98%
921
2 minutes
20
Cellular metabolic fluxes are determined by enzyme activities and metabolite abundances. Biochemical approaches reveal the impact of specific substrates or regulators on enzyme kinetics but do not capture the extent to which metabolite and enzyme concentrations vary across physiological states and, therefore, how cellular reactions are regulated. We measured enzyme and metabolite concentrations and metabolic fluxes across 25 steady-state yeast cultures. We then assessed the extent to which flux can be explained by a Michaelis-Menten relationship between enzyme, substrate, product, and potential regulator concentrations. This revealed three previously unrecognized instances of cross-pathway regulation, which we biochemically verified. One of these involved inhibition of pyruvate kinase by citrate, which accumulated and thereby curtailed glycolytic outflow in nitrogen-limited yeast. Overall, substrate concentrations were the strongest driver of the net rates of cellular metabolic reactions, with metabolite concentrations collectively having more than double the physiological impact of enzymes.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5414049 | PMC |
http://dx.doi.org/10.1126/science.aaf2786 | DOI Listing |
Arch Med Res
September 2025
Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan. Electronic address:
Background: Atherosclerosis, a leading cause of cardiovascular disease (CVD) mortality worldwide, is characterized by dysregulated lipid metabolism and unresolved inflammation. Macrophage-derived foam cell formation and apoptosis contribute to plaque formation and vulnerability. Elevated serum galectin-3 (Gal-3) levels are associated with increased CVD risk, and Gal-3 in plaques is strongly associated with macrophages.
View Article and Find Full Text PDFChannels (Austin)
December 2025
Biorheology Research Laboratory, Faculty of Health, Griffith University, Gold Coast, Australia.
The hallmarks of mechanosensitive ion channels have been observed for half a century in various cell lines, although their mechanisms and molecular identities remained unknown until recently. Identification of the bona fide mammalian mechanosensory Piezo channels resulted in an explosion of research exploring the translation of mechanical cues into biochemical signals and dynamic cell morphology responses. One of the Piezo isoforms - Piezo1 - is integral in the erythrocyte (red blood cell; RBC) membrane.
View Article and Find Full Text PDFJ Med Chem
September 2025
State Key Laboratory of Advanced Drug Delivery and Release Systems, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
Resistance-conferring mutations in the androgen receptor (AR) ligand-binding pocket (LBP) compromise the effectiveness of clinically approved orthosteric AR antagonists. Targeting the dimerization interface pocket (DIP) of AR presents a promising therapeutic approach. In this study, we report the design and optimization of -(thiazol-2-yl) furanamide derivatives as novel AR DIP antagonists, among which was the most promising candidate.
View Article and Find Full Text PDFPol Merkur Lekarski
September 2025
FACULTY OF NURSING, UNIVERSITY OF KUFA, KUFA, IRAQ.
Objective: Aim: To evaluate clinical applicability of immune mediator's interleukin-16, immunoglobulin E along with eosinophil count in diagnosing COVID-19 and determining its severity.
Patients And Methods: Materials and Methods: Cross-sectional case-control study was conducted at Al-Najaf General Hospital, Najaf, Iraq between March and August 2024. 120 participants: 60 confirmed COVID-19 cases and 60 healthy controls which matched cases in terms of age and sex.
Mem Inst Oswaldo Cruz
September 2025
Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório Interdisciplinar de Pesquisas Médicas, Rio de Janeiro, RJ, Brasil.
Background: Parasite antigens and plasma lipopolysaccharide (LPS) levels from luminal origin in visceral leishmaniasis (VL) patients are correlated with cellular activation and low CD4+T cell counts.
Objectives: Our aim was to verify whether Leishmania infantum infection damages the intestinal barrier and whether combination antimonial/antibiotic contributes to the reduction of LPS levels and immune activation.
Methods: Golden hamsters were grouped in: G1-uninfected; G2-infected with L.