Protein kinase autophosphorylation of activation segment residues is a common regulatory mechanism in phosphorylation-dependent signalling cascades. However, the molecular mechanisms that guarantee specific and efficient phosphorylation of these sites have not been elucidated. Here, we report on three novel and diverse protein kinase structures that reveal an exchanged activation segment conformation. This dimeric arrangement results in an active kinase conformation in trans, with activation segment phosphorylation sites in close proximity to the active site of the interacting protomer. Analytical ultracentrifugation and chemical cross-linking confirmed the presence of dimers in solution. Consensus substrate sequences for each kinase showed that the identified activation segment autophosphorylation sites are non-consensus substrate sites. Based on the presented structural and functional data, a model for specific activation segment phosphorylation at non-consensus substrate sites is proposed that is likely to be common to other kinases from diverse subfamilies.
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http://dx.doi.org/10.1038/emboj.2008.8 | DOI Listing |
Cureus
December 2024
Physiology, Taibah University, Al-Madinah al-Munawarah, SAU.
Vitiligo is a common autoimmune disease that progressively destroys melanocytes in the skin, resulting in the appearance of patchy depigmentation. The aim of this review is to increase awareness towards vitiligo by providing insight on the pathogenesis and management options. Vitiligo is an acquired pigmentary skin disease, which can appear with one or a few macules.
View Article and Find Full Text PDFCureus
December 2024
Medicine, Florida International University, Herbert Wertheim College of Medicine, Miami, USA.
Our case report characterizes a rare presentation of mid-ventricular Takotsubo cardiomyopathy (TTC) in a patient with suspected myocarditis as an underlying cause. Mid-ventricular TTC is a rare variant of TTC presenting with overlapping symptoms and physical exam findings of acute coronary syndrome, which often leads to misdiagnosis as myocardial infarction. Our case is of a 77-year-old female patient with a history of hyperlipidemia, right breast ductal carcinoma in situ, and diverticular disease who presented to the emergency department for evaluation of chest pain radiating to the jaw with associated nausea and vomiting.
View Article and Find Full Text PDFJ Imaging Inform Med
January 2025
School of Electrical and Electronic Engineering, Hanoi University of Science and Technology, Hanoi, Vietnam.
The field of medical image segmentation powered by deep learning has recently received substantial attention, with a significant focus on developing novel architectures and designing effective loss functions. Traditional loss functions, such as Dice loss and Cross-Entropy loss, predominantly rely on global metrics to compare predictions with labels. However, these global measures often struggle to address challenges such as occlusion and nonuni-form intensity.
View Article and Find Full Text PDFCommun Biol
January 2025
Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA.
Rod and cone photoreceptor cells are specialized neurons responsible for transforming the information reaching the eyes in the form of photons into the language of neuronal activity. Rods are the most prevalent photoreceptor type, primarily responsible for light detection under conditions of limited illumination. Here we demonstrate that human rods have a morphological organization unique among all described species, whereby the cell soma extends alongside the light-sensitive outer segment compartment to form a structure we have termed the "accessory inner segment.
View Article and Find Full Text PDFEur J Trauma Emerg Surg
January 2025
Julius Wolff Institute, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
Background: Flail chest (FC) injuries are segmental osseous injuries of the thorax that typically result from high-energy blunt trauma and regularly occur in multiple trauma (MT) patients. FC injuries are associated with paradoxical chest wall movements and, thus, have a high risk of respiratory insufficiency or even death. An increasing number of studies recommend an early surgical stabilization of FC injuries, but a definite trigger that would indicate surgery has, thus far, not been identified.
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