Spleen Tyrosine Kinase (Syk) plays a crucial role in immune cell signalling and its altered expression or activation are involved in several cancers. Syk activity relies on its phosphorylation status and its multiple phosphorylation sites predict several Syk conformations. In this report, we characterized Syk structural changes according to its phosphorylation/activation status by Surface Enhanced Raman Spectroscopy (SERS). Unphosphorylated/inactive and phosphorylated/active Syk forms were produced into two expression systems with different phosphorylation capability. Syk forms were then analysed by SERS that was carried out in liquid condition on a lithographically designed gold nanocylinders array. Our study demonstrated that SERS signatures of the two Syk forms were drastically distinct, indicating structural modifications related to their phosphorylation status. By comparison with the atomic structure of the unphosphorylated Syk, the SERS peak assignments of the phosphorylated Syk nearest gold nanostructures revealed a differential interaction with the gold surface. We finally described a model for Syk conformational variations according to its phosphorylation status. In conclusion, SERS is an efficient technical approach for studying in vitro protein conformational changes and might be a powerful tool to determine protein functions in tumour cells.
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http://dx.doi.org/10.1038/srep39766 | DOI Listing |
Alzheimers Dement
January 2025
Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Introduction: Using an Asian cohort with high prevalence of concomitant cerebrovascular disease (CeVD), we evaluated the performance of a plasma immunoassay for tau phosphorylated at threonine 217 (p-tau217) in detecting amyloid beta positivity (Aβ+) on positron emission tomography and cognitive decline, based on a three-range reference, which stratified patients into low-, intermediate-, and high-risk groups for Aβ+.
Methods: Brain amyloid status (Aβ- [n = 142] vs Aβ+ [n = 73]) on amyloid PET scans was assessed along with the plasma ALZpath p-tau217 assay to derive three-range reference points for PET Aβ+ based on 90% sensitivity (lower threshold) and 90% specificity (upper threshold).
Results: Plasma p-tau217 (area under the curve [AUC] = 0.
J Endocr Soc
January 2025
Biochemistry Section, Faculty of Environmental Sciences and UCLM Institute of Biomedicine (IB-UCLM), 45071 Toledo, Castilla-La Mancha, Spain.
The hypothalamus integrates peripheral signals and modulates food intake and energy expenditure by regulating the metabolic function of peripheral tissues, including the liver and adipose tissue. In a previous study, we demonstrated that s-resistin, an intracellular resistin isoform highly expressed in the hypothalamus and upregulated during aging, is important in the central control of energy homeostasis, affecting mainly the peripheral response to insulin by still unknown mechanisms. Herein, using an intracerebroventricular injection of a specific lentiviral RNAi against s-resistin, we assessed, in the Wistar rat, the effects of central s-resistin downregulation on the expression and phosphorylation levels of intermediates involved in insulin signaling and the inflammatory response in epididymal white adipose tissue (eWAT) and liver.
View Article and Find Full Text PDFRespir Res
January 2025
Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
Background: Obstructive sleep apnea (OSA) is frequently associated with increased incidence and mortality of pulmonary hypertension (PH). The immune response contributes to pulmonary artery remodeling and OSA-related diseases. The immunologic factors linked to OSA-induced PH are not well understood.
View Article and Find Full Text PDFCancer Drug Resist
December 2024
Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Bratislava 84505, Slovak Republic.
Mutations in the mitochondrial (mt) genome contribute to metabolic dysfunction and their accumulation relates to disease progression and resistance development in cancer cells. This study explores the mutational status of the mt genome of cisplatin-resistant -sensitive testicular germ cell tumor (TGCT) cells and explores its association with their respiration parameters, expression of respiratory genes, and preferences for metabolic pathways to reveal new markers of therapy resistance in TGCTs. Using Illumina sequencing with Twist Enrichment Panel, the mutations of mt genomes of sensitive 2102EP, H12.
View Article and Find Full Text PDFTheriogenology
January 2025
Department of Animal Science and Biotechnology, Kyungpook National University, Sangju, 37224, Republic of Korea; Research Institute for Innovative Animal Science, Kyungpook National University, Sangju, 37224, Republic of Korea. Electronic address:
Spermatozoa must undergo a complex maturation process within the female genital tract known as capacitation. This process entails the phosphorylation or dephosphorylation of various proteins, and multiple signaling pathways are recognized to play a role. The present study aims to identify alterations in the expression of proteins related to the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT) signaling pathway and assess sperm functions during capacitation.
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