scholarly journals Importance of tyrosine phosphorylation for transmembrane signaling in plants

2021 ◽  
Vol 478 (14) ◽  
pp. 2759-2774
Author(s):  
Henning Mühlenbeck ◽  
Kyle W. Bender ◽  
Cyril Zipfel
Keyword(s):  
Plant Immunity ◽  
Critical Role ◽  
Sh2 Domain ◽  
Receptor Kinase ◽  
Post Translational Modification ◽  
The Core ◽  
Domains Of Life ◽  
Reversible Protein Phosphorylation ◽  
Signaling Modules

Reversible protein phosphorylation is a widespread post-translational modification fundamental for signaling across all domains of life. Tyrosine (Tyr) phosphorylation has recently emerged as being important for plant receptor kinase (RK)-mediated signaling, particularly during plant immunity. How Tyr phosphorylation regulates RK function is however largely unknown. Notably, the expansion of protein Tyr phosphatase and SH2 domain-containing protein families, which are the core of regulatory phospho-Tyr (pTyr) networks in choanozoans, did not occur in plants. Here, we summarize the current understanding of plant RK Tyr phosphorylation focusing on the critical role of a pTyr site (‘VIa-Tyr’) conserved in several plant RKs. Furthermore, we discuss the possibility of metazoan-like pTyr signaling modules in plants based on atypical components with convergent biochemical functions.

Pathogenesis of Age-related Cataract: a systematic review of proteomic studies

2020 ◽  
Vol 17 ◽  
Author(s):  
Christina Karakosta ◽  
Argyrios Tzamalis ◽  
Michalis Aivaliotis ◽  
Ioannis Tsinopoulos
Keyword(s):  
Systematic Review ◽  
Oxidant Stress ◽  
Critical Role ◽  
Human Lens ◽  
Nuclear Cataract ◽  
Cataract Formation ◽  
Post Translational Modification ◽  
Ability To Act ◽  
Age Related

Background/Objective:: The aim of this systematic review is to identify all the available data on human lens proteomics with a critical role to age-related cataract formation in order to elucidate the physiopathology of the aging lens. Materials and Methods:: We searched on Medline and Cochrane databases. The search generated 328 manuscripts. We included nine original proteomic studies that investigated human cataractous lenses. Results:: Deamidation was the major age-related post-translational modification. There was a significant increase in the amount of αA-crystallin D-isoAsp58 present at all ages, while an increase in the extent of Trp oxidation was apparent in cataract lenses when compared to aged normal lenses. During aging, enzymes with oxidized cysteine at critical sites included GAPDH, glutathione synthase, aldehyde dehydrogenase, sorbitol dehydrogenase, and PARK7. Conclusion:: D-isoAsp in αA crystallin could be associated with the development of age-related cataract in human, by contributing to the denaturation of a crystallin, and decreasing its ability to act as a chaperone. Oxidation of Trp may be associated with nuclear cataract formation in human, while the role of oxidant stress in age-related cataract formation is dominant.

Alternative Routes Toward Literacy for Individuals With Deafblindness

2020 ◽  
pp. 369-383
Author(s):  
Vassilios Argyropoulos ◽  
Magda Nikolaraizi ◽  
Maria Papazafiri
Keyword(s):  
Assistive Technology ◽  
Literacy Development ◽  
Critical Role ◽  
Literacy Skills ◽  
Literacy Experiences ◽  
Reading And Writing ◽  
Domains Of Life ◽  
Role Of Teachers ◽  
Alternative Routes

The aim of the current chapter is to describe alternative ways that can enhance literacy development for persons with deafblindness. The conventional concept of literacy, which concerns reading and writing, excludes persons with deafblindness from literacy experiences. Therefore, a broadened and more contemporary concept is supported, which incorporates communication. Within this broader concept, assistive technology can play an important role in the development of literacy and therefore facilitate the access of individuals who are deafblind in different domains of life. Furthermore, the paper emphasizes the critical role of teachers and the importance of training that will enable them to exploit assistive technology in order to enhance the literacy skills of persons who are deafblind.

scholarly journals In Silico Studies on Development of Novel Virostatic Agents against Bluetongue Virus

ISRN Virology ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Pandrangi Anupama
Keyword(s):  
Bluetongue Virus ◽  
Core Protein ◽  
Critical Role ◽  
Docking Studies ◽  
Site Specific ◽  
The Core ◽  
In Silico Studies ◽  
Vp7 Protein ◽  
Major Core Protein

The core of BTV is organized into three concentric structures of which VP7 protein forms the major core protein. The subcore consists of VP3 protein and the innermost part of the core is made of three minor proteins: VP1, VP4, and VP6. Earlier it was reported that core-like particles (CLPs) composed of viral VP7 and VP3 proteins were produced in order to study role of VP7 protein in intermolecular interactions in the BTV assembly process. Site specific mutational studies revealed that substitution of the single lysine residue of VP7 (Lys-255) by leucine abrogated CLP formation, indicating a critical role for this lysine. In the present study, homology modeling, mutagenesis, and docking studies were carried out in order to design potent leads in modulation of VP7 protein in abrogating CLP formation.

