽  
Kinase Domain ◽  
Mitogen Activated Protein Kinase ◽  
Chinese Jujube ◽  
Mapk Cascades ◽  
Wide Range ◽  
Phytoplasma Infection ◽  
Gene Structures

Abstract Background: Mitogen-activated protein kinase (MAPK) cascades play vital roles in signal transduction in response to a wide range of biotic and abiotic stresses. In a previous study, we identified ten ZjMAPKs and five ZjMAPKKs in the Chinese jujube genome. We found that some members of ZjMAPKs and ZjMAPKKs may play key roles in the plant’s response to phytoplasma infection. However, how these ZjMAPKKs are modulated by ZjMAPKKKs during the response process has not been elucidated. Little information is available regarding MAPKKKs in Chinese jujube.Results: A total of 56 ZjMAPKKKs were identified in the jujube genome. All of these kinases contain the key S-TKc (serine/threonine protein kinase) domain, which is distributed among all 12 chromosomes. Phylogenetic analyses show that these ZjMAPKKKs can be classified into two subfamilies. Specifically, 41 ZjMAPKKKs belong to the Raf subfamily, and 15 belong to the MEKK subfamily. In addition, the ZjMAPKKKs in each subfamily share the same conserved motifs and gene structures. Only one pair of ZjMAPKKKs (15/16, on chromosome 5) was found to be tandemly duplicated. Using qPCR, the expression profiles of these MAPKKKs were investigated in response to infection with phytoplasma. In the three main infected tissues (witches’ broom leaves, phyllody leaves, and apparently normal leaves), ZjMAPKKK26 and -45 were significantly upregulated, and ZjMAPKKK3, -43 and -50 were significantly downregulated. ZjMAPKKK4, -10, -25 and -44 were significantly and highly induced in sterile cultivated tissues infected by phytoplasma, while ZjMAPKKK6, -7, -17, -18, -30, -34, -35, -37, -40, -41, -43, -46, -52 and -53 were significantly downregulated.Conclusions: For the first time, we present an identification and classification analysis of ZjMAPKKKs. Some ZjMAPKKK genes may play key roles in the response to phytoplasma infection. This study provides an initial understanding of the mechanisms through which ZjMAPKKKs are involved in the response of Chinese jujube to phytoplasma infection.

Development of a conical anode Fe-gun for low voltage SEM

1988 ◽  
Vol 46 ◽  
pp. 978-979
Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Low Voltage ◽  
Irradiation Damage ◽  
Cold Cathode ◽  
Virtual Source ◽  
Source Position ◽  
Electrostatic Lens ◽  
Electrostatic Lenses ◽  
Wide Range

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.

Three-fold astigmatism: An important TEM aberration

1993 ◽  
Vol 51 ◽  
pp. 972-973 ◽  
Author(s):  
O.L. Krivanek ◽  
M.L. Leber
Keyword(s):  
High Resolution ◽  
Spatial Frequency ◽  
Field Emission ◽  
Azimuthal Angle ◽  
Hollow Cone ◽  
Small Probe ◽  
Wide Range ◽  
High Resolution Images ◽  
Image Position

Three-fold astigmatism resembles regular astigmatism, but it has 3-fold rather than 2-fold symmetry. Its contribution to the aberration function χ(q) can be written as:where A3 is the coefficient of 3-fold astigmatism, λ is the electron wavelength, q is the spatial frequency, ϕ the azimuthal angle (ϕ = tan-1 (qy/qx)), and ϕ3 the direction of the astigmatism.Three-fold astigmatism is responsible for the “star of Mercedes” aberration figure that one obtains from intermediate lenses once their two-fold astigmatism has been corrected. Its effects have been observed when the beam is tilted in a hollow cone over a wide range of angles, and there is evidence for it in high resolution images of a small probe obtained in a field emission gun TEM/STEM instrument. It was also expected to be a major aberration in sextupole-based Cs correctors, and ways were being developed for dealing with it on Cs-corrected STEMs.

Scanning tunneling microscopy of polymers: A status report

1989 ◽  
Vol 47 ◽  
pp. 330-331
Author(s):  
P.E. Russell ◽  
I.H. Musselman
Keyword(s):  
High Resolution ◽  
Scanning Tunneling Microscopy ◽  
Sample Surface ◽  
Atomic Scale ◽  
Constant Current ◽  
Scanning Tunneling ◽  
Status Report ◽  
Tunneling Microscopy ◽  
Research Issues ◽  
Wide Range

Scanning tunneling microscopy (STM) has evolved rapidly in the past few years. Major developments have occurred in instrumentation, theory, and in a wide range of applications. In this paper, an overview of the application of STM and related techniques to polymers will be given, followed by a discussion of current research issues and prospects for future developments. The application of STM to polymers can be conveniently divided into the following subject areas: atomic scale imaging of uncoated polymer structures; topographic imaging and metrology of man-made polymer structures; and modification of polymer structures. Since many polymers are poor electrical conductors and hence unsuitable for use as a tunneling electrode, the related atomic force microscopy (AFM) technique which is capable of imaging both conductors and insulators has also been applied to polymers.The STM is well known for its high resolution capabilities in the x, y and z axes (Å in x andy and sub-Å in z). In addition to high resolution capabilities, the STM technique provides true three dimensional information in the constant current mode. In this mode, the STM tip is held at a fixed tunneling current (and a fixed bias voltage) and hence a fixed height above the sample surface while scanning across the sample surface.

scholarly journals Expression of TTK, a novel human protein kinase, is associated with cell proliferation.

1992 ◽  
Vol 267 (22) ◽  
pp. 16000-16006
Author(s):  
G.B. Mills ◽  
R Schmandt ◽  
M McGill ◽  
A Amendola ◽  
M Hill ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase ◽  
Human Protein ◽  
Human Protein Kinase

scholarly journals Growth Promotion or Osmotic Stress Response: How SNF1-Related Protein Kinase 2 (SnRK2) Kinases Are Activated and Manage Intracellular Signaling in Plants

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1443
Author(s):  
Yoshiaki Kamiyama ◽  
Sotaro Katagiri ◽  
Taishi Umezawa
Keyword(s):  
Protein Kinase ◽  
Plant Growth ◽  
Osmotic Stress ◽  
Protein Function ◽  
Intracellular Signaling ◽  
Growth Promotion ◽  
Research Field ◽  
Dependent Manner ◽  
Related Protein ◽  
Wide Range

Reversible phosphorylation is a major mechanism for regulating protein function and controls a wide range of cellular functions including responses to external stimuli. The plant-specific SNF1-related protein kinase 2s (SnRK2s) function as central regulators of plant growth and development, as well as tolerance to multiple abiotic stresses. Although the activity of SnRK2s is tightly regulated in a phytohormone abscisic acid (ABA)-dependent manner, recent investigations have revealed that SnRK2s can be activated by group B Raf-like protein kinases independently of ABA. Furthermore, evidence is accumulating that SnRK2s modulate plant growth through regulation of target of rapamycin (TOR) signaling. Here, we summarize recent advances in knowledge of how SnRK2s mediate plant growth and osmotic stress signaling and discuss future challenges in this research field.

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