32 research outputs found
Nictaba homologs from Arabidopsis thaliana are involved in plant stress responses
Plants are constantly exposed to a wide range of environmental stresses, but evolved complicated adaptive and defense mechanisms which allow them to survive in unfavorable conditions. These mechanisms protect and defend plants by using different immune receptors located either at the cell surface or in the cytoplasmic compartment. Lectins or carbohydrate-binding proteins are widespread in the plant kingdom and constitute an important part of these immune receptors. In the past years, lectin research has focused on the stress-inducible lectins. The Nicotiana tabacum agglutinin, abbreviated as Nictaba, served as a model for one family of stress-related lectins. Here we focus on three non-chimeric Nictaba homologs from Arabidopsis thaliana, referred to as AN3, AN4, and AN5. Confocal microscopy of ArathNictaba enhanced green fluorescent protein (EGFP) fusion constructs transiently expressed in N. benthamiana or stably expressed in A. thaliana yielded fluorescence for AN4 and AN5 in the nucleus and the cytoplasm of the plant cell, while fluorescence for AN3 was only detected in the cytoplasm. RT-qPCR analysis revealed low expression for all three ArathNictabas in different tissues throughout plant development. Stress application altered the expression levels, but all three ArathNictabas showed a different expression pattern. Pseudomonas syringae infection experiments with AN4 and AN5 overexpression lines demonstrated a significantly higher tolerance of several transgenic lines to P. syringae compared to wild type plants. Finally, AN4 was shown to interact with two enzymes involved in plant defense, namely TGG1 and BGLU23. Taken together, our data suggest that the ArathNictabas represent stress-regulated proteins with a possible role in plant stress responses. On the long term this research can contribute to the development of more stress-resistant plants
Arabidopsis F-box protein containing a Nictaba-related lectin domain interacts with N-acetyllactosamine structures
The Arabidopsis thaliana genome contains a small group of bipartite F-box proteins, consisting of an N-terminal F-box domain and a C-terminal domain sharing sequence similarity with Nictaba, the jasmonate-induced glycan-binding protein (lectin) from tobacco. Based on the high sequence similarity between the C-terminal domain of these proteins and Nictaba, the hypothesis was put forward that the so-called F-box-Nictaba proteins possess carbohydrate-binding activity and accordingly can be considered functional homologs of the mammalian sugar-binding F-box or Fbs proteins which are involved in proteasomal degradation of glycoproteins. To obtain experimental evidence for the carbohydrate-binding activity and specificity of the A. thaliana F-box-Nictaba proteins, both the complete F-box-Nictaba sequence of one selected Arabidopsis F-box protein (in casu At2g02360) as well as the Nictaba-like domain only were expressed in Pichia pastoris and analyzed by affinity chromatography, agglutination assays and glycan micro-array binding assays. These results demonstrated that the C-terminal Nictaba-like domain provides the F-box-protein with a carbohydrate-binding activity that is specifically directed against N- and O-glycans containing N-acetyllactosamine (Galβ1-3GlcNAc and Galβ1-4GlcNAc) and poly-N-acetyllactosamine ([Galβ1-4GlcNAc](n)) as well as Lewis A (Galβ1-3(Fucα1-4)GlcNAc), Lewis X (Galβ1-4(Fucα1-3)GlcNAc, Lewis Y (Fucα1-2Galβ1-4(Fucα1-3)GlcNAc) and blood type B (Galα1-3(Fucα1-2)Galβ1-3GlcNAc) motifs. Based on these findings one can reasonably conclude that at least the A. thaliana F-box-Nictaba protein encoded by At2g02360 can act as a carbohydrate-binding protein. The results from the glycan array assays revealed differences in sugar-binding specificity between the F-box protein and Nictaba, indicating that the same carbohydrate-binding motif can accommodate unrelated oligosaccharides
The influence of glycation on a high pressure denaturation of ubiquitin
Synopsis The combination of deuterium-hydrogen exchange (DHX) and mass spectrometry (MS) can be used for studying a high pressure denaturation (HPD) of proteins. Herein we present the results of investigations of the influence of glycation on the HPD of ubiquitin. Application of various values of pressure causes different degrees of protein unfolding, resulting in molecules with a different number of protons available for exchange with deuterons. The dependence of this number on pressure gives information on the denaturation state of a protein. On the basis of the obtained results we can conclude that increasing number of fructosamine moieties in ubiquitin decreases the pressure required for its denaturation. It suggests that glycation moderately decreases the protein stability. The present study is the first example of application of hydrogen-deuterium exchange as a method of investigating the influence of posttranslational modification of protein on the HPD
Contemporary treatment options for male hypogonadism
Introduction
Male hypogonadism is a disease in which testicular function is impaired. Its symptoms are due to testosterone deficiency and most of them show low specificity. These include reduced libido, erectile dysfunction and mood disorders, among others. The biochemical indicator of hypogonadism is a testosterone concentration below 350 ng/ml (12nmol/L), according to the European Association of Urology (EAU). The increased incidence of hypogonadism is associated with aging and the presence of comorbidities such as type II diabetes and obesity. Men with testosterone deficiency have an increased risk of cardiovascular disease and premature death.
Goals
Summary of current reports on the diagnosis and treatment of hypogonadism. An overview of the advantages and disadvantages of the different types of formulations used in testosterone replacement therapy.
MethodsReview of literature available in PubMed and Google Scholar databases.
Conclusions
The medical interview, physical examination and ancillary tests help to classify hypogonadism appropriately. Measuring the concentration of gonadotropins, helps diversify primary from secondary hypogonadism. Testosterone replacement therapy (TRT) uses formulations that have varying release profiles, route of administration and drug formulation. The choice of testosterone product should involve age, lifestyle, and individual preferences of the patient
Wound packing trainee construction
Haemorrhage is one of the main causes of death in injuries in both civilian and military conditions. Controlling bleeding is the most important task facing the rescuer when helping a casualty. There are many ways to control bleeding, but these methods are often misused. Most of the methods described have their roots in battlefield medicine developed on the basis of experience from armed conflicts. Currently, there is a clear trend towards adapting tactical medicine solutions for civil rescues because they are effective and simple. Increased awareness among civilian rescuers and regular training will hopefully lead to more effective help for injured people. The authors' work focused on the construction of an effective trainer to mimic a hip wound and a practical examination of how training affects the time to stop bleeding using the wound packing technique
Chronic migraine prevention from the perspective of a family doctor: a literature review
Chronic migraine is a disease that significantly reduces the quality of life of patients. It affects millions of people around the world, and is common particularly among young women. Family physicians often encounter the problem of migraine headaches in their daily practice. The diagnostic problem results from absence of tests or imaging studies that can clearly indicate the cause of the headache. In order to establish a diagnosis and exclude secondary sources of pain, doctors focus on a detailed medical history and analysis of symptoms presented over time. Preventive treatment of migraine requires appropriate drug selection after weighing the benefits and risks for each patient. This review paper presents and briefly discusses selected pharmacological and non-pharmacological methods used in migraine prevention. They were selected by searching the PubMed Internet database. The presented non-pharmacological methods include the use of nutraceutics, acupuncture and behavioral therapy. The discussed pharmacological methods include treatment with beta-blockers, topimarate, flunarizine or one of the latest methods - the use of monoclonal antibodies against CGRP. In addition, the use of botulinum toxin type A in the treatment of chronic migraine has also been demonstrated. It should be remembered that the type of therapy chosen should be individualized: according to the patient's preferences, treatment effectiveness, possible side effects or accompanying diseases. Proper management of chronic migraine prophylaxis can significantly improve the quality of life of patients and reduce the frequency of headache attacks