scholarly journals Small but Stylish: Pushing Innovation Ambidexterity in International Small and Medium Enterprises

2020 ◽  
Vol 6 (2) ◽  
pp. 54
Author(s):  
Faizah Mashahadi ◽  
Noor Hazlina Ahmad
Keyword(s):  
Conceptual Model ◽  
Entrepreneurial Orientation ◽  
Industrial Revolution ◽  
Small And Medium Enterprises ◽  
Critical Role ◽  
Innovation Activity ◽  
The Core ◽  
Enhance Efficiency ◽  
Medium Enterprises

Small and Medium Enterprises (SMEs) have been the core agents in accelerating growth and providing jobs opportunities for the nation. Indeed, with industrial revolution rapidly evolving, there is a stronger exigency for SMEs to explore new opportunities aims to enhance efficiency so that SMEs able to compete and grow internationally. Recent development has heightened the need for SMEs to involve in innovation activity as the means to improve competitiveness and sustaining performance becoming a reality. Many studies emphasize on the critical role of innovation ambidexterity in determining SMEs success but the existing studies yet to conclude the predecessor of innovation ambidexterity in internationally operated SMEs. This article aims to provide a conceptual model that explores the potential of international entrepreneurial orientation in determining innovation ambidexterity in international SMEs in Malaysia.

scholarly journals Mutation in ATG5 reduces autophagy and leads to ataxia with developmental delay

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Myungjin Kim ◽  
Erin Sandford ◽  
Damian Gatica ◽  
Yu Qiu ◽  
Xu Liu ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Neurodegenerative Disorders ◽  
Neurological Diseases ◽  
Critical Role ◽  
Wild Type ◽  
Autophagy Flux ◽  
The Core ◽  
Atg Genes ◽  
Autophagy Pathway

Autophagy is required for the homeostasis of cellular material and is proposed to be involved in many aspects of health. Defects in the autophagy pathway have been observed in neurodegenerative disorders; however, no genetically-inherited pathogenic mutations in any of the core autophagy-related (ATG) genes have been reported in human patients to date. We identified a homozygous missense mutation, changing a conserved amino acid, in ATG5 in two siblings with congenital ataxia, mental retardation, and developmental delay. The subjects' cells display a decrease in autophagy flux and defects in conjugation of ATG12 to ATG5. The homologous mutation in yeast demonstrates a 30-50% reduction of induced autophagy. Flies in which Atg5 is substituted with the mutant human ATG5 exhibit severe movement disorder, in contrast to flies expressing the wild-type human protein. Our results demonstrate the critical role of autophagy in preventing neurological diseases and maintaining neuronal health.

Proteasome activator Blm10 regulates transcription especially during aging

2021 ◽  
Vol 22 ◽  
Author(s):  
Yu-Shan Chen ◽  
Xia Han ◽  
Kui Lin ◽  
Tian-Xia Jiang ◽  
Xiao-Bo Qiu
Keyword(s):  
Critical Role ◽  
Regulation Of Gene Expression ◽  
Cellular Aging ◽  
Yeast Cells ◽  
Histone Marks ◽  
Proteasome Activator ◽  
The Core ◽  
Core Histones ◽  
The Stability

Background: Histones are basic elements of the chromatin, and are critical to controlling chromatin structure and transcription. The proteasome activator PA200 promotes the acetylation-dependent proteasomal degradation of the core histones during spermatogenesis, DNA repair, transcription and cellular aging, and maintains the stability of histone marks. Objective: The study aimed to explore whether the yeast ortholog of PA200, Blm10, promotes degradation of the core histones during transcription and regulates transcription especially during aging. Method: Protein degradation assays were performed to detect the role of Blm10 in histone degradation during transcription. mRNA profiles were compared in WT and mutant BY4741 or MDY510 yeast cells by RNA-sequencing. Results: The core histones can be degraded by the Blm10-proteasome in the non-replicating yeast, suggesting that Blm10 promotes the transcription-coupled degradation of the core histones. Blm10 preferentially regulates transcription in aged yeast, especially transcription of genes related to translation, amino acid metabolism and carbohydrate metabolism. Mutations of Blm10 at F2125/N2126 in its putative acetyl-lysine binding region abolished the Blm10-mediated regulation of gene expression. Conclusion: Blm10 promotes degradation of the core histones during transcription and regulates transcription especially during cellular aging, further supporting the critical role of PA200 in maintaining the stability of histone marks from the evolutionary view. These results should provide meaningful insights into the mechanisms underlying aging and the related diseases.

scholarly journals A Critical Role of Non-active Site Residues on Cyclooxygenase Helices 5 and 6 in the Control of Prostaglandin Stereochemistry at Carbon 15

2007 ◽  
Vol 282 (38) ◽  
pp. 28157-28163 ◽  
Author(s):  
Karin Valmsen ◽  
William E. Boeglin ◽  
Reet Järving ◽  
Ivar Järving ◽  
Külliki Varvas ◽  
...  
Keyword(s):  
Amino Acid ◽  
Active Site ◽  
Amino Acid Sequence Identity ◽  
Critical Role ◽  
Site Directed Mutagenesis ◽  
Single Amino Acid ◽  
Active Site Residues ◽  
The Core ◽  
The Difference

