Protein C activation on the surface of the endothelium is critical to the negative regulation of blood coagulation. We now demonstrate that monoclonal antibodies that block protein C binding to the endothelial cell protein C receptor (EPCR) reduce protein C activation rates by the thrombin-thrombomodulin complex on endothelium, but that antibodies that bind to EPCR without blocking protein C binding have no effect. The kinetic result of blocking the EPCR-protein C interaction is an increased apparent Km for the activation without altering the affinity of thrombin for thrombomodulin. Activation rates of the protein C derivative lacking the gamma-carboxyglutamic acid domain, which is required for binding to EPCR, are not altered by the anti-EPCR antibodies. These data indicate that the protein C activation complex involves protein C, thrombin, thrombomodulin, and EPCR. These observations open new questions about the control of coagulation reactions on vascular endothelium.
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http://dx.doi.org/10.1073/pnas.93.19.10212 | DOI Listing |
J Exp Bot
January 2025
Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy.
Group A basic leucine zipper (bZIP) transcription factors play critical roles in abscisic acid (ABA) signaling and plant development. In Arabidopsis thaliana, these factors are defined by a highly conserved core bZIP domain, and four conserved domains throughout their length: three at the N-terminus (C1 to C3) and a phosphorylatable C-terminal SAP motif located at the C4 domain. Initially, members such as ABI5 and ABFs were studied for their roles in ABA signaling during seed germination or stress responses.
View Article and Find Full Text PDFJ Exp Bot
January 2025
National Institute of Science and Technology on Plant Physiology under Stress Conditions, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, Minas Gerais, Brazil.
The transport of metabolites across the inner mitochondrial membrane (IMM) is crucial for maintaining energy balance and efficient distribution of metabolic intermediates between cellular compartments. Under abiotic stress, mitochondrial function becomes particularly critical, activating complex signaling pathways essential for plant stress responses. These pathways modulate stress-responsive gene expression, influencing key physiological processes such as cell respiration and senescence, helping plants adapt to stress.
View Article and Find Full Text PDFCell Rep
January 2025
Ministry of Education Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, China; Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang Provincial Key Laboratory of Pancreatic Disease, School of Medicine, Zhejiang University, Hangzhou, China; Cancer Center, Zhejiang University, Hangzhou, China. Electronic address:
Arginine methylation is a common post-translational modification that plays critical roles in many biological processes. However, the existence of arginine demethylases that remove the modification has not been fully established. Here, we report that Myc-induced nuclear antigen 53 (Mina53), a member of the jumonji C (JmjC) protein family, is an arginine demethylase.
View Article and Find Full Text PDFCancer Biol Ther
December 2025
Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, USA.
Adaptive immune resistance in cancer describes the various mechanisms by which tumors adapt to evade anti-tumor immune responses. IFN-γ induction of programmed death-ligand 1 (PD-L1) was the first defined and validated adaptive immune resistance mechanism. The endoplasmic reticulum (ER) is central to adaptive immune resistance as immune modulatory secreted and integral membrane proteins are dependent on ER.
View Article and Find Full Text PDFWest Afr J Med
September 2024
Urology Department, Dorset County Hospital, Dorchester, UK.
Introduction: Prostate cancer (PCa) is the commonest urologic cancer worldwide and the leading cause of male cancer deaths in Nigeria. In Nigeria, orchidectomy remains the primary androgen deprivation therapy. Dihydrotestosterone (DHT) is the active prostatic androgen, but its relationship with PCa severity has not been extensively studied in Africa.
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