The correct stereochemistry of prostaglandins is a prerequisite of their biological activity and thus is under a strict enzymatic control. Recently, we cloned and characterized two cyclooxygenase (COX) isoforms in the coral Plexaura homomalla that share 97% amino acid sequence identity, yet form prostaglandins with opposite stereochemistry at carbon 15. The difference in oxygenation specificity is only partially accounted for by the single amino acid substitution in the active site (Ile or Val at position 349). For further elucidation of residues involved in the C-15 stereocontrol, a series of sequence swapping and site-directed mutagenesis experiments between 15R- and 15S-COX were performed. Our results show that the change in stereochemistry at carbon 15 of prostaglandins relates mainly to five amino acid substitutions on helices 5 and 6 of the coral COX. In COX proteins, these helices form a helix-turn-helix motif that traverses through the entire protein, contributing to the second shell of residues around the oxygenase active site; it constitutes the most highly conserved region where even slight changes result in loss of catalytic activity. The finding that this region is among the least conserved between the P. homomalla 15S- and 15R-specific COX further supports its significance in maintaining the desired prostaglandin stereochemistry at C-15. The results are particularly remarkable because, based on its strong conservation, the conserved middle of helix 5 is considered as central to the core structure of peroxidases, of which COX proteins are derivatives. Now we show that the same parts of the protein are involved in the control of oxygenation with 15R or 15S stereospecificity in the dioxygenase active site.

Oncogenic JAK2V617F requires an intact SH2-like domain for constitutive activation and induction of a myeloproliferative disease in mice

Blood ◽  
2010 ◽  
Vol 116 (22) ◽  
pp. 4600-4611 ◽  
Author(s):  
Sivahari P. Gorantla ◽  
Tobias N. Dechow ◽  
Rebekka Grundler ◽  
Anna Lena Illert ◽  
Christian Meyer zum Büschenfelde ◽  
...  
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Critical Role ◽  
Sh2 Domain ◽  
Receptor Expression ◽  
Cytokine Receptor ◽  
Myeloproliferative Disease ◽  
Constitutive Activation ◽  
Downstream Signaling ◽  
Strict Requirement

Abstract The oncogenic JAK2V617F mutation is found in myeloproliferative neoplasms (MPNs) and is believed to be critical for leukemogenesis. Here we show that JAK2V617F requires an intact SH2 domain for constitutive activation of downstream signaling pathways. In addition, there is a strict requirement of cytokine receptor expression for the activation of this oncogene. Further analysis showed that the SH2 domain mutation did not interfere with JAK2 membrane distribution. However, coimmunoprecipitated experiments revealed a role for the SH2 domain in the aggregation and cross-phosphorylation of JAK2V617F at the cell membrane. Forced overexpression of cytokine receptors could rescue the JAK2V617F SH2 mutant supporting a critical role of JAK2V617F abundance for constitutive activation. However, under physiologic cytokine receptor expression the SH2 domain is absolutely necessary for oncogenic JAK2V617F activation. This is demonstrated in a bone marrow transplantation model, in which an intact SH2 domain in JAK2V617F is required for the induction of an MPN-like disease. Thus, our results points to an indispensable role of the SH2 domain in JAK2V617F-induced MPNs.

scholarly journals Phosphorylation of Tyrosine Residues 31 and 118 on Paxillin Regulates Cell Migration through an Association with Crk in Nbt-II Cells

2000 ◽  
Vol 148 (5) ◽  
pp. 957-970 ◽  
Author(s):  
Valérie Petit ◽  
Brigitte Boyer ◽  
Delphine Lentz ◽  
Christopher E. Turner ◽  
Jean Paul Thiery ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Motility ◽  
Critical Role ◽  
Adaptor Protein ◽  
Signaling Molecules ◽  
Sh2 Domain ◽  
Wild Type ◽  
Tyrosine Residues ◽  
Pathological Conditions

Identification of signaling molecules that regulate cell migration is important for understanding fundamental processes in development and the origin of various pathological conditions. The migration of Nara Bladder Tumor II (NBT-II) cells was used to determine which signaling molecules are specifically involved in the collagen-mediated locomotion. We show here that paxillin is tyrosine phosphorylated after induction of motility on collagen. Overexpression of paxillin mutants in which tyrosine 31 and/or tyrosine 118 were replaced by phenylalanine effectively impaired cell motility. Moreover, stimulation of motility by collagen preferentially enhanced the association of paxillin with the SH2 domain of the adaptor protein CrkII. Mutations in both tyrosine 31 and 118 diminished the phosphotyrosine content of paxillin and prevented the formation of the paxillin–Crk complex, suggesting that this association is necessary for collagen-mediated NBT-II cell migration. Other responses to collagen, such as cell adhesion and spreading, were not affected by these mutations. Overexpression of wild-type paxillin or Crk could bypass the migration-deficient phenotype. Both the SH2 and the SH3 domains of CrkII are shown to play a critical role in this collagen-mediated migration. These results demonstrate the important role of the paxillin–Crk complex in the collagen-induced cell motility.

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